Photoperiodic control on the ovary and pituitary gonadotrophs in Puntius sarana (Hamilton).

Exposure of the fish to a long photoperiod (16L/8D) during the prespawning period accentuates the development of the ovary and increases the secretory activity of the pituitary gonadotrophs (GtH cells). A short photoperiod (8L/16D) or total darkness brings about follicular atresia of the vitellogenic oocytes and inhibits secretory activity of the GtH cells. Both the vitellogenesis and the GtH cell activity are restored in the fish exposed to short photoperiod if it is followed by a long photoperiod. Results indicate that the photoperiod plays a major role in controlling the reproductive activity in the teleost, Puntius sarana.