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淞江鲈(Trachidermus fasciatus Heckel 1840)是一种降海洄游性鱼类,如今在上海内河水系已难见踪迹,为查明长江口水域淞江鲈野生种群是否存在,开展了此项研究。2011年5月,采用拖网方式采得淞江鲈鱼苗51尾;采用淞江鲈工厂化养殖管桶系统模式进行驯养、繁殖和成鱼养殖,至5月底存活40尾,成活率为78.4%,平均全长由(2.9±0.3)cm增长至(3.5±0.3)cm,增长率为20.7%;至10月中旬养成29尾,成活率为72.5%,平均全长为(9.1±1.2)cm,增长率为160.0%。这些成鱼有11对培育成熟用于繁殖,成熟率为75.9%。自行有效产卵6窝,产卵率为54.5%,总产卵量为26 616粒,平均窝卵数为(4 436±647)粒;孵出水花鱼苗24 100尾,孵化率达90.5%。该研究结果表明,目前在东海长江口杭州湾水域,仍有淞江鲈野生种群存在,本研究繁殖的后代原种可作为该种群研究和放流之用。
The Songjianmouth (Trachidermus fasciatus Heckel 1840) is a migratory fish that has migrated downstream and is now inaccessible to inland river systems in Shanghai. This study was conducted to determine whether there is a wild population of the song perch in the Changjiang Estuary. In May 2011, 51 tracts of Songjiang sea bass were obtained by trawling method. Domesticated, breeding and adult fish culture were carried out by using the system of industrialized culture drums of Songjiang perch. By the end of May, 40 survived, with a survival rate of 78.4% The average length increased from (2.9 ± 0.3) cm to (3.5 ± 0.3) cm with a growth rate of 20.7%. By the middle of October, the average length was 29, with a mean survival rate of 72.5% and an average length of (9.1 ± 1.2) cm With a growth rate of 160.0%. These adults have 11 pairs of mature breeding for breeding, maturity rate was 75.9%. The number of eggs laid on their own was 6 litters, the fecundity rate was 54.5%, the total number of fecundity was 26 616, and the average number of eggs per litter was (4 436 ± 647) grains. 24 100 were hatched and the hatching rate was 90.5%. The results of this study show that there is still the existence of the wild population of the Songjak perch in the waters of the Hangzhou Bay at the mouth of the East China Sea in the Yangtze River estuary. The offspring of the breeding progeny in this study can be used for the study and release of this population.