FINE STRUCTURE AND SECRETORY ACTIVITY OF THE SPERMATHECA OF THE FRESHWATER CRAB PARATELPHUSA HYDRODROMOUS (CRUSTACEA : DECAPODA)

The multifibrilar musculature that encircles the spermathecal epithelium of Paratelphusa hydrodromous is composed of slow acting fibres characterized by the abundance of sarcoplasm, scarcity of myofibrils, lack of division of myofibrils into sacrcomeres, absence of T-system, poorly developed sarcoplasmic reticulum and sparseness in mitochondria. The secretory epithelium is composed of a single type of columnar cell with basally located multinucleolated nuclei. OctoberNovember (the pre-breeding season) is the period of synthesis of intrinsic secretion of the spermathecal epithelial cells. The mode of release of secretion is apocrine and occurs towards the end of the pre-breeding season.