Hormonal induction of the ovulation and spermiation of the gudgeon Gobio gobio L.
Kestemont, P. (1989). Hormonal induction of the ovulation and spermiation of the gudgeon Gobio gobio L., in: De Pauw, N. et al. (Ed.) Aquaculture: a biotechnology in progress: volume 1. pp. 527-536
In: De Pauw, N. et al. (1989). Aquaculture: a biotechnology in progress: volume 1. European Aquaculture Society: Bredene. ISBN 90-71625-03-6. 1-592 pp., meer
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Documenttype: Congresbijdrage
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| Abstract |
The effectiveness of different hormonal treatments was studied to induce gametes emission of a wild stock of a European baitfish, the gudgeon Gobio gobio L. The fishes were sampled by electro-fishing from the natural environment or from ponds during the spawning season (May and June). Ovulation was easily induced by injection of a carp pituitary extract (CPE) or by injection of a hypothalamic factor, the luteinizing hormone-releasing hormone superactive analog (D-Trp6, des Gly10LHRH) in combination with pimozide (PIM), a dopamine antagonist. The response of CPE injection was dose-dependent, with satisfactory results when using a dosage of 10.0ug.g-1 or more (60% of ovulation). Most responses occurréd 240 to 360 degree-h after injection. The administration of PIM (10.0ug.g-1+LHRH-A (0.1 or 02ug-1) in two successive or in one combined injection was also highly effective in inducing ovulation in gudgeon. Nevertheless, large variations in latency time (240 to 2640 degree-h) occurred. In both experiments, the hatching rate was very variable. The short duration of fecundability of ova (only some hours) explains the failure of fertilization when using PIM+LHRH-A. The variation in hatching rate after CPE injection probably results in stripping of unripe-ova. On the other hand, injection of CPE (10.0ug-1) is likely to stimulate spermiation in the males. The volume of sperm collected in the treated males was four times larger than in the controls. In contrast lower dosage of CPE (1.0 and 5.0ug.g-1) and PIM+LHRH were ineffective to increase spermiation. |
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