金乌贼新型产卵附着基的实验研究

2015年6—7月和2016年6—7月在青岛金沙滩水产有限公司室内产卵池中开展了不同材料、不同颜色、不同水深金乌贼(Sepia esculenta)产卵附着基附卵效果对比实验,以及柽柳附卵器对附卵效果的影响实验。实验用产卵附着基为0.33 m×0.33 m×0.33 m的十字形可折叠钢丝框架,上覆黑白2种聚乙烯网衣材料;每个产卵池中金乌贼亲体数量约35只,雌雄比约为1∶1,胴长(139.2±1.1)mm,体重(435.9±8.5)g。同时选用等比例放大的1.0 m×1.0 m×1.0 m钢筋框架与不同颜色网衣制作的十字形可折叠附着基,于2015年6—7月在青岛斋堂岛附近海域(35?36?6?N,119?54?8?E)和杨家洼湾前附近海域(35?36'6?N,119?50'50?E),以及2016年6—7月在青岛薛家岛近海(35?57?24?N,120?16?22?E)和杨家洼湾前附近海域(35?35?45?N,119?50?38?E)开展了海区附卵验证实验。结果表明:室内同一水体环境中柽柳附卵效果最佳,其次是十字形附着基,海参框附卵效果最差;白色十字形附着基的附卵效果显著优于黑色(P0.05);柽柳附卵器对附卵效果有积极影响,加装柽柳附卵器的十字形附着基附卵效果明显提高;产卵池底层摆放的十字形附着基的附卵效果显著优于表层悬挂的十字形附着基(P0.01)。海区附卵验证结果表明:2015年和2016年海区投放的十字形附着基附卵效果良好,最高附卵率分别为82.14%和56.72%;海区投放的黑色和白色十字形附着基的附卵效果差异不显著(P0.05);海底悬挂的十字形附着基的附卵效果显著优于近底层悬挂的十字形附着基(P0.05)。综合分析认为,在金乌贼产卵繁殖季节,选择其重要产卵场和主要增殖放流海区水深15~20 m的缓流区,底层设置十字形可折叠产卵附着基,可有效进行资源增殖与产卵场修复。

The efficacy of new spawning substrates for Sepia esculenta oosperm adhesion

In recent years, Sepia esculenta stock enhancement in Shandong province has been carried out in two ways. One is to release hatchery-reared juvenile S. esculenta. The other is to provide suitable spawning substrates made of salt cedar branches or sweet wormwood branches. The materials for the spawning substrates are cheap, and the substrates are also appropriate for S. esculenta spawning and thus helpful for S. esculenta in situ conser-vation and enhancement. However, the materials can't be reused and are easily damaged on transportation and deployment. Furthermore, successive cuttings of salt cedar and sweet wormwood significantly damage the two terrestrial plant species. Therefore, in order to improve S. esculent stock enhancement and to further expand the stock enhancement scale, identification of environment-friendly spawning substrates has become an important issue. A study on different types of spawning substrates for S. esculenta oosperm adhesion was conducted in an indoor spawning pool. Additionally, the adhesion of S. esculenta oosperms to the spawning substrates was also examined in the field. The results of the indoor experiment showed that the adhesion of the oosperms on salt cedar branches was the best, followed by that on the cruciform spawning substrates, with that on the sea cucumber frame being the worst. The adhesion of oosperms on the white cruciform spawning substrates was significantly better than on the black ones (P<0.05). Attaching salt cedar branches to the cruciform spawning substrates significantly increased oosperm adhesion. In addition, oosperm adhesion on the cruciform spawning substrates, which were placed at the pool bottom, was significantly better than those hung in the upper water (P<0.01). In the field ex-periment, the results showed that oosperm adhesion to the cruciform spawning substrates was good in both 2015 and 2016, with highest oosperm adhesion rates being 82.14% and 56.72%, respectively. Oosperm adhesion was not significantly different between the black and the white cruciform spawning substrates (P>0.05). Oosperm adhesion to cruciform spawning substrates that were hung at the sea bottom was significantly better than on those hung near the sea bottom (P<0.05). The results suggested that, in the spawning season of S. esculenta, resource enhancement and comprehensive protection of the spawning population can be achieved effectively by deploying artificial cru-ciform and collapsible spawning substrates at the sea bottom in its spawning grounds and in the main enhancement and releasing areas of slack water with depths of 15-20 m.