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Sonke Johnsen

Ida Stephens Owens Distinguished Professor
Biology
Duke Box 90338, Durham, NC 27708-0338
301 Bio Sci Bldg, Durham, NC 27708

Selected Publications


Animal magnetic sensitivity and magnetic displacement experiments.

Journal Article Communications biology · May 2024 Full text Cite

Backgrounds and the evolution of visual signals.

Journal Article Trends in ecology & evolution · February 2024 Color signals which mediate behavioral interactions across taxa and contexts are often thought of as color 'patches' - parts of an animal that appear colorful compared to other parts of that animal. Color patches, however, cannot be considered in isolation ... Full text Cite

Learning without a brain: classical conditioning in the ophiuroid Ophiocoma echinata

Journal Article Behavioral Ecology and Sociobiology · November 1, 2023 Brittle stars (Class Ophiuroidea), like all echinoderms, lack centralized nervous systems, having instead five radially arranged nerve cords joined by a central nerve ring. Although operant and classical conditioning have been demonstrated in a limited num ... Full text Cite

Cephalopod versus vertebrate eyes.

Journal Article Current biology : CB · October 2023 Vertebrates and cephalopods are the two major animal groups that view the world through sophisticated camera-type eyes. There are of course exceptions: nautiloid cephalopods have more simply built pinhole eyes. Excellent camera type eyes are also found in ... Full text Cite

Measures and models of visual acuity in epipelagic and mesopelagic teleosts and elasmobranchs.

Journal Article Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · September 2023 Eyes in low-light environments typically must balance sensitivity and spatial resolution. Vertebrate eyes with large "pixels" (e.g., retinal ganglion cells with inputs from many photoreceptors) will be sensitive but provide coarse vision. Small pixels can ... Full text Cite

The carotenoid redshift: Physical basis and implications for visual signaling.

Journal Article Ecology and evolution · September 2023 Carotenoid pigments are the basis for much red, orange, and yellow coloration in nature and central to visual signaling. However, as pigment concentration increases, carotenoid signals not only darken and become more saturated but they also redshift; for e ... Full text Cite

Dynamic light filtering over dermal opsin as a sensory feedback system in fish color change.

Journal Article Nature communications · August 2023 Dynamic color change has evolved multiple times, with a physiological basis that has been repeatedly linked to dermal photoreception via the study of excised skin preparations. Despite the widespread prevalence of dermal photoreception, both its physiology ... Full text Cite

An Investigation into the Mechanism Mediating Counterillumination in Myctophid Fishes (Myctophidae).

Journal Article The Biological bulletin · February 2023 AbstractCounterillumination is a camouflage strategy employed primarily by mesopelagic fishes, sharks, crustaceans, and squid, which use ventral bioluminescence to obscure their silhouettes when viewed from below. Although certain counterilluminating speci ... Full text Cite

Glassfrogs conceal blood in their liver to maintain transparency.

Journal Article Science (New York, N.Y.) · December 2022 Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cell ... Full text Cite

Collective movement as a solution to noisy navigation and its vulnerability to population loss.

Journal Article Proceedings. Biological sciences · November 2022 Many animals use the geomagnetic field to migrate long distances with high accuracy; however, research has shown that individual responses to magnetic cues can be highly variable. Thus, it has been hypothesized that magnetoreception alone is insufficient f ... Full text Cite

The movement ecology of fishes.

Journal Article Journal of fish biology · October 2022 Movement of fishes in the aquatic realm is fundamental to their ecology and survival. Movement can be driven by a variety of biological, physiological and environmental factors occurring across all spatial and temporal scales. The intrinsic capacity of mov ... Full text Cite

In the field: an interview with Sönke Johnsen

Journal Article Journal of Experimental Biology · August 1, 2022 Full text Cite

Testing Mechanisms of Vision: Sea Urchin Spine Density Does Not Correlate With Vision-Related Environmental Characteristics.

Journal Article Integrative and comparative biology · July 2022 Sea urchins do not have eyes, yet they are capable of resolving simple images. One suggestion as to the mechanism of this capability is that the spines shade off-axis light from reaching the photosensitive test (skeleton). Following this hypothesis, the de ... Full text Cite

Influence of visual background on discrimination of signal-relevant colours in zebra finches (Taeniopygia guttata).

Journal Article Proceedings. Biological sciences · June 2022 Colour signals of many animals are surrounded by a high-contrast achromatic background, but little is known about the possible function of this arrangement. For both humans and non-human animals, the background colour surrounding a colour stimulus affects ... Full text Open Access Cite

Macropinna.

Journal Article Current biology : CB · March 2022 Sönke Johnsen and Steve Haddock introduce the remarkable deep-sea fish Macropinna microstoma whose transparent head and rotating tubular eyes are two novel adaptations that allow it to see and hunt at depth. ... Full text Cite

Testosterone, signal coloration, and signal color perception in male zebra finch contests.

Journal Article Ethology : formerly Zeitschrift fur Tierpsychologie · February 2022 Many animals use assessment signals to resolve contests over limited resources while minimizing the costs of those contests. The carotenoid-based orange to red bills of male zebra finches (Taeniopygia guttata) are thought to function as assessment s ... Full text Open Access Cite

Environmental sources of radio frequency noise: potential impacts on magnetoreception.

Journal Article Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · January 2022 Radio frequency electromagnetic noise (RF) of anthropogenic origin has been shown to disrupt magnetic orientation behavior in some animals. Two sources of natural RF might also have the potential to disturb magnetic orientation behavior under some conditio ... Full text Cite

Macropinna

Journal Article CURRENT BIOLOGY · 2022 Open Access Cite

Light as an Ecological Resource

Chapter · January 1, 2022 This chapter discusses the use of light by aquatic organisms for visual and non-visual tasks that often enhance fitness. Variations in underwater light among inland waters as well as mechanisms of photoreception (i.e., light capture) are first described. T ... Full text Cite

The visual ecology of selective predation: Are unhealthy hosts less stealthy hosts?

Journal Article Ecology and Evolution · December 1, 2021 Predators can strongly influence disease transmission and evolution, particularly when they prey selectively on infected hosts. Although selective predation has been observed in numerous systems, why predators select infected prey remains poorly understood ... Full text Cite

Animal magnetic sensitivity and magnetic displacement experiments.

Journal Article Communications biology · May 2024 Full text Cite

Backgrounds and the evolution of visual signals.

Journal Article Trends in ecology & evolution · February 2024 Color signals which mediate behavioral interactions across taxa and contexts are often thought of as color 'patches' - parts of an animal that appear colorful compared to other parts of that animal. Color patches, however, cannot be considered in isolation ... Full text Cite

Learning without a brain: classical conditioning in the ophiuroid Ophiocoma echinata

Journal Article Behavioral Ecology and Sociobiology · November 1, 2023 Brittle stars (Class Ophiuroidea), like all echinoderms, lack centralized nervous systems, having instead five radially arranged nerve cords joined by a central nerve ring. Although operant and classical conditioning have been demonstrated in a limited num ... Full text Cite

Cephalopod versus vertebrate eyes.

Journal Article Current biology : CB · October 2023 Vertebrates and cephalopods are the two major animal groups that view the world through sophisticated camera-type eyes. There are of course exceptions: nautiloid cephalopods have more simply built pinhole eyes. Excellent camera type eyes are also found in ... Full text Cite

Measures and models of visual acuity in epipelagic and mesopelagic teleosts and elasmobranchs.

Journal Article Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · September 2023 Eyes in low-light environments typically must balance sensitivity and spatial resolution. Vertebrate eyes with large "pixels" (e.g., retinal ganglion cells with inputs from many photoreceptors) will be sensitive but provide coarse vision. Small pixels can ... Full text Cite

The carotenoid redshift: Physical basis and implications for visual signaling.

Journal Article Ecology and evolution · September 2023 Carotenoid pigments are the basis for much red, orange, and yellow coloration in nature and central to visual signaling. However, as pigment concentration increases, carotenoid signals not only darken and become more saturated but they also redshift; for e ... Full text Cite

Dynamic light filtering over dermal opsin as a sensory feedback system in fish color change.

Journal Article Nature communications · August 2023 Dynamic color change has evolved multiple times, with a physiological basis that has been repeatedly linked to dermal photoreception via the study of excised skin preparations. Despite the widespread prevalence of dermal photoreception, both its physiology ... Full text Cite

An Investigation into the Mechanism Mediating Counterillumination in Myctophid Fishes (Myctophidae).

Journal Article The Biological bulletin · February 2023 AbstractCounterillumination is a camouflage strategy employed primarily by mesopelagic fishes, sharks, crustaceans, and squid, which use ventral bioluminescence to obscure their silhouettes when viewed from below. Although certain counterilluminating speci ... Full text Cite

Glassfrogs conceal blood in their liver to maintain transparency.

