The “ventral organ” of Jasus paulensis (Crustacea, Decapoda)

Abstract

A "ventral organ" mainly made up of lipoprotein cells is observed in Jasus paulensis and all the Decapoda we have been studying. It is extensive during the early premolt stages because of the development of both number and size of cells. Sometimes, the presence of smaller finely granular cells is noted, chiefly in early premolt stages. Crystals are visible from stage D1' to stage D2 in extracellular spaces between the "adipocyte type cells." They are postulated to be calcium deposits. The "organ" contains many lipids; most of them are phospholipids (phosphatidyl-choline, phosphatidyl-ethanolamine) but a few are neutral fats. This "organ" seems to be only a preferential site for the accumulation of adipose tissues. The functions of this ventral tissue as well as those of the cyclic adipose tissue are discussed in relation to the storage of materials, synthesis of lipoproteins, and general metabolism in Crustacea.