Meeting Abstract

P3.118  Sunday, Jan. 6  Density Estimates, Growth Patterns, and Diet of the California moray, Gymnothorax mordax, Around Catalina Island MEHTA, R/S; Univ. of California, Santa Cruz rsmehta1123@gmail.com

Documenting the trophic ecology, density, spatial distributions, and growth rates of top predators is essential to our understanding of community dynamics. Despite the probable importance of morays in structuring kelp forest dynamics no study has attempted to investigate the predatory habits, relative abundance, and growth patterns of the California moray, Gymnothorax mordax. Here, I propose to assess the potential importance of the California moray in structuring kelp forest communities by collecting basic biological data that is lacking for this apex predator such as density estimates, growth patterns, and diet. I used modified lobster traps to catch eels at 6 different sites along the west side of Catalina Island. Once captured, 8 morphological measures were recorded on each individual and morays were PIT tagged before release. At the end of August – early September,over 200 moray eels were captured along 1400 meters of rocky kelp forest habitat. Morays ranged from 10g to just over 5kg in mass. Morphological variables such as head length, vertical gape, and body width exhibited negative allometry with standard length. At smaller size ranges (20-60 cm in standard length) morays appear to increase their mass at a much faster rate while mass appears to slow down when individuals reach roughly 80 cm in total length. This slowing of mass with standard length may indicate that morays are reaching their maximum body size. Diet data from field observations suggest that the California moray has a more omnivorous feeding habit compared to other tropical moray species and consumes a variety of crabs and fish that inhabit the temperate kelp forest.