Neuroendocrine regulation of ovarian maturation in the Indian white prawn Penaeus indicus H. Milne Edwards

Abstract

Neuroendocrine Regulation of ovarian maturation in the Indian white prawn Penaeus indicus H. Milne Edwards. Aquaculture, 98: 381-393. The control and regulation of ovarian maturation by neurosecretory elements in the eyestalk, brain and thoracic ganglia of Penaeus indicus have been examined. In the X-organ complex of the eyestalk, secretions from type A and B cells are apparently involved in inhibiting ovarian maturation, while in the brain and thoracic ganglia, secretions from type GN, A and B ce!ls had a stimulatory effect on the ovary. The pyriform C cells were not involved with ovarian maturation. Both unilateral and bilateral eyestalk ablation resulted in precocious maturation of the ovary. The histology of the remaining eyestalk in unilaterally ablated animals revealed that all the NSCs in the X-organs were in a suppressed state and the sinus gland was devoid of granular aggregations. Abnormal behaviour was noticed in bilaterally ablated prawns and strangely few animals moulted with developing ovaries. Due to the synchronous occurrence of moulting and reproductive activities the probability of both gonad and moult inhibiting hormones being the same is discussed. In addition the relationship between gonadal maturation and the moult cycle has also been studied.