HISTO-MORPHOLOGICAL CHANGES IN GONADOTROPHS OF INDIAN MAJOR CARP, LABEO ROHITA (HAMILTON-BUCHANAN, 1822) IN RELATION TO OVARIAN MATURATION.

Pituitary of Labeo rohita is a small pear-shaped, whitish soft body lying on ventral side of the brain immediately behind the optic chiasma in sella turcica on the floor of cranium. Gonadotrophs of the Indian majopr carp were distributed in the proximal pars distalis (PPD) of pituitary gland. Number of cynophils (gonadotrophs) exhibited wide fluctuations with the ovarian maturation. In fact, acidophils (somatotrophs) predominated during non-breeding phases whereas number of cynophils increased and they became the major cell type of PPD as maturity advanced. These cynophils displayed hypertrophy and varying degrees of granulation as well as vacuolization (degranulation) in relation to ovarian maturation. Some cynophils of PPD that did not exhibit marked hypertrophy or degranulation in relation to maturity were identified as thyrotrophs. [ABSTRACT FROM AUTHOR]