NEUROENDOCRINE CONTROL OF REPRODUCTION IN THE FEMALE FRESHWATER CRAB, BARYTELPHUSA GUERINI (H. MILNE EDWARDS) (DECAPODA : POTAMIDEA)

The neuroendocrine control of female reproductive system was studied in the crab, Barytelphysa guerini. Bilateral eyestalk extirpation in the adult animals in the post reproductive season led to an increase in the size of the reproductive system and ovarian Weight followed by increase in the diameter of oocytes and acceleration of Vitellogenesis. Injection of eyestalk extracts into ablated animals prevents this accelerated growth almost completely, but sinus gland injections resulted only in partial inhibition. Brain and thoracic ganglionic mass extracts did not prevent this accelerated growth. Injection of eyestalk and sinus gland extracts into normal animals resulted in slight inhibition of the reproductive growth, while the central nervous extracts injections caused a slight but not much significant acceleration of the same. Central nervous extracts from 20 days old eyestalk-ablated animals injected into normal animals caused slightly significant increase in the reproductive growth. The female reproductive system was suggested to be under the dual control of the neuroendocrine principles, a gonad inhibiting factor from the eyestalks and gonad stimulating factor from the central nervous structures. The reproductive activity was suggested to be dependent upon the variations in the relative concentrations of these two antagonistic hormones during the different phases of the reproductive cycle.