Structure of the accessory glands and duplex of the internal male reproductive system of Calpodes ethlius (Hesperiidae, Lepidoptera)

Abstract

The paired accessory glands of Calpodes ethlius are long, blind tubes which open into the ductus ejaculatorius duplex (duplex) at a constriction. They are held closely together to each other by tracheoles. Combined light and electron microscopy suggests that there are at least six regions. These regions are identified by the fine structure of their epithelia and their luminal contents, characterized by some preliminary histochemistry. A structurally uniform merocrine secretory cell is found throughout the length of the gland. However, the differences that occur do so in the apical surface structure, especially the microvilli and the occasional bleb indicating apocrine activity. The other major element is an apocrine secretory cell with highly modified mitochondria and apical region. The latter consists of compartments which are filled with glycogen and organelles and which protrude into the lumen. The merocrine secretions include a variety of globular structures of varying sizes and densities and two filamentous elements in addition to the matrix. The U-shaped duplex is very short and joined to the accessory glands, vasa deferentia, and simplex. Its epithelium consists of a single cell type; however, there are obvious signs of asynchronous secretory activity in adjacent areas within the duplex. There are also some suggestions of apocrine activity although the epithelium is largely merocrine. The lumen contains, in addition to its own secretions, secretions of the vasa deferentia, apyrene sperm, and eupyrene sperm bundles. The latter are confined to the areas around the openings of the vasa deferentia.