Visual Adaptations of Life History Stages of Ontogenetically Migrating Crustaceans
2007 The Society for Integrative and Comparative Biology Annual Meeting, Phoenix, AZ, January 3-7, 2007
Most deep-sea adult shrimps have superposition compound eyes, which are adapted to maximize sensitivity. However, the juveniles of some of these shrimps live shallower than the adults, a phenomenon called ontogenetic migration. It is hypothesized that the juveniles will have visual adaptations to the higher light environment present in shallower waters, including apposition optics, which are thought to maximize resolution while necessarily sacrificing sensitivity. In this study, juveniles and adults of several species of deep-sea crustaceans were examined. The ontogenetically migrating species Gnathophausia ingens, Oplophorus gracilirostris, and Systellaspis debilis were compared to Notostomus gibbosus, a decapod shrimp in which both the juveniles and adults live below 700 m depth. Preliminary evidence indicates that there are structural differences between the eyes of juvenile and adult ontogenetic migrators that indicate that the shallower dwelling juveniles are less sensitive to light than the deeper living adults. Juveniles of the species O. gracilirostris have apposition optics and screening pigments, adaptations for brightly lit environments, whereas the adults have superposition optics. Both juveniles and adults of N. gibbosus, the non-migrator, have superposition optics, suggesting that both life stages have adapted to the low irradiance present in the deep-sea environment.
Whitehill, Elizabeth A. G. and Frank, Tamara M., "Visual Adaptations of Life History Stages of Ontogenetically Migrating Crustaceans" (2007). Oceanography Faculty Proceedings, Presentations, Speeches, Lectures. 138.