Journal Article Science (New York, N.Y.) · December 2022 Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cell ... Full text Cite

Collective movement as a solution to noisy navigation and its vulnerability to population loss.

Journal Article Proceedings. Biological sciences · November 2022 Many animals use the geomagnetic field to migrate long distances with high accuracy; however, research has shown that individual responses to magnetic cues can be highly variable. Thus, it has been hypothesized that magnetoreception alone is insufficient f ... Full text Cite

The movement ecology of fishes.

Journal Article Journal of fish biology · October 2022 Movement of fishes in the aquatic realm is fundamental to their ecology and survival. Movement can be driven by a variety of biological, physiological and environmental factors occurring across all spatial and temporal scales. The intrinsic capacity of mov ... Full text Cite

In the field: an interview with Sönke Johnsen

Journal Article Journal of Experimental Biology · August 1, 2022 Full text Cite

Testing Mechanisms of Vision: Sea Urchin Spine Density Does Not Correlate With Vision-Related Environmental Characteristics.

Journal Article Integrative and comparative biology · July 2022 Sea urchins do not have eyes, yet they are capable of resolving simple images. One suggestion as to the mechanism of this capability is that the spines shade off-axis light from reaching the photosensitive test (skeleton). Following this hypothesis, the de ... Full text Cite

Influence of visual background on discrimination of signal-relevant colours in zebra finches (Taeniopygia guttata).

Journal Article Proceedings. Biological sciences · June 2022 Colour signals of many animals are surrounded by a high-contrast achromatic background, but little is known about the possible function of this arrangement. For both humans and non-human animals, the background colour surrounding a colour stimulus affects ... Full text Open Access Cite

Macropinna.

Journal Article Current biology : CB · March 2022 Sönke Johnsen and Steve Haddock introduce the remarkable deep-sea fish Macropinna microstoma whose transparent head and rotating tubular eyes are two novel adaptations that allow it to see and hunt at depth. ... Full text Cite

Testosterone, signal coloration, and signal color perception in male zebra finch contests.

Journal Article Ethology : formerly Zeitschrift fur Tierpsychologie · February 2022 Many animals use assessment signals to resolve contests over limited resources while minimizing the costs of those contests. The carotenoid-based orange to red bills of male zebra finches (Taeniopygia guttata) are thought to function as assessment s ... Full text Open Access Cite

Environmental sources of radio frequency noise: potential impacts on magnetoreception.

Journal Article Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · January 2022 Radio frequency electromagnetic noise (RF) of anthropogenic origin has been shown to disrupt magnetic orientation behavior in some animals. Two sources of natural RF might also have the potential to disturb magnetic orientation behavior under some conditio ... Full text Cite

Macropinna

Journal Article CURRENT BIOLOGY · 2022 Open Access Cite

Light as an Ecological Resource

Chapter · January 1, 2022 This chapter discusses the use of light by aquatic organisms for visual and non-visual tasks that often enhance fitness. Variations in underwater light among inland waters as well as mechanisms of photoreception (i.e., light capture) are first described. T ... Full text Cite

The visual ecology of selective predation: Are unhealthy hosts less stealthy hosts?

Journal Article Ecology and Evolution · December 1, 2021 Predators can strongly influence disease transmission and evolution, particularly when they prey selectively on infected hosts. Although selective predation has been observed in numerous systems, why predators select infected prey remains poorly understood ... Full text Cite

Studying the swift, smart, and shy: Unobtrusive camera-platforms for observing large deep-sea squid

Journal Article Deep-Sea Research Part I: Oceanographic Research Papers · June 1, 2021 The legend of the “kraken” has captivated humans for millennia, yet our knowledge of the large deep-sea cephalopods that inspired this myth remains limited. Conventional methods for exploring the deep sea, including the use of nets, manned submersibles, an ... Full text Cite

The sensory impacts of climate change: bathymetric shifts and visually mediated interactions in aquatic species.

Journal Article Proceedings. Biological sciences · April 2021 Visual perception is, in part, a function of the ambient illumination spectrum. In aquatic environments, illumination depends upon the water's optical properties and depth, both of which can change due to anthropogenic impacts: turbidity is increasing in m ... Full text Cite

The orbital hoods of snapping shrimp have surface features that may represent tradeoffs between vision and protection.

Journal Article Arthropod structure & development · March 2021 Snapping shrimp (Alpheidae) are decapod crustaceans named for the snapping claws with which they produce cavitation bubbles. Snapping shrimp use the shock waves released by collapsing cavitation bubbles as weapons. Along with their distinctive claws, snapp ... Full text Cite

Comparison of Categorical Color Perception in Two Estrildid Finches.

Journal Article The American naturalist · February 2021 Featured Publication AbstractSensory systems are predicted to be adapted to the perception of important stimuli, such as signals used in communication. Prior work has shown that female zebra finches perceive the carotenoid-based orange-red coloration of male beaks-a mate choic ... Full text Open Access Cite

Differences in categorical color perception between two estrildid finches

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2021 Cite

Hiding in the deep: ultra-black camouflage in fishes

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2021 Cite

Magnetoreception and the radio sun

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2021 Cite

Ultra-Black Deep-Sea Fishes

Journal Article Optics and Photonics News · December 1, 2020 Ultra-black materials—those reflecting less than 0.5[%] of the light that hits them—can be used in telescopes, cameras and optical equipment to absorb stray light before it reaches the detector, or to improve light capture of absorbers such as solar panels ... Full text Cite

Pulse magnetization elicits differential gene expression in the central nervous system of the Caribbean spiny lobster, Panulirus argus.

Journal Article Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · September 2020 Diverse animals use Earth's magnetic field to guide their movements, but the neural and molecular mechanisms underlying the magnetic sense remain enigmatic. One hypothesis is that particles of the mineral magnetite (Fe3O4) provide the ... Full text Cite

Ultra-black Camouflage in Deep-Sea Fishes.

Journal Article Current biology : CB · September 2020 At oceanic depths >200 m, there is little ambient sunlight, but bioluminescent organisms provide another light source that can reveal animals to visual predators and prey [1-4]. Transparency and mirrored surfaces-common camouflage strategies under the diff ... Full text Cite

Visual perception of light organ patterns in deep-sea shrimps and implications for conspecific recognition.

Journal Article Ecology and evolution · September 2020 Darkness and low biomass make it challenging for animals to find and identify one another in the deep sea. While spatiotemporal variation in bioluminescence is thought to underlie mate recognition for some species, its role in conspecific recognition remai ... Full text Cite

Animal navigation: a noisy magnetic sense?

Journal Article The Journal of experimental biology · September 2020 Diverse organisms use Earth's magnetic field as a cue in orientation and navigation. Nevertheless, eliciting magnetic orientation responses reliably, either in laboratory or natural settings, is often difficult. Many species appear to preferentially exploi ... Full text Cite

Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · August 2020 Many vertebrates have distinctive blue-green bones and other tissues due to unusually high biliverdin concentrations-a phenomenon called chlorosis. Despite its prevalence, the biochemical basis, biology, and evolution of chlorosis are poorly understood. In ... Full text Cite

Variation in carotenoid-containing retinal oil droplets correlates with variation in perception of carotenoid coloration

Journal Article Behavioral Ecology and Sociobiology · July 1, 2020 Abstract: In the context of mate choice, males may vary continuously in their expression of assessment signals, typically reflecting information about variation in mate quality. Similarly, females may exhibit variation in mate preference, which could be du ... Full text Open Access Cite

Evidence that eye-facing photophores serve as a reference for counterillumination in an order of deep-sea fishes.

Journal Article Proceedings. Biological sciences · June 2020 Counterillumination, the masking of an animal's silhouette with ventral photophores, is found in a number of mesopelagic taxa but is difficult to employ because it requires that the animal match the intensity of downwelling light without seeing its own ven ... Full text Cite

Effect of a magnetic pulse on orientation behavior in rainbow trout (Oncorhynchus mykiss).

Journal Article Behavioural processes · March 2020 Magnetoreception remains one of the most enigmatic of animal senses. Rainbow trout (Oncorhynchus mykiss) represent an ideal species to study this sense, as magnetoreception based upon microscopic particles of magnetite is suspected to play an important rol ... Full text Cite

Diverse nanostructures underlie thin ultra-black scales in butterflies.

Journal Article Nature communications · March 2020 Recently, it has been shown that animals such as jumping spiders, birds, and butterflies have evolved ultra-black coloration comparable to the blackest synthetic materials. Of these, certain papilionid butterflies have reflectances approaching 0.2%, result ... Full text Cite

Gray whales strand more often on days with increased levels of atmospheric radio-frequency noise.

