Organization of optic lobes in a highly visual decapod.

JULIETA SZTARKER; DANIEL TOMSIC

Washington

Conferencia; Insect Vision: Cells, computation and behavior.; 2013

Janelia Farm Research Campus HHMI

Evolutionary relationships within Arthropoda, particularly between crustaceans and hexapods, are a subject of continuous debate. Remarkably, regardless of the interest in comparative studies of the eyes and nervous systems of arthropods, neuroanatomical work in crustaceans have not kept pace with the large amount of anatomical descriptions found in insects. Additionally, since crayfish has been the most studied crustacean, it is taken as a representative of the taxa. This is rather unfortunate since it has a relatively poor vision inhabiting turbid water and being active in dim light. As a consequence, the notion that decapods? visual system is rather simple when compared with insects emerged. However, crustaceans are vastly distributed and inhabit very different niches, including land, shallow and deep sea water, fresh water, and even deserts. Thus visual requirements/ attributes are expected to vary considerably within this group. We study the neuroanatomy of the optic lobes in a highly visual semiterrestrial crab Neohelice granulata (previously called Chasmagnathus granulatus) which lives in colonies, socially interacts, and is subject to predatory attacks by birds. At low tide it is a terrestrial forager, viewing in clear air, whereas during intermediate and high tide it lives in turbid water. By studying the composition of its visual neuropiles using classical anatomical techniques, we show that this crab possesses a complexity comparable to that of land insects.