Meeting Abstract

P1.47  Saturday, Jan. 4 15:30  Insights into the significance of epidermal club cell variation using a self-fertilizing hermaphroditic fish MARSON, KM*; EARLEY, RL; Univ. of Alabama; Univ. of Alabama krismars02@yahoo.com

Many fish species possess epidermal club cells (ECCs), which appear to serve the animal through supporting its immune system, enhancing resistance to parasitic infection and offering protection from UV exposure. Chemicals within the club cells, which are only released into the environment when the epidermis is damaged, also indicate predation events and cause conspecifics to freeze or flee. Recently, it has been shown that there is a great deal of within- and among-population variation in the number of ECCs, some of which remains even when animals are raised under common garden conditions. Interpretation of variation in the presence and adaptive value of ECCs is complicated by genetic variation within and among populations. Mangrove rivulus fish exist as self-fertilizing hermaphrodites and multiple unique isogenic strains exist within each population. They occur over a wide geographic range (northern Brazilian coast throughout the Caribbean to the Florida coasts) and in diverse microhabitats. This species thus offers an opportunity for examining the abundance of ECCs in relation to environmental and social conditions without the genetic noise unavoidable in most wild populations. Preliminary evidence supports the presence of epidermal club cells in this species. Previous evidence indicates that the number of ECCs increases as a function of population density due to the potential increase in exposure to pathogens and parasites. Extending from the fact that significant differences in our catch-per-effort exist between populations from the coasts of Belize and central Florida, we hypothesize that high-density populations originating in Belize will have a significantly greater number of ECCs than low-density populations originating along the central coast of Florida.