纹缟虾虎鱼人工繁殖技术与早期仔鱼生存活力

研究了纹缟虾虎鱼人工繁殖技术和温度、光照、pH等环境因子对其早期仔鱼生存活力的影响。结果表明,采用促黄体素释放激素类似物LHRH-A2、马来酸地欧酮DOM和绒毛膜促性腺激素HCG对纹缟虾虎鱼进行催熟催产效果较好。纹缟虾虎鱼受精卵呈梨形或者梭形,受精率为(78.08±11.39)%,孵化率为(52.82±9.26)%,水温19.0±1.0℃时孵化出膜需208.7 h。胚胎发育分为25个时期,其中心跳期持续时间较长。初孵仔鱼全长2.534±0.078 mm,5日龄时基本完成早期仔鱼发育。17.0~25.0℃时纹缟虾虎鱼仔鱼生存活力指数SAI值随着温度升高而逐渐降低,17.0~21.0℃时SAI值为39.35~42.95,仔鱼活力较强;23.0~25.0℃时SAI值为26.85~34.20,仔鱼活力较弱。光照组与自然光照组仔鱼的SAI值较高,分别为56.47与55.20;黑暗组的SAI值为27.73。高pH组(pH7.5~9.5)仔鱼的SAI值高于低pH组(pH4.5~6.5),高pH组仔鱼的活力更强。综合各项指标表明,长江口纹缟虾虎鱼早期仔鱼发育的适宜生态条件为:温度17.0~21.0℃,每昼夜光照12 h以上,pH 7.5~9.5。

On the artificial propagation technique and survival activity of early larva of Tridentiger trigonocephalus

The artificial propagation technique of Tridentiger trigonocephalus and the surivival activity of the early larva effected by temperature,photoperiod and pH have been investigated.The results showed that the effect of mixed hormones to be used as LHRH-A_2+DOM+HCG for induced maturation and spawning were the better.The form of oosperm of the fish manifested pear-or shuttle-sharped.The fecundity rate and hatching rate respectively was(78.08±11.39)%and(52.82±9.26)%.The hatching period required 208.7 hours under water temperature(19.0±1.0)℃.Embryonic development could be divided into 25 stages,among which heart beating stage lasted much longer.The total length of the initial larva was(2.534±0.078)mm.The development of early larva almost accomplished in five days.Under 17.0 to 25.0℃ the survival activity index(SAI)would decrease as water temperature rises.With SAI 39.39-42.95 and water temperature under 017.0-21.0℃,the larva vigor was stronger and would be weakened with SAI down to 26.85-34.20 and water temperature under 23.0-25.0℃.The.survival activity index was higher both in the continuous illumination and natural illumination groups,the values were 56.47 and 55.20 respectively.SAI and vigor of Tridentiger trigonocephalus early larva in the high pH value groups were higher than those in the lower pH value groups.By synthesizing each index it came to the conclusion that the optimal ecological factors for the early larva development of Tridentiger trigonocephalus were 17.0-21.0℃ of water temperature,over 12 hours round-the-clock photopefiod and 7.5 to 9.5 of pH values.