Seasonal changes in the structure and secretory activity of the androgenic gland of Travancoriana schirnerae

Abstract

This study investigated the seasonal variation in the structure and secretory activity of the androgenic gland (AG) in the freshwater crab: Travancoriana schirnerae. The androgenic gland is an elongate structure, attached to one side on the wall of the ejaculatory duct. Histological studies showed the presence of three cell types, which differ in size, shape of nuclei, and presence or absence of secretory vesicles. Type I cells are small with large nuclei whereas type II cells are large with small nuclei. Type III cells are intermediate in size and exhibited streak-like nuclei and transparent cytoplasm. Seasonal changes were discerned in the morphology, histology and secretory activity of the gland. March-June appeared to be the active season with type II cells containing secretory vesicles. The mode of release of secretion found to be holocrine. The secretory activity almost completed by July-August (the mating season) with vacuolization of type II cells. The gland remained inactive from September-December with abundance of vacuoles, scattered pycnotic nuclei, indistinct cell membranes and total cellular degeneration. January-February was the revival period with type I cell proliferation. The present study revealed that the secretory activity of the gland is in tune with the male reproductive cycle.

Impact of eyestalk ablation on androgenic gland activity in the freshwater crab Travancoriana schirnerae Bott, 1969 (Decapoda: Gecarcinucidae)

“…In the current investigation, bilateral eyestalk ablation induced hypertrophy and hyperplasia of the AG during the active phase as evidenced by increase in width of the gland, thickness of the connective tissue layer, increase in cell and nuclear diameter with predominance of type I cells. Comparable results were obtained by Demeusy (1960) in C. maenas where removal of eyestalks led to hypertrophy of the AG, signified by ultrastructural features related to hyperactivity. Removal of eyestalks caused hypertrophy and hyperplasia of the gland in the crabs Scylla serrata, R. harrisii, C. sapidus and the shrimp Lysmata seticaudata (Rangnekar et al, 1971;Payen et al, 1971;Touir, 1973).…”

“…Several authors suggested that the AG is under the control of an inhibitory neuropeptide -GIH, secreted from the XO-SG complex of the eyestalks. Demeusy (1953) and Demeusy and Veillet (1958) have observed that secretory activity of the AG is directly regulated by the influence of GIH in C. maenas. Similar observations were recorded by Hoffman (1968) in P. platyceros.…”

“…Literature is plenty regarding the effect of eyestalk ablation on the activity of AG of marine decapods. Demeusy (1960) investigated the role of eyestalks in the differentiation of genital organs in the shore crab Carcinus maenas. The impact of eyestalk ablation on AG activity in the protandric shrimp Pandalus platyceros was reported by Hoffman (1968) and Foulks and Hoffman (1974).…”

Morphology and development of the male reproductive tract in Callinectes danae (Crustacea: Brachyura)

“…Santos et al., ; Goldstein & Dupré, ; Shinozaki‐Mendes et al., ;. Zara et al., ; Devi & Smija, ; Wang et al., ).…”

“…Santos et al, 2009;Goldstein & Dupré, 2010;Shinozaki-Mendes et al, 2012;. Zara et al, 2012;Devi & Smija, 2014;Wang et al, 2015). The morphology of the testes, according to Nagao and Munehara (2003), can be classified as tubular or lobular.…”