Meeting Abstract
The ‘disco’ clam Ctenoides ales (Limidae) is the only bivalve known to have a behaviorally mediated photic display. The flashing occurs on the mantle lip and is the result of light scattering by silica nanospheres. Ongoing studies suggest the flashing acts as an aposematic predator deterrent. The goal of this study was to investigate the evolution of the flashing display and to determine the genetic mechanism underlying the flashing. We generated a Bayesian Inference phylogeny using one nuclear (28S rRNA) and two mitochondrial (16S rRNA and COI) genes. Results reveal C. ales as the basal lineage in the Ctenoides genus, suggesting that evolution of flashing arose early when examining four Ctenoides species. Tissue-specific (mantle) RNAs were extracted from three Ctenoides species (C. ales, C. scaber, and C. mitis), and transcriptome libraries were sequenced. Future work will take a comparative transcriptomic approach to identify candidate genes for the flashing. In addition to the flashing display of C. ales, limids possess a wide array of defense mechanisms, including tentacle autotomy (Limaria), aposematism (Ctenoides), and escape swimming (Lima). Future work will expand the phylogeny in order to parse together morphology, habitat, and distribution to develop a complete understanding of the evolution of defenses within the Limidae.
