Seasonal effects of pinealectomy on the ovary of the catfish Heteropneustes fossilis (Bloch) under normal photothermal conditions.
Pinealectomy of Heteropneustes fossilis held under normal photoperiod and ambient temperature produced season-dependent effects on ovarian activity. When the fish were pinealectomized in the preparatory phase (early light-responsive period) and maintained until the early prespawning phase, there was an accelerated growth of the ovary, as adjudged from increased gonado-somatic index (GSI), ovarian histology, elevated ovarian total protein and ascorbic acid levels, and an increased level of serum alkali-labile protein phosphorus (vitellogenin). Pinealectomy was ineffective in the prespawning and spawning (late light-responsive phase) and postspawning (light refractory) phases. The results suggest that the pineal exerts an inhibitory effect on the hypothalamo-hypophysial-ovarian axis and synchronizes temporally ovarian activity in response to increasing photothermal conditions such that spawning takes place at a time most suitable for the survival of the young.
Joy
K P
KP
Department of Zoology, Banaras Hindu University Varanasi, India.
Agha
A K
AK
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D002397:Catfishes; D005260:Female; D006003:Glycogen / Q000378:metabolism; D008027:Light; D009865:Oocytes / Q000378:metabolism; D010053:Ovary / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology*; D010870:Pineal Gland / Q000502:physiology / Q000601:surgery*; D011506:Proteins / Q000378:metabolism; D012621:Seasons; D013696:Temperature; D014819:Vitellogenins / Q000097:blood
D011506:Proteins; D014819:Vitellogenins; D006003:Glycogen; D001205:Ascorbic Acid