51-2 Friday, Jan. 5 10:30 - 10:45 Do (Eyeless) Sea Urchins Have Color Vision? NOTAR, JC*; JOHNSEN, S; Duke University; Duke University email@example.com
Sea urchins appear to have spatial vision, despite lacking both eyes and eye spots. While investigations of their visual acuity and sensitivity have taken place, color vision in sea urchins is an unexplored possibility. Purple sea urchins, Strongylocentrotus purpuratus, express at least five opsins and therefore possess a potential physiological mechanism for color vision. Urchins are dominant, benthic grazers in a variety of marine habitats, and it is possible they may use color to identify food sources. Additionally, many species are known to aggregate with conspecifics or heterospecifics, indicating color could be used for intra- and interspecies recognition. Behavioral assays to determine urchins’ reactions to stimuli of different color were conducted. Animals were placed in a round tank and allowed to choose between evenly spaced targets: multiple grey targets of various shades and one colored target. If urchins moved consistently toward or away from the colored target, and not a grey one of similar brightness, it indicated the ability to discriminate color. Results will be discussed.