Comparative visual acuity of coleoid cephalopods.

Journal Article (Journal Article)

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 signals that pelagic organisms send are increasingly well-understood, the optical capabilities of their viewers, especially for predators with camera-like vision such as fish and squid, are almost unknown. Aquatic camera-like vision is characterized by a spherical lens focusing an image on the retina. Here, we measured the resolving power of the lenses of eight species of pelagic cephalopods to obtain an approximation of their visual capabilities. We did this by focusing a standard resolution target through dissected lenses and calculating their modulation transfer functions. The modulation transfer function (MTF) is the single most complete expression of the resolving capabilities of a lens. Since the optical and retinal capabilities of an eye are generally well-matched, we considered our measurements of cephalopod lens MTF to be a good proxy for their visual capabilities in vivo. In general, squid have optical capabilities comparable to other organisms generally assumed to have good vision, such as fish and birds. Surprisingly, the optical capability of the eye of Vampyroteuthis infernalis rivals that of humans.

Full Text

Duke Authors

Cited Authors

  • Sweeney, AM; Haddock, SHD; Johnsen, S

Published Date

  • December 2007

Published In

Volume / Issue

  • 47 / 6

Start / End Page

  • 808 - 814

PubMed ID

  • 21669760

Electronic International Standard Serial Number (EISSN)

  • 1557-7023

International Standard Serial Number (ISSN)

  • 1540-7063

Digital Object Identifier (DOI)

  • 10.1093/icb/icm092


  • eng