Meeting Abstract

111.3  Sunday, Jan. 6  Metamorphosis of Crepidula larvae in response to varying conspecific densities and settlement cue concentrations CAHILL, AE; Stony Brook University acahill@life.bio.sunysb.edu

It is known that larvae of Crepidula spp., like many other marine invertebrate larvae, metamorphose in response to a cue from conspecific adults. However, the relationship between adult density and larval metamorphosis is not well-characterized in C. fornicata or C. plana. On Long Island, C. fornicata occurs at much higher densities than C. plana, which has a patchier habitat. C. fornicata may therefore be less sensitive to conspecific cue than C. plana. Here, I performed a bioassay using adult-conditioned water to examine metamorphosis in both Crepidula spp. in response to cue from conspecific and heterospecific adults. Because metamorphosis in still water rarely mimics field conditions, I varied adult density and measured settlement of C. fornicata larvae in the field. Larvae in both the lab and the field metamorphosed at higher rates with increasing adult density. These results indicate that recruitment in small populations of Crepidula may be limited by the ability of larvae to detect conspecific adults, which in turn has implications for population dynamics at range edges.