Pituitary gland of the exotic carp, Carassius carassius Linn., with reference to the histocytology of the adenohypophysis in conjunction to male and female rhythms of reproduction.
The pituitaries of the exotic carp (Carassius carassius) are studied at the light microscopic level, for the characterization of the adenohypophysial cell-types with particular emphasis to the gonadotropic potency of the pituitary in relation to the annual reproductive patterns. The gland in the fish is of the cranioleptobasic type. Based on the classical staining methods and localization of the differential cell-types, the adenohypophysis of the fish can be subdivided into the rostral (RPD) and proximal (PPD) pars distalis and the pars intermedia (PI). The pars nervosa (PN) of the fish consists of the neurosecretory (NS) fibres which show varied accumulations of the NS material in concert with the seasonal reproductive cycle. The NS tract is constituted of AF--ve nucleus praeopticus and AF + ve nucleus lateralis tuberis. 2 tinctorially different cell-types, corresponding to corticotrops and lactotrops of other teleosts, are identifiable in the RPD of the present species. In the PPD, 3 cell-types can be distinguished with various granule-staining procedures: they represent somatotrops, thyrotrops, and gonadotrops. Further, 2 gonadotropic cells with apparently different staining properties are discernible. In the PI are dispersed besides a few agranular cells, islets of 2 kinds of cells separable with combined PAS-PbH technique. Seasonal changes in the gonadosomatic index and diameter of the testicular lobules and egg diameter as indices of gonadal maturation are found to be closely interwoven with the morphometric alterations in the basophilic cell area (BCA) chosen as criterion of gonadotropic potency of the PPD. The maximum BCA values are preceded with the time of greatest atresia of the eggs indicating the influence of the pituitary gonadotropins in the follicular resorption in the test fish.
D000064:Acclimatization; D000531:Altitude; D000818:Animals; D002347:Carps / Q000033:anatomy & histology*; D003530:Cyprinidae / Q000033:anatomy & histology*; D005260:Female; D008297:Male; D009866:Oogenesis; D010507:Periodicity; D010903:Pituitary Gland, Anterior / Q000033:anatomy & histology*; D010908:Pituitary Hormones, Anterior / Q000378:metabolism; D012098:Reproduction; D012621:Seasons; D013091:Spermatogenesis
D010908:Pituitary Hormones, Anterior