摘要
为了研究盐度对褐点石斑鱼(Epinephelus fuscoguttatus)♀×清水石斑鱼(Epinephelus polyphekadion)♂杂交后代(简称杂交石斑鱼)受精卵孵化、卵黄囊仔鱼形态及活力的影响,将杂交石斑鱼受精卵置于不同盐度水体中,观察盐度胁迫下卵径、油球径、孵化率及畸形率,以及孵化后卵黄囊仔鱼形态变化和活力状况。结果表明,在本研究条件下,受精卵卵径随盐度降低而增大,油球径不随盐度变化而变化。在盐度18~36范围内均能孵化仔鱼,但因盐度不同孵化率和初孵仔鱼畸形率有显著差异(P<0.05);随盐度升高,孵化率呈先升后降的变化,初孵仔鱼畸形率则相反。盐度24~36组孵化后3 d仔鱼卵黄囊几乎完全消耗,组间无显著差异(P>0.05)。在盐度24~36范围内,随着盐度的增加,仔鱼的不投饵存活系数(SAI值)呈先升后降的变化曲线;盐度30~33范围内,初孵仔鱼SAI值大于5;5日龄仔鱼全部死亡,半数死亡时间出现在孵化后3.5 d。综上分析表明,该杂交石斑鱼受精卵孵化及仔鱼培育的适宜盐度范围为24~36,最适盐度范围为30~33。
Hybridization is the most effective thus widely linity is one of the most crucial environmental variables used technique in the artificial breeding of grouper. Sa- affecting embryonic development in marine fishes. To study the effect of salinity on fertilized eggs of the hybrid grouper （Epinephelus fuscoguttatus ♀×E, poly- phekadion♂） in terms of egg diameter, hatching rate, morphology and survival of the yolk-sac larvae, fertilized eggs were reared in seawater with different salinities, and the effects on total egg diameter, oil globule diameter, hatching rate, abnormality rate, as well as the morphology and survival of the yolk-sac larvae, were observed. The diameter of the fertilized eggs increased with decreases in salinity, whereas the diameter of the oil globule appeared unaffected by the choice of salinity in the test range. Larvae hatched out in the salinity range 18 to 36, but the rates of hatching and abnormalities were significantly affected by salinity level （P〈0.05）. With increases in salinity, the hatching rate first increased at a salinity up to 75.5%, and then decreased at salinity of 30, whereas the rate of abnormalities followed an opposite pattern. The yolk sac was almost completely absorbed within 3 days of hatching at a salinity between 24 and 36, and there was no significant difference between the groups. Within the same salinity range, the survival activity index （SAI） of newly hatched larvae first increased and then decreased with increases in salinity. The newly hatched larvae had an SAI greater than 5; by 5 days after hatching they were starved to death, with half the deaths at 3.5 days after hatching. The fertilized eggs of this hybrid grouper can be hatched out in a salinity range of 24-36, with the optimal salinity at 30-33.
出处
《中国水产科学》
CAS
CSCD
北大核心
2017年第3期507-515,共9页
Journal of Fishery Sciences of China
基金
广东省科技厅项目(2016B020201009)
关键词
褐点石斑鱼
清水石斑鱼
杂交后代
孵化率
卵黄囊仔鱼
盐度
Epinephelusfuscoguttatus
Epinephelus polyphekadion
hybrid
hatching rate
yolk sac larvae
salinity
