The Effects of Pinealectomy on Pituitary Prolactin Levels in Carassius Auratus Exposed to Various Photoperiod-Temperature Regimes

Pinealectomy has an influence on pituitary prolactin levels in goldfish maintained under certain photoperiod-temperature regimes. The effects of pinealectomy on pituitary prolactin content depend on photoperiod and time of sampling. Thus, differences between pinealectomized and sham operated animals may be due to a shift of a daily variation in pituitary prolactin levels. The pineal in fishes may thus be involved in photoperiod influences on daily prolactin rhythms.