Meeting Abstract

P2.107  Sunday, Jan. 5 15:30  Ink from longfin inshore squid, Doryteuthis pealeii, as a chemical defense against two predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis TOTTEMPUDI, M.*; LOVE-CHEZEM, T.; WOLFE, L.S.; DERBY, C.D.; Georgia State University, Atlanta, GA; Georgia State University, Atlanta, GA; Georgia State University, Atlanta, GA; Georgia State University, Atlanta, GA mtottempudi1@student.gsu.edu

Chemical defenses are used by many organisms to avoid being attacked or eaten by predators. An example is inking molluscs, including gastropods such as sea hares and cephalopods such as squid, cuttlefish, and octopus, which release a colored ink upon attack. Previous work showed that ink can protect molluscs through a combination of chemical, visual, and/or mechanical effects. In this study, we examined the effects of ink from longfin inshore squid, Doryteuthis pealeii, on the behavior of two species of predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis. Using a cloud assay, we found that ink from longfin inshore squid affected the approach phase of predation by summer flounder, primarily through its visual effects. Using a food assay, we found that the ink affected the consummatory and ingestive phase of predation of both sea catfish and summer flounder, through the ink’s chemical properties. Fractionation of ink showed that most of its deterrent chemical activity is associated with ink’s melanin granules, suggesting that either compounds adhering to these granules or melanin itself are most biologically active. This work provides the basis for a comparative approach to identify deterrent molecules from inking cephalopods and to examine neural mechanisms whereby these chemicals affect behavior of fish using the sea catfish as a chemosensory model.