以人工合成的17α-羟孕酮(17α-P)、17α,20β-双羟孕酮(17α,20β-P)、前列腺素E2(PGE2)和前列腺素F2α(PGF2α)作为性信息素,吊挂在陶瓷管道内诱发性成熟野生和养殖中华乌塘鳢产卵,以陶瓷管道产卵率、总产卵量和平均受精率为指标,比较了两者的产卵效应,测定了产卵水和生活水(未产卵水)中PGE2和PGF2α的含量以及性腺提取液中17α-P、PGE2和PGF2α的含量。结果表明,性信息素能明显提高诱发中华乌塘鳢的产卵效应。在同等实验条件下,诱发野生鱼的产卵效应优于养殖鱼。野生鱼和养殖鱼产卵水中的PGE2和PGF2α水平分别高于生活水中的,野生鱼和养殖鱼产卵水中的PGE2水平均极显著高于PGF2α(P<0.01)。PGE2在卵巢、精巢和贮精囊提取液中的含量,野生鱼均高于养殖鱼。The authors used synthetic steroids 17α-P and 17α,20β-P,and prostaglandins PGE_2 and PGF_ 2α as sex pheromones to induce spawning for the wild and cultured mature Chinese black sleepers(Bostrichthys sinensis).Effects of these sex pheromones on spawning were compared between the wild fish and cultured ones in nest spawning rate,total number of eggs,and mean fertilization rate.PGE_2 and PGF_ 2α levels of the spawning and holding waters,and 17α-P,PGE_2 and PGF_ 2α levels of the gonadal extracts were determined,separately and respectively. The wild fish were caught in the intertidal zone of Jiulong River estuarine,Fujian,10.5—19.3cm in body length and 20.2—139.0g in body weight,and the cultured ones were collected from farming ponds in Dongshan County,Fujian,11.7—17.4cm in body length and 62.9—151.6g in body weight.Plastic tanks(81cm×58cm×45cm)were used in the experiment.Artificial ceramic nests were placed on the bottoms of the tanks,two nests each tank,and then two pairs of mature fish,induced by hormones,were introduced into every tank.The fish were randomly divided into four hormonal treated groups(i.e.17α-P,17α,20β-P,PGE_2 and PGF_ 2α ).Induction of spawning for both wild and cultured fish were investigated in three equivalent trials respectively,in two tanks for each trial conducted in parallel.Solution of synthetic steroids 17α-P,17α,20β-P,prostaglandins PGE_2 and PGF_ 2α was injected into a plastic tube at a dosage of 100μg,and then the plastic tube was fixed inside the ceramic nest.Each plastic tube containing sex pheromone solution was pluged by a piece of cotton.In this case,sex pheromones seeped slowly through the cotton into the inner water of the nests.During the experiment,water temperature varied from 23.5℃ to 29.5℃.17α-P,PGE_2 and PGF_2 levels in the extracts of ovary,testis and seminal vesicle,as well as in spawning and holding waters were determined by enzyme-linked immunosobent assay(ELISA). The results showed that sex pheromones evidently increased the spawning efficiency of the wild fish.The nest spawning rate,the total number of eggs and the mean fertilization rate in the sex pheromone treated groups were higher than those of the control.The highest nest spawning rate was found in the 17α-P treated group,followed by the 17α,20β-P treated group,PGE_2 treated group and PGF_ 2α treated group in order.The largest egg number was obtained from the 17α-P treated group,followed by PGE_2 treated group,PGF_ 2α treated group and 17α,20β-P treated group,and each of them was larger than that of the control respectively.The mean highest fertilization rate was found in the PGE_2 treated group,followed by 17α-P treated group,17α,20β-P treated group and PGF_ 2α treated group.The highest fertilization rate of each treated group reached above 98%.Sex pheromones were more effective in inducing spawning of the wild fish than the cultured ones under the same conditions.The nest spawning rates of the wild fish were 9 and 4 times higher than those of the cultured ones treated with 17α-P and 17α,20β-P,respectively.The total egg numbers of the wild fish were 52.8 and 54.9 times as many as those of the cultured ones treated with PGE_2 and PGF_ 2α respectively.PGE_2 and PGF_ 2α levels of the spawning water were higher than those of the holding water of the wild fish and the cultured ones.PGE_2 levels were significantly higher than PGF_ 2α in the spawning waters of the wild fish and the cultured ones.Ovarian 17α-P level of the wild fish was higher than that of the cultured fish,but not significantly. PGE_2 levels of ovary,testis and seminal vesicle of the wild fish were higher than those of the cultured ones correspondently.PGF_ 2α levels of ovary and testis of the wild fish were similar to those of the cultured ones.国家自然科学基金资助项目,40476056号、30170739号
