Vision in the Deep

During research cruises funded by the NOAA Ocean Exploration Program (Operation Deep-Scope 2005 and 2007), novel collecting techniques were used to collect live deep-sea benthic crustaceans. Collections were made from the HBOI Johnson-Sea-Link (JSL) submersible under red and orange illumination, making it possible to collect animals without blinding them. Shipboard measurements of spectral sensitivity and temporal resolution were made from the photoreceptors of the anomuran crabs, Gastroptychus spinifer, Eumunida picta, Munidopsis tridentata, the brachyuran crab, Bathynectes longispina,the decapod shrimp, Eugonatonotus crassus, and the isopod, Booralana tricarinata. The spectral sensitivity data indicate that all of these species have blue sensitive visual pigments, but G. spinifer also appears to possess a UV sensitive visual pigment. The temporal resolution of all these eyes is quite low, indicating that these photoreceptors have a long integration time. The temporal resolution of Booralana tricarinata, is so low that it is unlikely that this isopod could track any moving object. Rather, its photoreceptors appear to be designed for finding bioluminescence that glows rather than flashes, such as detritus covered with bioluminescent bacteria.