Morphology and histology of the ductus receptaculi and accessory glands in the reproductive tract of the female cricket, Teleogryllus commodus

Abstract

The morphology and histology of the ductus receptaculi and accessory glands in females of the black field cricket, Teleogryllus commodus Walker (Orthoptera: Gryllidae) are described. Both are reproductive organs situated in the 7th and 8th abdominal segment that join the posterior part of the genital chamber. The ductus receptaculi is a long (up to 25 mm) homogeneous tube, and the accessory glands (total length: 4 to 12 mm) are a complex system of tubes and end lobes with various numbers of ramifications. Based on their external shapes the accessory glands may be subdivided into three distinct regions, a distal region mainly producing the gland's secretion, a middle conducting region, and a basal region serving for the storage and release of the secretory substances into the genital chamber of the female. In histological respects, both organs have an outer muscle coat followed by a basal lamina, one or two cell layers, the cuticular intima, and the inner lumen. The ductus receptaculi is subdivided into three histologically different regions. The region located adjacent to the receptaculum and the region neighbouring the terminal papilla consist of a single, epithelial cell layer that is not secretory. The epithelium of the middle region contains two cell layers, glandular cells and cuticula-forming cells, which are responsible for the production of the cuticular intima. The secretion of the gland cells is released into an extracellular cavity, through which it reaches the lumen via a complex network of canals running through the intima. The histology of the accessory glands is rather homogeneous among the different regions, as one layer of epithelial cells produces both the secretion and the cuticular intima. Histological variations in the distal, middle, and basal gland sections mainly concern the height of the epithelium, the thickness of the basal lamina and the cuticular intima as well as the variable presence of the outer muscle coat. In contrast to the ductus receptaculi, secretory substances produced by the accessory gland cells accumulate in the lumen by a diffusive permeation of the intima.