The current study explicated the effects of serotonin (5-hydroxytryptamine, 5-HT) and dopamine (DA) on ovarian development in the edible freshwater crab Travancoriana schirnerae, distributed in the wetlands of Wayanad. Adult intermoult female crabs in various oogenic stages were administered with 5-HT and DA, weekly once for four weeks and the ovaries processed for histological and biochemical analyses. The results indicated that 5-HT induced ovarian maturation by a significant rise in ovarian index, mean oocyte diameter, oocyte proportion values, gonial proliferation, folliculogenesis and degree of yolk deposition while DA showed a significant decline in the aforesaid parameters thus delaying ovarian growth when compared to the untreated controls. Further biochemical analyses confirmed the 5-HT triggered ovarian growth as evinced from the significant rise in total protein, oligo and polysaccharide fractions, free amino acids, lipid and cholesterol contents compared to the significantly low values of DA-treated group and control crabs. The present study clearly demonstrated the antagonistic effects of 5-HT and DA on ovarian maturation in T. schirnerae. In conclusion, the stimulatory neurotransmitter, 5-HT provides a non-surgical practical solution for inducing ovarian growth and maturation in species of aquaculture importance.

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