虾夷扇贝天然苗种中间育成技术研究

自然海区采集的虾夷扇贝苗种比人工苗种晚2个月,为了实现当年采苗,当年培育成3 cm以上增养殖用苗种,2006—2008年,就虾夷扇贝中间育成技术开展了试验研究。育成密度为90~110个/层,密度对中间育成率影响不显著。密度为70~90个/层,平均壳高达到3.28 cm,群体组成中≥3 cm个体比例为83.33%;密度为120~130个/层,平均壳高3.08 cm,群体组成中≥3 cm个体比例为61%;密度为160~170个/层,平均壳高2.77 cm,群体组成中≥3 cm个体比例仅为22%,密度对苗种生长影响显著。分苗时间早晚对苗种生长有一定影响,分苗时间早,天然苗可充分利用7-8月快速生长期快速生长,提高3 cm以上个体的育成率。中间育成期间的水温对育成率有一定影响,23℃以上水温持续时间较长时,育成率下降。

The Interimediate Breeding of Wild Spats for Japanese Scallop Patinopecten yessoensis

The intermediate culture of wild Japanese scallop Patinopecten yessoensis spats collected two months later than the artificial spat was conducted to produce over 3 cm shell length juveniles for aquaculture from 2006 to 2008. It was found that there was no significant difference in survival at stocking density from 90 to 110 individuals/layer in a net cage. The scallop was 3.28 cm in average shell height at the stocking density of 70～90 ind/layer, in which the individuals with shell height of over 3 cm accounting for 83.33%. When the densities were 120～130 ind/layer, the scallop was 3.08 cm in average shell height, the individuals with shell height of over 3 cm accounting for 61%. The scallop was 2.77 cm in average shell height at stocking density of 160～170 ind/layer, the individuals with shell height of over 3 cm accounting for only 22%. Restocking time affected significantly the growth of the scallop. The wild spat growth was improved in July and August by early restocking and thus large size scallop was obtained. The survival of the wild spats was reduced at water temperature of over 23 ℃ during the intermediate breeding.