Impact of environmental stresses on breeding biology of Mahseeras reflected in pituitary of Tor putitora (Ham.)

Environmental factors influencing the breeding biology of threatened fish Tor putitora (Ham.) has been investigated as reflected in the interplay hormonal activities in the pituitary gland in relation to the harsh climatic condition in the upland waters. During the annual breeding cycle of this species six types of hormonal cells have been identified, which includes two types of acidophils and four basophils. Based on the histochemistry, intensity and location of these cells four different phases have been assigned to the annual breeding cycle of Mahseer inhabiting the upland waters. It has been inferred that the hormonal interplay in the pituitary gland has a direct bearing on the seasonal maturity of different fish species in relation to the environmental factors. Therefore, if we can manipulate the hormonal activities in the pituitary gland of a particular species the maturity period can be enhanced or delayed as per the requirement of the area.