Somatic and ovarian germinative components of the mangrove crab, Ucides cordatus Linnaeus, 1763 (Decapoda: Ocypodidae)

Abstract

The mangrove crab, Ucides cordatus, is submitted to intensive exploitation in North and Northeast Brazil, what may be leading to stock depletion and reduction of mean individual size. Thus, the knowledge of the histological and embryological structure of its reproductive organ is important to assist in the conservation management. This research work aims at studying details on the processes of formation of the germinatives and somatic cells, related to oogenesis and vitellogenesis in females, characterizing the different periods of gonadal development through histological and microscopy techniques. The crabs were collected monthly, during the period of November to May, and soon afterwards submitted to the ovary dissection. The germinative cells consisted of oogonia, pre-vitellogenic oocytes, vitellogenic oocytes, and mature oocytes. These sexual cells were always seen to be found together with somatic follicular, accessory cells. In the general organization of the ovary, the presence of lining, blood vessels, hemal sinuses and lumen was noticeable. The histochemical tests have shown the appearance of small yolk granules whose composition include proteins or lipids. In addition to those important germinative elements, the accessory cells participate actively in each stage of the ovarian development. Thus, it was evident that the process of oogenesis in females of the mangrove crab develops by stages and it is intrinsically connected to yolk formation during the germinative cells’ growth.