Journal Article Current biology : CB · February 2020 Evidence from live gray whale strandings suggests that their navigation may be disrupted by increased radio frequency noise generated by solar storms, suggesting the potential for magnetoreception in this species. ... Full text Cite

How our perceptual and cognitive biases may influence our study of animal vision

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2020 Cite

Convergent evolution of ultra-black butterfly scales

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2020 Cite

Associative learning in the brittle star Ophioderma brevispinum

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2020 Cite

How and why are the blue eyes of scallops blue?

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2020 Cite

Trends in Spatial Acuity Across the Sea Urchins

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · 2020 Cite

Novel mitochondrial derived Nuclear Excisosome degrades nuclei during differentiation of prosimian Galago (bush baby) monkey lenses.

Journal Article PloS one · January 2020 The unique cellular organization and transparent function of the ocular lens depend on the continuous differentiation of immature epithelial cells on the lens anterior surface into mature elongated fiber cells within the lens core. A ubiquitous event durin ... Full text Cite

Journey into Midnight

Journal Article OCEANOGRAPHY · 2020 Cite

1.02 - Light and Visual Environments

Chapter · January 1, 2020 This review explores the physical properties of natural light, both celestial and bioluminescent, and its distribution in terrestrial and aquatic habitats. A description of the natural sources of light is followed by a discussion of the spatial, temporal, ... Full text Cite

Von Uexküll Revisited: Addressing Human Biases in the Study of Animal Perception.

Journal Article Integrative and comparative biology · December 2019 More than 100 years ago, the biologist Jakob von Uexküll suggested that, because sensory systems are diverse, animals likely inhabit different sensory worlds (umwelten) than we do. Since von Uexküll, work across sensory modalities has confirmed that animal ... Full text Open Access Cite

Core-shell nanospheres behind the blue eyes of the bay scallop Argopecten irradians.

Journal Article Journal of the Royal Society, Interface · October 2019 The bay scallop Argopecten irradians (Mollusca: Bivalvia) has dozens of iridescent blue eyes that focus light using mirror-based optics. Here, we test the hypothesis that these eyes appear blue because of photonic nanostructures that preferentially ... Full text Cite

The cleaner shrimp Lysmata amboinensis adjusts its behaviour towards predatory versus non-predatory clients.

Journal Article Biology letters · September 2019 In cleaning mutualisms, small cleaner organisms remove ectoparasites and dead skin from larger clients. Because cheating by predatory clients can result in cleaner death, cleaners should assess the potential risk of interacting with a given client and adju ... Full text Cite

Variation in rod spectral sensitivity of fishes is best predicted by habitat and depth.

Journal Article Journal of fish biology · July 2019 Rod spectral sensitivity data (λmax ), measured by microspectrophotometry, were compiled for 403 species of ray-finned fishes in order to examine four hypothesized predictors of rod spectral sensitivity (depth, habitat, diet and temperature). Fr ... Full text Cite

Categorical colour perception occurs in both signalling and non-signalling colour ranges in a songbird.

Journal Article Proceedings. Biological sciences · May 2019 Although perception begins when a stimulus is transduced by a sensory neuron, numerous perceptual mechanisms can modify sensory information as it is processed by an animal's nervous system. One such mechanism is categorical perception, in which (1) continu ... Full text Cite

Patterns and Predictors of Spectral Sensitivity Variation in Fishes

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2019 Link to item Cite

Categorical Perception of a Carotenoid-based Assessment Signal

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2019 Link to item Cite

Sea Urchin Vision in Featureless vs. Spatially Complex Environments

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2019 Link to item Cite

Polarisation signals: a new currency for communication.

Journal Article The Journal of experimental biology · February 2019 Most polarisation vision studies reveal elegant examples of how animals, mainly the invertebrates, use polarised light cues for navigation, course-control or habitat selection. Within the past two decades it has been recognised that polarised light, reflec ... Full text Cite

Genomic signatures of G-protein-coupled receptor expansions reveal functional transitions in the evolution of cephalopod signal transduction.

Journal Article Proceedings. Biological sciences · February 2019 Coleoid cephalopods show unique morphological and neural novelties, such as arms with tactile and chemosensory suckers and a large complex nervous system. The evolution of such cephalopod novelties has been attributed at a genomic level to independent gene ... Full text Cite

Orienting to polarized light at night - matching lunar skylight to performance in a nocturnal beetle.

Journal Article The Journal of experimental biology · January 2019 For polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal's natural environment must be above the threshold for detection and interpretation. Here, we present the first investigation of the degree of lin ... Full text Cite

Spectral sensitivity in ray-finned fishes: diversity, ecology and shared descent.

Journal Article The Journal of experimental biology · November 2018 A major goal of sensory ecology is to identify factors that underlie sensory-trait variation. One open question centers on why fishes show the greatest diversity among vertebrates in their capacity to detect color (i.e. spectral sensitivity). Over the past ... Full text Cite

New NSF policy will stifle innovation.

Journal Article Science (New York, N.Y.) · October 2018 Full text Cite

Orientation in Pill Bugs: An Interdisciplinary Activity to Engage Students in Concepts of Biology, Physics & Circular Statistics

Journal Article American Biology Teacher · October 1, 2018 We present a novel laboratory activity to introduce students to experimental approaches often used by biologists to study orientation in animals. We first provide an overview of the current understanding of magnetoreception-the ability of some organisms to ... Full text Cite

Categorical perception of colour signals in a songbird.

Journal Article Nature · August 2018 In many contexts, animals assess each other using signals that vary continuously across individuals and, on average, reflect variation in the quality of the signaller1,2. It is often assumed that signal receivers perceive and respond continuousl ... Full text Cite

Green sea turtle (Chelonia mydas) population history indicates important demographic changes near the mid-Pleistocene transition

Journal Article Marine Biology · July 1, 2018 The increased availability of genome sequences has provided remarkable advances in our understanding of the evolutionary history of non-model species. One important consideration in evolutionary studies is the role of demographic history in shaping contemp ... Full text Cite

The Earth's Magnetic Field and Visual Landmarks Steer Migratory Flight Behavior in the Nocturnal Australian Bogong Moth.

Journal Article Current biology : CB · July 2018 Like many birds [1], numerous species of nocturnal moths undertake spectacular long-distance migrations at night [2]. Each spring, billions of Bogong moths (Agrotis infusa) escape hot conditions in different regions of southeast Australia by making a highl ... Full text Cite

Data and scripts from: Categorical perception of colour signals in a songbird

Dataset · June 12, 2018 Categorical perception occurs when continuous variation in a stimulus (e.g., wavelength of color) is categorized by observers, with sharp changes in response occurring over a boundary and increased discrimination between stimuli that lie across a boundary ... Full text Cite

Near absence of differential gene expression in the retina of rainbow trout after exposure to a magnetic pulse: implications for magnetoreception.

Journal Article Biology letters · June 2018 The ability to perceive the Earth's magnetic field, or magnetoreception, exists in numerous animals. Although the mechanism underlying magnetoreception has not been clearly established in any species, in salmonid fish, it is hypothesized to occur by means ... Full text Cite

Mutual visual signalling between the cleaner shrimp Ancylomenes pedersoni and its client fish.

Journal Article Proceedings. Biological sciences · June 2018 Cleaner shrimp and their reef fish clients are an interspecific mutualistic interaction that is thought to be mediated by signals, and a useful system for studying the dynamics of interspecific signalling. To demonstrate signalling, one must show that purp ... Full text Cite

Unmapped sequencing reads identify additional candidate genes linked to magnetoreception in rainbow trout

Journal Article Environmental Biology of Fishes · May 1, 2018 A recent study identified candidate genes linked to magnetoreception in rainbow trout (Oncorhynchus mykiss) by sequencing transcriptomes from the brains of fish exposed to a magnetic pulse. However, the discovery of these candidate genes was limited to seq ... Full text Cite

De novo transcriptomics reveal distinct phototransduction signaling components in the retina and skin of a color-changing vertebrate, the hogfish (Lachnolaimus maximus).

Journal Article Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · May 2018 Across diverse taxa, an increasing number of photoreceptive systems are being discovered in tissues outside of the eye, such as in the skin. Dermal photoreception is believed to serve a variety of functions, including rapid color change via specialized cel ... Full text Cite

Visual Acuity and the Evolution of Signals.

