Visual orientation of the symbiotic snapping shrimp Synalpheus demani

Visual cues play an important role in crustacean shelter-seeking behavior. We hypothesize that Synalpheus demani, an obligate crinoid-dwelling snapping shrimp, uses visual cues in host location. We tested shrimp response to rectangular visual targets that subtended 10°, 30°, 90°, 180°, and 270°in a circular arena in background seawater and in seawater containing host odor. In background seawater, S. demani oriented to solid visual targets of 90°and larger, and avoided the 10°and 30°target. Orientation to targets is interpreted as refuge-seeking behavior. Avoidance is speculated as predator-avoidance behavior. Shrimp oriented to large visual targets in sea water and host odor. The presence of host odor altered avoidance responses of a significant number, but not all, shrimp to small targets. Host odor also increased shrimp activities in the arena. Synalpheus demani oriented to 90°patterned (vertical and horizontal stripes, and checker board) targets, but they did not orient to 270°patterned targets. This was interpreted as positive scototaxis, which is common in many crustaceans. Thus we conclude that visual orientation of S. demani is similar to that of free-living snapping shrimp. © 2005 Elsevier B.V. All rights reserved.

Duke Scholars

Author Daniel Rittschof Marine Science and Conservation