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描述紫红笛鲷Lutjanusargentimaculatus繁殖特性及人工诱导产卵的试验结果。紫红笛鲷养殖群体具有不完全的先雄后雌的性转化现象。1、2龄鱼全部为雄鱼,性腺成熟系数(GSI)为2.07%—4.85%;3龄亲鱼80%为雄鱼,20%转化为雌雄同体;4龄亲鱼性别转化基本确定,多数亲鱼为纯粹具有生殖机能的雄鱼,而在雌雄同体的亲鱼性腺中具有明显雌性第一性征的雌鱼仅占30%左右;雌雄同体的亲鱼性腺GSI为4.12%—8.09%,其中的卵巢GSI小于2%,4龄雌鱼怀卵量约70—100万粒;紫红笛鲷卵母细胞属非同步性发育,一个生殖季节能多次产卵。试验结果表明:低剂量的LHRH A2(3μg·kg-1)多次注射能有效地促进性腺发育、逐步成熟,并最终产卵,但对卵径小于300μm的亲鱼卵巢没有明显的诱导效果。在5μgLHRH A2+1000I UHCG·kg-1或5μgLHRH A2+500IUHCG·kg-1两种不同剂量的混合激素作用下,亲鱼的性腺都能迅速发育成熟,并能在小型循环式产卵池中自然产卵和受精。在水温为26.0—29.5℃的产卵池中,激素效应时间为35—43h。LHRH A2和HCG混合激素对卵母细胞直径达到400μm以上的紫红笛鲷亲鱼具有良好的促熟和催产效果,催产率达100%。如何减轻亲鱼之间相互残杀是改善雄鱼生理状况、保证雄鱼质量和提高卵子受精率必需解决的重要问题。
The reproductive characteristics of Lutjanusargentimaculatus and the results of artificial induced spawning were described. The purple red snapper cultured population has incomplete conversion of the ancestors after the female sex. The first and second instar fish were all male, the gonad maturation coefficient (GSI) was 2.07% -4.85%. The third instar brood fish were male and 20% were transformed into hermaphrodite. The gender conversion of the fourth instar broodstock was basically confirmed, most of the broodstock were pure The males with reproductive function, however, accounted for only about 30% of the females with obvious female sexual gonads in hermaphroditic gonads. The gonads of hermaphroditic gonads had a GSI of 4.12% -8.09%, of which the ovary GSI was less than 2% The fourth females have about 70-100,000 eggs. The oocyte of the genus Aquila is a non-synchronous development and spawns repeatedly in one reproductive season. The results showed that low injection of LHRH A2 (3μg · kg -1) can effectively promote gonadal development, gradually mature and finally lay eggs, but no significant induction effect on brood fish ovaries less than 300μm. Under the mixed hormone of 5μgLHRH A2 + 1000I UHCG · kg-1 or 5μgLHRH A2 + 500IUHCG · kg-1, the gonad of the broodstock could rapidly mature and naturally produce in the small circulating oviposit Eggs and fertilization. In the spawning pool with water temperature of 26.0-29.5 ℃, the hormone effect time is 35-43h. LHRH A2 and HCG mixed hormones had good ripening and oxytocic effect on purple snapper broodstock with oocyte diameter over 400μm and the rate of oxytocin was 100%. How to reduce the mutual killing of broodstock is an important issue which must be solved to improve the physiological condition of male, ensure the quality of male fish and enhance the fertilization rate of eggs.