Journal Article Trends in ecology & evolution · May 2018 Acuity, the fineness with which sensory systems perceive and parse information, limits the information that organisms can extract from stimuli. Here, we focus on visual acuity (the ability to perceive static spatial detail) to discuss relationships between ... Full text Cite

AcuityView: An r package for portraying the effects of visual acuity on scenes observed by an animal

Journal Article Methods in Ecology and Evolution · March 1, 2018 Visual acuity is one of three basic parameters that characterize a visual system. However, few comparative studies of signals, camouflage and ecology in general have considered visual acuity. This is unfortunate, because humans have high acuity, and thus r ... Full text Cite

Dermal Photoreception May Provide Sensory Feedback for Dynamic Coloration

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2018 Link to item Cite

Candidate magnetoreception genes in the brain and retina of trout

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2018 Link to item Cite

Visual Ecology of the White Shark and Shortfin Mako

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2018 Link to item Cite

The ultrastructure of transparent shrimp

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2018 Link to item Cite

Do (Eyeless) Sea Urchins Have Color Vision?

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2018 Link to item Cite

Insights into the biodiversity, behavior, and bioluminescence of deep-sea organisms using molecular and maritime technology.

Journal Article Oceanography · December 1, 2017 Since its founding, the Monterey Bay Aquarium Research Institute (MBARI) has pioneered unique capabilities for accessing the deep ocean and its inhabitants through focused peer relationships between scientists and engineers. This focus has enabled breakthr ... Full text Cite

Bringing the analysis of animal orientation data full circle: model-based approaches with maximum likelihood.

Journal Article The Journal of experimental biology · November 2017 In studies of animal orientation, data are often represented as directions that can be analyzed using circular statistical methods. Although several circular statistical tests exist to detect the presence of a mean direction, likelihood-based approaches ma ... Full text Cite

Transparent anemone shrimp (Ancylomenes pedersoni) become opaque after exercise and physiological stress in correlation with increased hemolymph perfusion.

Journal Article The Journal of experimental biology · November 2017 Whole-body transparency, an effective camouflage strategy in many aquatic species, can be disrupted by environmental and/or physiological stressors. We found that tail-flip escape responses temporarily disrupt the transparency of the anemone shrimp Ancy ... Full text Cite

Fluorescence as a means of colour signal enhancement.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · July 2017 Fluorescence is a physico-chemical energy exchange where shorter-wavelength photons are absorbed by a molecule and are re-emitted as longer-wavelength photons. It has been suggested a means of communication in several taxa including flowers, pitcher plants ... Full text Cite

Visual acuity in ray-finned fishes correlates with eye size and habitat.

Journal Article The Journal of experimental biology · May 2017 Visual acuity (the ability to resolve spatial detail) is highly variable across fishes. However, little is known about the evolutionary pressures underlying this variation. We reviewed published literature to create an acuity database for 159 species of ra ... Full text Open Access Cite

Open Questions: We don't really know anything, do we? Open questions in sensory biology.

Journal Article BMC biology · May 2017 Senses connect organisms to both the world and to each other, yet there is much we don't know about them. Using examples drawn primarily from the author's subfield of vision research, this article discusses five major open questions. ... Full text Cite

Detection of magnetic field properties using distributed sensing: a computational neuroscience approach.

Journal Article Bioinspiration & biomimetics · May 2017 Diverse taxa use Earth's magnetic field to aid both short- and long-distance navigation. Study of these behaviors has led to a variety of postulated sensory and processing mechanisms that remain unconfirmed. Although several models have been proposed to ex ... Full text Cite

Coping with copepods: do right whales (Eubalaena glacialis) forage visually in dark waters?

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · April 2017 North Atlantic right whales (Eubalaena glacialis) feed during the spring and early summer in marine waters off the northeast coast of North America. Their food primarily consists of planktonic copepods, Calanus finmarchicus, which they consum ... Full text Cite

Two eyes for two purposes: in situ evidence for asymmetric vision in the cockeyed squids Histioteuthis heteropsis and Stigmatoteuthis dofleini.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · April 2017 The light environment of the mesopelagic realm of the ocean changes with both depth and viewer orientation, and this has probably driven the high diversity of visual adaptations found among its inhabitants. The mesopelagic 'cockeyed' squids of family Histi ... Full text Cite

Candidate genes mediating magnetoreception in rainbow trout (Oncorhynchus mykiss).

Journal Article Biology letters · April 2017 Diverse animals use Earth's magnetic field in orientation and navigation, but little is known about the molecular mechanisms that underlie magnetoreception. Recent studies have focused on two possibilities: (i) magnetite-based receptors; and (ii) biochemic ... Full text Cite

What big eyes you have: Eye allometry and visual range in deep-sea cephalopods

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2017 Link to item Cite

Using RGB displays to portray color realistic imagery to animal eyes.

Journal Article Current zoology · February 2017 RGB displays effectively simulate millions of colors in the eyes of humans by modulating the relative amount of light emitted by 3 differently colored juxtaposed lights (red, green, and blue). The relationship between the ratio of red, green, and blue ligh ... Full text Cite

Extraocular, Non-Visual, and Simple Photoreceptors: An Introduction to the Symposium.

Journal Article Integrative and comparative biology · November 2016 It has been recognized for decades that animals sense light using photoreceptors besides those that are devoted strictly to vision. However, the nature of these receptors, their molecular components, their physiological responses, and their biological func ... Full text Cite

Examining the Effects of Chromatic Aberration, Object Distance, and Eye Shape on Image-Formation in the Mirror-Based Eyes of the Bay Scallop Argopecten irradians.

Journal Article Integrative and comparative biology · November 2016 The eyes of scallops form images using a concave spherical mirror and contain two separate retinas, one layered on top of the other. Behavioral and electrophysiological studies indicate that the images formed by these eyes have angular resolutions of about ... Full text Cite

Nanostructures and Monolayers of Spheres Reduce Surface Reflections in Hyperiid Amphipods.

Journal Article Current biology : CB · November 2016 Transparent zooplankton and nekton are often nearly invisible when viewed under ambient light in the pelagic zone [1-3]. However, in this environment, where the light field is directional (and thus likely to cause reflections), and under the bioluminescent ... Full text Cite

The effect of aggregation on visibility in open water.

Journal Article Proceedings. Biological sciences · September 2016 Aggregation is a common life-history trait in open-water taxa. Qualitative understanding of how aggregation by prey influences their encounter rates with predators is critical for understanding pelagic predator-prey interactions and trophic webs. We extend ... Full text Cite

Disentangling the visual cues used by a jumping spider to locate its microhabitat.

Journal Article The Journal of experimental biology · August 2016 Many arthropod species have evolved to thrive only on the leaves of a particular species of plant, which they must be capable of finding in order to survive accidental displacement, developmental transitions or the changing of the seasons. A number of stud ... Full text Cite

Comment on "Open-ocean fish reveal an omnidirectional solution to camouflage in polarized environments".

Journal Article Science (New York, N.Y.) · August 2016 Brady et al (Reports, 20 November 2015, p. 965) claimed that the silvery sides of certain fish are cryptic when viewed by animals with polarization sensitivity, which they termed "polarocrypsis." After examining their evidence, we find this claim to be uns ... Full text Cite

Polarization vision seldom increases the sighting distance of silvery fish.

Journal Article Current biology : CB · August 2016 Although the function of polarization vision, the ability to discern the polarization characteristics of light, is well established in many terrestrial and benthic species, its purpose in pelagic species (squid and certain fish and crustaceans) is poorly u ... Full text Cite

Modelling colour constancy in fish: implications for vision and signalling in water.

Journal Article The Journal of experimental biology · June 2016 Colour vision and colour signals are important to aquatic animals, but light scattering and absorption by water distorts spectral stimuli. To investigate the performance of colour vision in water, and to suggest how photoreceptor spectral sensitivities and ... Full text Cite

How to measure color using spectrometers and calibrated photographs.

Journal Article The Journal of experimental biology · March 2016 The measurement of color in biology has become increasingly common. These measurements are not limited to color vision research, but are also found in studies of communication, signaling, camouflage, evolution and behavior, and in the examination of enviro ... Full text Cite

Cuttlefish see shape from shading, fine-tuning coloration in response to pictorial depth cues and directional illumination.

Journal Article Proceedings. Biological sciences · March 2016 Humans use shading as a cue to three-dimensional form by combining low-level information about light intensity with high-level knowledge about objects and the environment. Here, we examine how cuttlefish Sepia officinalis respond to light and shadow to sha ... Full text Cite

Do warning signals exploit an evolutionary constraint on insect visual acuity?

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2016 Link to item Cite

Visual acuity in fish: the effects of eye morphology, environment, and ecology

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2016 Link to item Cite

Spectral sensitivity, spatial resolution and temporal resolution and their implications for conspecific signalling in cleaner shrimp.

