Effect of ecdysteroids on oogenesis in the freshwater crab Travancoriana schirnerae Bott, 1969 (Crustacea: Gecarcinucidae)

Abstract

This study evaluated the reproductive performance of female Travancoriana schirnerae Bott, 1969 (Crustacea: Gecarcinucidae) administered with 20-OH ecdysone during different phases of the oogenic cycle. The effect of administration was evaluated by comparing the mean gonadosomatic index, oocyte diameter, oocyte proportion values and histological features of the control and concurrent control ovaries with those of the experimentals. The results clearly indicated that 20-OH ecdysone can stimulate ovarian growth and maturation in all phases of the oogenic cycle, though it caused statistically significant effects only during the early and middle vitellogenic phases, evidenced from the accelerated gonadosomatic index, oocyte diameter and oocyte proportion values, occurrence of vitellogenic oocytes in avitellogenic and previtellogenic ovaries, increased degree of yolk deposition and proliferation of gonia in the experimental ovaries compared to the controls. The outcome of this study is quite promising in the aquaculture practice of this locally abundant edible freshwater crab which forms a cheap protein substitute for the malnourished tribes/poor people of Wayanad.