Meeting Abstract
Kryptolebias marmoratus is a quasi-amphibious species living in upper intertidal zones of mangrove swamps that is able to survive outside of water for many hours, and on rare occasions, weeks at a time. K. marmoratus is often found living in burrows of land crabs and feeds on insects both in and out of the water. As vision in air versus water is necessarily different due to the change in refractive index of the medium, we asked what simple visual cues were used by K. marmoratus when moving on land. We hypothesized that the fish might prefer dark areas, or might prefer structures. A shallow kiddie pool was painted to have one quarter black, while the other three were painted white. The black quarter and one white quarter were left devoid of structures; the remaining sections had pieces of white and black PVC pipe, respectively, placed in them. The location of the structures was randomized from trial to trial. The pool was lined with wetted bench liner paper to prevent the fish from desiccating. Individuals (n = 13 fish; n = 4 trials per fish) were placed under a cup in the center of the kiddie pool, and a Kodak PlaySport camera was placed above the pool to record each two minute trial of the fish voluntarily moving around. Overall, K. marmoratus spent more time in the sections with the presence of a PVC pipe compared to the empty sections. Interestingly, specimens spent more time in the white empty section compared to the black empty section, which was opposite of our prediction. Fish spent more time in the sections with the white PVC pipe compared to the black PVC pipe. These results suggest that K. marmoratus is able to see in air with enough acuity that it is able to choose destinations containing potential hiding structures.