Journal Article The Journal of experimental biology · February 2016 Cleaner shrimp (Decapoda) regularly interact with conspecifics and client reef fish, both of which appear colourful and finely patterned to human observers. However, whether cleaner shrimp can perceive the colour patterns of conspecifics and clients is unk ... Full text Open Access Cite

Aposematic signals in North American black widows are more conspicuous to predators than to prey

Journal Article Behavioral Ecology · January 1, 2016 The iconic red hourglass of the black widow spiders (genus Latrodectus) is traditionally considered an aposematic signal, yet experimental evidence is lacking. Here, we present data that suggest that black widow coloration may have evolved to be an aposema ... Full text Cite

Identification and Ultrastructural Characterization of a Novel Nuclear Degradation Complex in Differentiating Lens Fiber Cells.

Journal Article PloS one · January 2016 An unresolved issue in structural biology is how the encapsulated lens removes membranous organelles to carry out its role as a transparent optical element. In this ultrastructural study, we establish a mechanism for nuclear elimination in the developing c ... Full text Cite

Freezing behaviour facilitates bioelectric crypsis in cuttlefish faced with predation risk.

Journal Article Proceedings. Biological sciences · December 2015 Cephalopods, and in particular the cuttlefish Sepia officinalis, are common models for studies of camouflage and predator avoidance behaviour. Preventing detection by predators is especially important to this group of animals, most of which are soft-bodied ... Full text Open Access Cite

Immunological dependence of plant-dwelling animals on the medicinal properties of their plant substrates: a preliminary test of a novel evolutionary hypothesis

Journal Article Arthropod-Plant Interactions · October 14, 2015 We present preliminary evidence for a novel evolutionary hypothesis, i.e., that animals living on plants high in antimicrobial secondary metabolites could, via drift or selection, evolve weakened immune defenses and an immunological dependence on the antim ... Full text Cite

Visual mutual assessment of size in male Lyssomanes viridis jumping spider contests

Journal Article Behavioral Ecology · February 11, 2015 Numerous animals are known to assess the resource holding potential of their opponents using conventional signals and other correlates of resource holding potential. Although body and weapon size generally correlate with resource holding potential and are ... Full text Cite

A unique apposition compound eye in the mesopelagic hyperiid amphipod Paraphronima gracilis.

Journal Article Current biology : CB · February 2015 The mesopelagic habitat is a vast space that lacks physical landmarks and is structured by depth, light penetration, and horizontal currents. Solar illumination is visible in the upper 1,000 m of the ocean, becoming dimmer and spectrally filtered with dept ... Full text Cite

Downwelling spectral irradiance during evening twilight as a function of the lunar phase.

Journal Article Applied optics · February 2015 We measured downwelling spectral vector irradiance (from 350 to 800 nm) during evening civil and nautical twilight (solar elevation down to -12°). Nine sets of measurements were taken to cover the first half of the lunar cycle (from the new to full moon) a ... Full text Cite

Cuttlefish Sepia officinalis Preferentially Respond to Bottom Rather than Side Stimuli When Not Allowed Adjacent to Tank Walls.

Journal Article PloS one · January 2015 Cuttlefish are cephalopods capable of rapid camouflage responses to visual stimuli. However, it is not always clear to what these animals are responding. Previous studies have found cuttlefish to be more responsive to lateral stimuli rather than substrate. ... Full text Cite

A dynamic broadband reflector built from microscopic silica spheres in the 'disco' clam Ctenoides ales.

Journal Article Journal of the Royal Society, Interface · September 2014 The 'disco' or 'electric' clam Ctenoides ales (Limidae) is the only species of bivalve known to have a behaviourally mediated photic display. This display is so vivid that it has been repeatedly confused for bioluminescence, but it is actually the result o ... Full text Cite

Competition for hummingbird pollination shapes flower color variation in Andean solanaceae.

Journal Article Evolution; international journal of organic evolution · August 2014 One classic explanation for the remarkable diversity of flower colors across angiosperms involves evolutionary shifts among different types of pollinators with different color preferences. However, the pollinator shift model fails to account for the many e ... Full text Cite

Simplifying numerical ray tracing for characterization of optical systems.

Journal Article Applied optics · July 2014 Ray tracing, a computational method for tracing the trajectories of rays of light through matter, is often used to characterize mechanical or biological visual systems with aberrations that are larger than the effect of diffraction inherent in the system. ... Full text Cite

Psychophysics and the evolution of behavior.

Journal Article Trends in ecology & evolution · May 2014 Sensory information allows animals to interpret their environment and make decisions. The ways in which animals perceive and measure stimuli from the social and physical environment guide nearly every decision they make. Thus, sensory perception and associ ... Full text Cite

Computational visual ecology in the pelagic realm.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · January 2014 Visual performance and visual interactions in pelagic animals are notoriously hard to investigate because of our restricted access to the habitat. The pelagic visual world is also dramatically different from benthic or terrestrial habitats, and our intuiti ... Full text Cite

Bioelectric crypsis in cephalopods reduces detection by shark predators

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · January 1, 2014 Link to item Cite

Clearly camouflaged: muscle architecture in transparent shrimp

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · January 1, 2014 Link to item Cite

The asymmetry of the underwater horizontal light field and its implications for mirror-based camouflage in silvery pelagic fish

Journal Article Limnology and Oceanography · January 1, 2014 Many pelagic species, particularly teleost fish, have silvered lateral surfaces that are thought to primarily serve as a form of camouflage. The underlying argument is that the underwater light field is cylindrically symmetrical around the vertical axis; t ... Full text Cite

Hide and seek in the open sea: pelagic camouflage and visual countermeasures.

Journal Article Annual review of marine science · January 2014 Camouflage is exceptionally challenging in pelagic environments because of their featureless nature. Thus, it is perhaps no surprise that pelagic species have evolved highly sophisticated cryptic strategies, three of which-transparency, mirrors, and counte ... Full text Cite

Ultrastructural analysis of the human lens fiber cell remodeling zone and the initiation of cellular compaction.

Journal Article Exp Eye Res · November 2013 The purpose is to determine the nature of the cellular rearrangements occurring through the remodeling zone (RZ) in human donor lenses, identified previously by confocal microscopy to be about 100 μm from the capsule. Human donor lenses were fixed with 10% ... Full text Link to item Cite

Eavesdropping on visual secrets

Journal Article Evolutionary Ecology · November 1, 2013 Private communication may benefit signalers by reducing the costs imposed by potential eavesdroppers such as parasites, predators, prey, or rivals. It is likely that private communication channels are influenced by the evolution of signalers, intended rece ... Full text Cite

Vision and the light environment.

Journal Article Current biology : CB · November 2013 Full text Cite

Visual acuity in pelagic fishes and mollusks.

Journal Article Vision research · November 2013 In the sea, visual scenes change dramatically with depth. At shallow and moderate depths (<1,000 m), there is enough light for animals to see the surfaces and shapes of prey, predators, and conspecifics. This changes below 1,000 m, where no downwelling day ... Full text Cite

Autophagy and mitophagy participate in ocular lens organelle degradation.

Journal Article Exp Eye Res · November 2013 The eye lens consists of a layer of epithelial cells that overlay a series of differentiating fiber cells that upon maturation lose their mitochondria, nuclei and other organelles. Lens transparency relies on the metabolic function of mitochondria containe ... Full text Link to item Cite

The giant eyes of giant squid are indeed unexpectedly large, but not if used for spotting sperm whales.

Journal Article BMC evolutionary biology · September 2013 BackgroundWe recently reported (Curr Biol 22:683-688, 2012) that the eyes of giant and colossal squid can grow to three times the diameter of the eyes of any other animal, including large fishes and whales. As an explanation to this extreme absolu ... Full text Cite

Fiber Cell Compaction in Adult Human Lenses Begins Near the Remodeling Zone in the Outer Cortex

Conference INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE · June 1, 2013 Link to item Cite

Pheromones exert top-down effects on visual recognition in the jumping spider Lyssomanes viridis.

Journal Article The Journal of experimental biology · May 2013 In diverse and productive habitats, predaceous arthropods are expected to frequently encounter dangerous conspecifics and heterospecifics. This should make quick and accurate discriminations between species and sexes adaptive. By simultaneously sampling bo ... Full text Cite

Visual acuity in deep-sea fish and mollusks

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · April 1, 2013 Link to item Cite

Why do giant squid have giant eyes?

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · April 1, 2013 Link to item Cite

Simple fixation and storage protocol for preserving the internal structure of intact human donor lenses and extracted human nuclear cataract specimens.

Journal Article Mol Vis · 2013 PURPOSE: Increased use of phacoemulsification procedures for cataract surgeries has resulted in a dramatic decrease in the availability of cataractous nuclear specimens for basic research into the mechanism of human cataract formation. To overcome such dif ... Link to item Cite

A novel method for comparative analysis of retinal specialization traits from topographic maps.

