Ocular structure of the Callinectes sapidus

Abstract

The crab Callinectes sapidus, inhabiting tropical and temperate coasts, in the waters of bays, coastal lagoons, estuaries and river mouths. They are omnivorous, benthic, opportunistic, active and voracious. It is suggested that the eyes of this species are of the overlapping type, as they are nocturnal organisms, which allows them to find food and a mate during this period. However, your eyes are subject to a water column and different salinity gradients, along with exposure to different intensities of moonlight. This study consisted of describing the internal structure of the eye of the Callinectes sapidus to determine if it corresponded to the appositional compound eye. The collection of organisms was carried out in Laguna de La Mancha, Actopan Veracruz, Mex., collecting 60 organisms, which were fixed in Bouin. Ocular tissue was submitted to histological techniques, stained with Hematoxylin & Eosin. As a result, it was found that each ommatidium is composed of four structures: cornea, lens, rhabdomyoma and basement membrane. The cornea is thin and in turn is divided into two layers. The lens, made up of four organized cells, in the cone shape. The rhabdomyoma is composed of seven long, longitudinally aligned rhabdomeric cells. The deep portion of the rhabdomyoma is associated with the basement membrane. The bundled nerve fiber endings for each rhabdomeric cell are distributed at this junction site of the rhabdomyobasal membrane. Conclusion: the structural organization of ommatidia of the Callinectes sapidus includes an eye of the overlapping type characteristic of nocturnal organisms.