Journal Article Journal of vision · November 2012 Vertebrates possess different types of retinal specializations that vary in number, size, shape, and position in the retina. This diversity in retinal configuration has been revealed through topographic maps, which show variations in neuron density across ... Full text Cite

Light and vision in the deep-sea benthos: I. Bioluminescence at 500-1000 m depth in the Bahamian islands.

Journal Article The Journal of experimental biology · October 2012 Bioluminescence is common and well studied in mesopelagic species. However, the extent of bioluminescence in benthic sites of similar depths is far less studied, although the relatively large eyes of benthic fish, crustaceans and cephalopods at bathyal dep ... Full text Cite

Light and vision in the deep-sea benthos: II. Vision in deep-sea crustaceans.

Journal Article The Journal of experimental biology · October 2012 Using new collecting techniques with the Johnson-Sea-Link submersible, eight species of deep-sea benthic crustaceans were collected with intact visual systems. Their spectral sensitivities and temporal resolutions were determined shipboard using electroret ... Full text Cite

Electron tomography of fiber cell cytoplasm and dense cores of multilamellar bodies from human age-related nuclear cataracts.

Journal Article Exp Eye Res · August 2012 Human nuclear cataract formation is a multi-factorial disease with contributions to light scattering from many cellular sources that change their scattering properties over decades. The aging process produces aggregation of cytoplasmic crystallin proteins, ... Full text Link to item Cite

The male blue crab, Callinectes sapidus, uses both chromatic and achromatic cues during mate choice.

Journal Article The Journal of experimental biology · April 2012 In the blue crab, Callinectes sapidus, claw color varies by sex, sexual maturity and individual. Males rely in part on color cues to select appropriate mates, and these chromatic cues may be perceived through an opponent interaction between two photorecept ... Full text Cite

A unique advantage for giant eyes in giant squid.

Journal Article Current biology : CB · April 2012 Giant and colossal deep-sea squid (Architeuthis and Mesonychoteuthis) have the largest eyes in the animal kingdom [1, 2], but there is no explanation for why they would need eyes that are nearly three times the diameter of those of any other extant animal. ... Full text Cite

The black widow's hourglass: a covert aposematic signal?

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · April 1, 2012 Link to item Cite

Weaponry, color, and contest success in the jumping spider Lyssomanes viridis.

Journal Article Behavioural processes · March 2012 Weaponry and color badges are commonly theorized to function as visual signals of aggressiveness or fighting ability. However, few studies have supported a signaling function of weaponry, and the role of color in invertebrate competitive interactions remai ... Full text Cite

The optics of life: A biologist's guide to light in nature

Journal Article The Optics of Life: A Biologist's Guide to Light in Nature · January 19, 2012 Optics--a field of physics focusing on the study of light--is also central to many areas of biology, including vision, ecology, botany, animal behavior, neurobiology, and molecular biology.The Optics of Lifeintroduces the fundamentals of optics to biologis ... Cite

Are all vertebrate retinas configured the same? Implications for the evolution of acute vision.

Journal Article Proceedings of the Royal Society of London, Series B · 2012 Cite

Eavesdropping on visual secrets

Journal Article Evolutionary Ecology · 2012 Cite

Autophagy and Mitophagy in the Ocular Lens

Journal Article Journal of Cell Science · 2012 Cite

Anything that involves a photon and an animal.

Journal Article Current biology : CB · January 2012 Full text Cite

Mesopelagic cephalopods switch between transparency and pigmentation to optimize camouflage in the deep.

Journal Article Current biology : CB · November 2011 Animals in the lower mesopelagic zone (600-1,000 m depth) of the oceans have converged on two major strategies for camouflage: transparency and red or black pigmentation [1]. Transparency conveys excellent camouflage under ambient light conditions, greatly ... Full text Cite

A highly distributed Bragg stack with unique geometry provides effective camouflage for Loliginid squid eyes.

Journal Article Journal of the Royal Society, Interface · October 2011 Cephalopods possess a sophisticated array of mechanisms to achieve camouflage in dynamic underwater environments. While active mechanisms such as chromatophore patterning and body posturing are well known, passive mechanisms such as manipulating light with ... Full text Cite

Effects of molting on the visual acuity of the blue crab, Callinectes sapidus.

Journal Article The Journal of experimental biology · September 2011 In crustaceans with compound eyes, the corneal lens of each facet is part of the exoskeleton and thus shed during molting. Here we used an optomotor assay to evaluate the impact of molting on visual acuity (as measured by the minimum resolvable angle, α(mi ... Full text Cite

A chiton uses aragonite lenses to form images.

Journal Article Current biology : CB · April 2011 Hundreds of ocelli are embedded in the dorsal shell plates of certain chitons. These ocelli each contain a pigment layer, retina, and lens, but it is unknown whether they provide chitons with spatial vision. It is also unclear whether chiton lenses are mad ... Full text Cite

Twilight spectral dynamics and the coral reef invertebrate spawning response.

Journal Article The Journal of experimental biology · March 2011 There are dramatic and physiologically relevant changes in both skylight color and intensity during evening twilight as the pathlength of direct sunlight through the atmosphere increases, ozone increasingly absorbs long wavelengths and skylight becomes inc ... Full text Cite

The effects of salinity and temperature on the transparency of the grass shrimp Palaemonetes pugio.

Journal Article The Journal of experimental biology · March 2011 Transparency is an effective form of camouflage, but it must be present throughout the entire volume of an animal to succeed. Certain environmental stressors may cause physiological responses that increase internal light scattering, making tissue less tran ... Full text Cite

Underwater linear polarization: physical limitations to biological functions.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · March 2011 Polarization sensitivity is documented in a range of marine animals. The variety of tasks for which animals can use this sensitivity, and the range over which they do so, are confined by the visual systems of these animals and by the propagation of the pol ... Full text Cite

Polarization sensitivity as a contrast enhancer in pelagic predators: lessons from in situ polarization imaging of transparent zooplankton.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · March 2011 Because light in the pelagic environment is partially polarized, it has been suggested that the polarization sensitivity found in certain pelagic species may serve to enhance the contrast of their transparent zooplankton prey. We examined its potential dur ... Full text Cite

Seeing through rocks: Chitons use calcium carbonate lenses to form images

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · March 1, 2011 Link to item Cite

Spectral sensitivity of the concave mirror eyes of scallops: potential influences of habitat, self-screening and longitudinal chromatic aberration.

Journal Article The Journal of experimental biology · February 2011 Scallop eyes contain two retinas, one proximal and one distal. Molecular evidence suggests that each retina expresses a different visual pigment. To test whether these retinas have different spectral sensitivities, we used microspectrophotometry to measure ... Full text Cite

Camouflage in marine fish

Chapter · January 1, 2011 When we enter the marine environment as divers, snorkellers or even as television viewers, two things are immediately notable. We are supported by the water (or possibly armchair) ‘flying’ through a three-dimensional world, and we can't see very far. The l ... Full text Cite

The function of male-male threat displays in the jumping spider Lyssomanes viridis

Journal Article Behavioural Processes (online for now) · 2011 Cite

Multilamellar spherical particles as potential sources of excessive light scattering in human age-related nuclear cataracts.

Journal Article Exp Eye Res · December 2010 The goal of this project was to determine the relative refractive index (RI) of the interior of multilamellar bodies (MLBs) compared to the adjacent cytoplasm within human nuclear fiber cells. MLBs have been characterized previously as 1-4 μm diameter sphe ... Full text Link to item Cite

Spatial vision in the purple sea urchin Strongylocentrotus purpuratus (Echinoidea).

Journal Article The Journal of experimental biology · January 2010 Recent evidence that echinoids of the genus Echinometra have moderate visual acuity that appears to be mediated by their spines screening off-axis light suggests that the urchin Strongylocentrotus purpuratus, with its higher spine density, may have even mo ... Full text Open Access Cite

The importance of color in mate choice of the blue crab Callinectes sapidus.

Journal Article The Journal of experimental biology · November 2009 Visual displays often play a large role in animal communication, particularly in sexual interactions. The blue crab Callinectes sapidus is both colorful and highly visually responsive, yet almost all studies of their courtship have focused on chemical cues ... Full text Cite

Patterns of S-crystallin evolution are correlated with optical acuity in cephalopods

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · February 1, 2009 Link to item Cite

An inner ear magneto-receptor?

Journal Article Physics Today · February 1, 2009 Full text Cite

The optics and evolution of scallop eyes

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · February 1, 2009 Link to item Cite

Light, Biological Receptors

Chapter · January 1, 2009 Biological receptors used to detect underwater light vary in structure, from simple clusters of cells that only detect light intensity to complex organs that form detailed images. While most aquatic organisms perceive some portion of the visible spectrum, ... Full text Cite

Comparative morphology of the concave mirror eyes of scallops (Pectinoidea)

Journal Article American Malacological Bulletin · December 29, 2008 The unique, double-retina, concave mirror eyes of scallops are abundant along the valve mantle margins. Scallops have the most acute vision among the bivalve molluscs, but little is known about how eyes vary between scallop species. We examined eye morphol ... Full text Cite

Giant deep-sea protist produces bilaterian-like traces.

Journal Article Current biology : CB · December 2008 One of the strongest paleontological arguments in favor of the origin of bilaterally symmetrical animals (Bilateria) prior to their obvious and explosive appearance in the fossil record in the early Cambrian, 542 million years ago, is the occurrence of tra ... Full text Cite

Ultrastructural analysis of damage to nuclear fiber cell membranes in advanced age-related cataracts from India.

Journal Article Exp Eye Res · August 2008 The primary goal was to characterize the structural alterations that occur at the fiber cell interfaces in nuclei of fully opaque cataracts removed by extracapsular cataract surgery in India. The dark yellow to brunescent nuclei, ages 38-78 years, were pro ... Full text Link to item Cite

Scallops visually respond to the size and speed of virtual particles.

Journal Article The Journal of experimental biology · July 2008 The unique eyes of scallops are abundant along the right and left valve mantle margins. These eyes form images by reflection off a concave spherical mirror, and give scallops an angular resolution of around 2 degrees , far better than the 13-40 degrees ang ... Full text Cite

Mie light scattering calculations for an Indian age-related nuclear cataract with a high density of multilamellar bodies.

Journal Article Mol Vis · March 24, 2008 PURPOSE: Multilamellar bodies (MLBs) are lipid-coated spheres (1-4 microm in diameter) found with greater frequency in the nuclear region of human age-related cataracts compared with human transparent lenses. Mie light scattering calculations have demonstr ... Link to item Cite

Magnetoreception in animals

Journal Article Physics Today · March 11, 2008 Like the theory of plate tectonics, the idea that animals can detect Earth's magnetic field has traveled the path from ridicule to well-established fact in little more than one generation. Dozens of experiments have now shown that diverse animal species, r ... Full text Cite

Analysis of nuclear fiber cell cytoplasmic texture in advanced cataractous lenses from Indian subjects using Debye-Bueche theory.

Journal Article Exp Eye Res · February 2008 Alterations in ultrastructural features of the lens fiber cells lead to scattering and opacity typical of cataracts. The organelle-free cytoplasm of the lens nuclear fiber cell is one such component that contains vital information about the packing and org ... Full text Link to item Cite

Does new technology inspire new directions? Examples drawn from pelagic visual ecology.

Journal Article Integrative and comparative biology · December 2007 Oceanography has seen the recent development of many new tools and techniques. The subfield of pelagic visual ecology in particular has benefited from the development of more reliable, portable, and economic tools and techniques that can be taken to sea in ... Full text Cite

Comparative visual acuity of coleoid cephalopods.

Journal Article Integrative and comparative biology · December 2007 The pelagic realm of the ocean is characterized by extremely clear water and a lack of surfaces. Adaptations to the visual ecology of this environment include transparency, fluorescence, bioluminescence, and deep red or black pigmentation. While the signal ... Full text Cite

Light scattering by selected zooplankton from the Gulf of Aqaba.

Journal Article The Journal of experimental biology · November 2007 Light scattering by zooplankton was investigated as a major factor undermining transparency camouflage in these pelagic animals. Zooplankton of differing transparencies--including the hyperiid amphipod Anchylomera blossevillei, an unknown gammarid amphipod ... Full text Cite

A field test of the Hamilton-Zuk hypothesis in the Trinidadian guppy (Poecilia reticulata)

Journal Article Behavioral Ecology and Sociobiology · October 1, 2007 The Hamilton-Zuk hypothesis proposes that females prefer male secondary sexual traits because they are honest indicators of parasite resistance. Despite the attention that this hypothesis has received, its role in sexual selection remains equivocal. This s ... Full text Cite

Light-dependent magnetoreception: quantum catches and opponency mechanisms of possible photosensitive molecules.

Journal Article The Journal of experimental biology · September 2007 Dozens of experiments on magnetosensitive, migratory birds have shown that their magnetic orientation behavior depends on the spectrum of light under which they are tested. However, it is not certain whether this is due to a direct effect on the magnetorec ... Full text Cite

Evolution of graded refractive index in squid lenses.

Journal Article Journal of the Royal Society, Interface · August 2007 A lens with a graded refractive index is required for vision in aquatic animals with camera-type eyes. This optical design entails a radial gradient of protein density, with low density in external layers and high density in internal layers. To maintain th ... Full text Cite

Comparative visual acuity of coleoid cephalopods

Journal Article Integrative and Comparative Biology · 2007 Cite

Predicted light scattering from particles observed in human age-related nuclear cataracts using mie scattering theory.

Journal Article Invest Ophthalmol Vis Sci · January 2007 PURPOSE: To employ Mie scattering theory to predict the light-scattering from micrometer-sized particles surrounded by lipid shells, called multilamellar bodies (MLBs), reported in human age-related nuclear cataracts. METHODS: Mie scattering theory is appl ... Full text Link to item Cite

Scallops respond to simulated particles in flow

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2006 Link to item Cite

Visual Ecology on the high seas

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2006 Link to item Cite

Evolution of high-acuity vision in coleoid cephalopods

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2006 Link to item Cite

Ultraviolet vision and foraging in juvenile bluegill (Lepomis macrochirus)

Journal Article Canadian Journal of Fisheries and Aquatic Sciences · October 1, 2006 Ultraviolet (UV) photoreceptors have been reported in a wide variety of freshwater and marine organisms, suggesting that UV vision is prominent in aquatic ecosystems. However, its adaptive significance remains speculative. The present study tested whether ... Full text Cite

Polarization sensitivity in the red swamp crayfish Procambarus clarkii enhances the detection of moving transparent objects.

Journal Article The Journal of experimental biology · May 2006 We tested the hypothesis that polarization sensitivity enhances the detection of moving, transparent objects by examining the escape response of the red swamp crayfish (Procambarus clarkii Girard) from a visual threat. A transparent, birefringent target tr ... Full text Cite

Crepuscular and nocturnal illumination and its effects on color perception by the nocturnal hawkmoth Deilephila elpenor.

Journal Article The Journal of experimental biology · March 2006 Recent studies have shown that certain nocturnal insect and vertebrate species have true color vision under nocturnal illumination. Thus, their vision is potentially affected by changes in the spectral quality of twilight and nocturnal illumination, due to ... Full text Cite

UV vision and the Feeding Ecology of Juvenile Bluegill Sunfish, Lepomis machrochirus.

Journal Article Canadian Journal of Fisheries and Aquatic Sciences · 2006 Cite

Detection of polarized light by loggerhead sea turtles (Caretta caretta)

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2005 Link to item Cite

Polarization vision in crayfish enhances motion detection

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2005 Link to item Cite

Wavelength-dependent phototaxis as a depth regulating mechanism in a ctenophore

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2005 Link to item Cite

The physics and neurobiology of magnetoreception.

Journal Article Nature reviews. Neuroscience · September 2005 Diverse animals can detect magnetic fields but little is known about how they do so. Three main hypotheses of magnetic field perception have been proposed. Electrosensitive marine fish might detect the Earth's field through electromagnetic induction, but d ... Full text Cite

The red and the black: bioluminescence and the color of animals in the deep sea.

Journal Article Integrative and comparative biology · April 2005 The colors of deep-sea species are generally assumed to be cryptic, but it is not known how cryptic they are and under what conditions. This study measured the color of approximately 70 deep-sea species, both pelagic and benthic, and compared the results w ... Full text Cite

Sensory biology: Linking the internal and external ecologies of marine organisms

Journal Article Marine Ecology Progress Series · February 18, 2005 Full text Cite

Visual ecology on the high seas

Journal Article MARINE ECOLOGY PROGRESS SERIES · January 1, 2005 Link to item Cite

The red and the black: Bioluminescence and the color of animals in the deep sea

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2004 Link to item Cite

Spatial vision in the echinoid genus Echinometra

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2004 Link to item Cite

Evolution of complex optics in squid lenses

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2004 Link to item Cite

Cataract formation in a strain of rats selected for high oxidative stress.

Journal Article Exp Eye Res · November 2004 The primary purpose of this study was to define the clinical and morphological features of cataractogenesis in the OXYS strain of rats that generate excess reactive oxygen species. Rats were sequentially examined from birth to the development of mature cat ... Full text Link to item Cite

Spatial vision in the echinoid genus Echinometra.

Journal Article The Journal of experimental biology · November 2004 Although eyes are generally considered necessary for image resolution, a diffuse photoreceptive system with directional sensitivity may also have this ability. Two species of the echinoid genus Echinometra were tested for spatial vision by examining their ... Full text Cite

Distribution, spherical structure and predicted Mie scattering of multilamellar bodies in human age-related nuclear cataracts.

Journal Article Exp Eye Res · October 2004 PURPOSE: To characterize multilamellar bodies (MLBs), determine their distribution along the optic axis and predict their potential Mie scattering within human age-related nuclear cataracts. Previous studies restricted to the equatorial plane have shown th ... Full text Link to item Cite

Propagation and perception of bioluminescence: factors affecting counterillumination as a cryptic strategy.

Journal Article The Biological bulletin · August 2004 Many deep-sea species, particularly crustaceans, cephalopods, and fish, use photophores to illuminate their ventral surfaces and thus disguise their silhouettes from predators viewing them from below. This strategy has several potential limitations, two of ... Full text Cite

Mie light scattering analysis of human age-related nuclear cataracts

Conference INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE · April 1, 2004 Link to item Cite

Shedding light on light in the ocean

Journal Article Oceanus · 2004 Cite

Biological optical instruments in the deep sea

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2003 Link to item Cite

Lifting the cloak of invisibility: the effects of changing optical conditions on pelagic crypsis.

Journal Article Integrative and comparative biology · August 2003 While transparency, cryptic coloration, and counterillumination are all highly successful cryptic strategies for pelagic species, they become less effective when confronted with varying optical conditions. Transparent species are susceptible to detection b ... Full text Cite

Responses of hatchling sea turtles to rotational displacements

Journal Article Journal of Experimental Marine Biology and Ecology · March 25, 2003 After emerging from underground nests, sea turtle hatchlings migrate through the surf zone and out to the open ocean. During this migration, both waves and water currents can disrupt hatchling orientation by unpredictably rotating the turtles away from the ... Full text Cite

Cryptic coloration and mirrored sides as camouflage strategies in near-surface pelagic habitats: Implications for foraging and predator avoidance

Journal Article Limnology and Oceanography · January 1, 2003 Mirrored and colored surfaces are common adaptations for crypsis in pelagic habitats. Although highly successful when optimized for a particular situation, either may become less successful if it is then viewed in a different situation. In this study we ex ... Full text Cite

Minors or colors? Successful fashions for crypsis in the pelagic realm.

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2002 Link to item Cite

Bio-optics and visual ecology of Heliconius color patterns.

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · December 1, 2002 Link to item Cite

Cryptic and conspicuous coloration in the pelagic environment.

Journal Article Proceedings. Biological sciences · February 2002 Despite the importance of cryptic and conspicuous coloration in pelagic ecosystems, few researchers have investigated the optimal reflectance spectra for either trait. In this study, the underwater radiance distribution in tropical oceanic water was modell ... Full text Cite

Hidden in plain sight: the ecology and physiology of organismal transparency.

Journal Article The Biological bulletin · December 2001 Despite the prevalence and importance of transparency in organisms, particularly pelagic species, it is a poorly understood characteristic. This article reviews the current state of knowledge on the distribution, ecology, and physical basis of biological t ... Full text Cite

Ultraviolet absorption in transparent zooplankton and its implications for depth distribution and visual predation

Journal Article Marine Biology · January 1, 2001 The use of transparency as camouflage in the epipelagic realm is complicated by the presence of ultraviolet radiation, because the presence of UV-protective pigments decreases UV transparency and may reveal transparent zooplankton to predators and prey wit ... Full text Cite

The neurobiology of magnetoreception in vertebrate animals.

Journal Article Trends in neurosciences · April 2000 Diverse vertebrate animals can sense the earth's magnetic field, but little is known about the physiological mechanisms that underlie this sensory ability. Three major hypotheses of magnetic-field detection have been proposed. Electrosensitive marine fish ... Full text Cite

Transparent animals.

Journal Article Scientific American · February 2000 Full text Cite

3D spatial point patterns of bioluminescent plankton: A map of the 'mine field'

Journal Article Journal of Plankton Research · January 1, 2000 As the open ocean environment lacks points of refuge from visual predators, it has favored the evolution of extraordinary adaptations for optical concealment, such as vertical migration, transparency and counterillumination. Bioluminescent plankton, which ... Full text Cite

Shade-seeking behaviour under polarized light by the brittlestar Ophioderma brevispinum (Echinodermata: Ophiuroidea)

Journal Article Journal of the Marine Biological Association of the United Kingdom · August 1, 1999 The effect of polarized light on the shade-seeking behaviour of the ophiuroid Ophioderma brevispinum was investigated at the Keys Marine Laboratory, Long Key, Florida, USA. Animals were collected and placed in a partially shaded arena. When the arena was i ... Full text Cite

Thin layers of bioluminescent copepods found at density discontinuities in the water column

Journal Article Marine Biology · August 1, 1999 To learn how organisms apportion space in the open ocean, biological oceanographers have sought to improve temporal and spatial resolution of ocean sampling systems. Their objectives are to simultaneously measure physical, chemical and biological structure ... Full text Cite

The physical basis of transparency in biological tissue: Ultrastructure and the minimization of light scattering

Journal Article Journal of Theoretical Biology · July 21, 1999 In the open ocean, many animals are highly transparent, some achieving near invisibility. However, little is known about how this transparency is attained. The effects of cellular ultrastructure on tissue transparency were mathematically modeled. Given a s ... Full text Cite

Light-emitting suckers in an octopus

Journal Article Nature · March 11, 1999 Full text Cite

Bioluminescence in the deep-sea cirrate octopod Stauroteuthis syrtensis verrill (Mollusca: Cephalopoda)

Journal Article Biological Bulletin · January 1, 1999 The emission of blue-green bioluminescence (λ(max) = 470 nm) was observed from sucker-like structures arranged along the length of the arms of the cirrate octopod Stauroteuthis syrtensis. Individual photophores either glowed dimly and continuously or flash ... Full text Cite

Transparency and visibility of gelatinous zooplankton from the Northwestern Atlantic and Gulf of Mexico

Journal Article Biological Bulletin · January 1, 1998 Transparency measurements (at 400 to 700 nm) were made on living specimens of 29 common species of gelatinous zooplankton from the Northwestern Atlantic Ocean and Gulf of Mexico. Percent transparency ranged from 91% for the hydromedusa Sibogota typa to 0.5 ... Full text Cite

Damage due to solar ultraviolet radiation in the brittlestar Ophioderma brevispinum (Echinodermata: Ophiuroidea)

Journal Article Journal of the Marine Biological Association of the United Kingdom · January 1, 1998 Many morphological, chemical, and behavioural characteristics of echinoderms have been implicated as defences against ultraviolet light, though no studies have investigated whether adult echinoderms are damaged by this form of radiation. This study tests w ... Full text Cite

Identification and localization of a possible rhodopsin in the echinoderms Asterias forbesi (Asteroidea) and Ophioderma brevispinum (Ophiuroidea).

Journal Article The Biological bulletin · August 1997 Protein extracts of optic cushion tissue from the asteroid Asterias forbesi and arm tissue from the ophiuroid Ophioderma brevispinum were subjected to Western blot analysis. Both tissues contain a membrane-associated protein that reacts with two monoclonal ... Full text Cite

Extraocular sensitivity to polarized light in an echinoderm.

Journal Article The Journal of experimental biology · October 1994 This study tests the hypotheses that the birefringent calcite and stereom structure of the brittlestar (Ophiuroidea, Echinodermata) endoskeleton polarizes light and that certain brittlestars respond to polarized light. The first hypothesis was tested in Op ... Full text Cite

Intramuscular crossed connective tissue fibres: skeletal support in the lateral fins of squid and cuttlefish (Mollusca: Cephalopoda)

Journal Article Journal of Zoology · January 1, 1993 The lateral fins of cuttlefish and squid were modelled to test the hypothesis that an array of crossed connective tissue fibres embedded within the musculature of the fins provides the support required for bending and to evaluate the role of the connective ... Full text Cite

Coevolution to the edge of chaos: coupled fitness landscapes, poised states, and coevolutionary avalanches.

Journal Article Journal of theoretical biology · April 1991 We introduce a broadened framework to study aspects of coevolution based on the NK class of statistical models of rugged fitness landscapes. In these models the fitness contribution of each of N genes in a genotype depends epistatically on K other genes. I ... Full text Cite