An upwelling system for culturing common octopus paralarvae and its combined effect with supplying natural zooplankton on paralarval survival and growth
An upwelling system for culturing common octopus paralarvae and its combined effect with supplying natural zooplankton on paralarval survival and growth
复制标题
培养普通章鱼副幼虫的上升流系统及其与供应天然浮游动物对副幼虫生存和生长的综合影响
DOI：
10.1016/j.aquaculture.2018.05.036
复制
发表时间：
2018
期刊：
影响因子：
4.5
通讯作者：
Hamasaki Katsuyuki
中科院分区：
文献类型：
--
作者：
Dan Shigeki;Iwasaki Hiraku;Takasugi Arata;Yamazaki Hideki;Hamasaki Katsuyuki
尽管人们对章鱼养殖的兴趣越来越大，但章鱼在繁殖期的大量死亡仍然阻碍了生产。在鱼饲养试验期间死亡之前，可以观察到捕获食物的鱼倾向于在通风系统诱导的水流中向下移动，最终将动物沉积在池底。本研究的目的是探讨可能支持幼体游动和漂浮的上升水流对幼体存活和生长的影响。提出了一种新的人工上涌式养殖系统，该系统利用池中心到底部的强烈向下流动。新系统与供应天然浮游动物（主要是十足类甲壳动物）或卤虫相结合的效果进行了评估，使用三个不同的育雏孵化从三个母亲（育雏A，B，和C）。作为浮游动物的食物项目，n-3高度不饱和脂肪酸（n-3 HUFA）强化的轮虫和可消化的微藻Nannochloropsis oculata。幼体干重在各窝间差异显著，表现为A窝> C窝> B窝。与使用标准系统相比，使用上升流饲养系统显著提高了幼鱼存活率，并且幼鱼生长在补充浮游动物的上升流系统中时显著更快。上升流+浮游动物组的副轮虫孵化后18天的存活率仍保持在80%以上。20日龄时，A育雏的成活率可达80.8%，而B和C育雏的成活率则分别下降到8.2%和54.4%，这可能是由于幼体体积小和食物供应不足的综合影响。A、C两个亲贝在25和23日龄时达到底栖阶段，成活率分别为51.0%和45.3%。总体结果表明，不适当的水流环境，结合食物的质量和数量差是主要原因的普通章鱼的人工死亡。为培养轮虫，结合使用的上升流饲养系统和供应十足类甲壳动物Zoeae补充n-3 HUFA强化轮虫和消化N。推荐使用oculata。
Despite a growing interest in common octopus for aquaculture, massive mortalities during the planktonic paralarval stage still hamper production. Prior to die-off during rearing trials for paralarvae, it could be observed that the food-capturing paralarvae tended to be carried downward in a current induced by the aeration system, eventually depositing the animals on the tank bottom. The aim of this study was to investigate the effect of upwelling water-flow, that might support paralarval swimming and floating, on paralarval survival and growth. A new artificial upwelling rearing system using a strong downward flow in the center to the bottom of the tank was developed. The effects of the new system in combination with supplying natural zooplankton (mainly decapod crustacean zoeae) orArtemiawere evaluated using three different broods hatched from three mothers (broods A, B, and C). As food items for zooplankton, n-3 highly unsaturated fatty acid (n-3 HUFA)-fortified rotifers and digestible microalgaeNannochloropsis oculatawere supplemented. The hatchling dry weight was significantly different among broods, showing heavier weight in order of broods A > C > B. Use of the upwelling rearing system significantly improved the rate of paralarval survival as compared with using the standard system, and paralarval growth was significantly faster when reared in the upwelling system with zooplankton supplementation. Paralarvae in the upwelling + zooplankton group kept high survival rates over 80% until 18 days after hatching (DAH). The survival rate of the tank of brood A could achieve 80.8% at 20 DAH, however, those of broods B and C dropped to 8.2% and 54.4% at 20 DAH, respectively, presumably due to combined effect of small hatchling size and insufficient food supply. The octopuses of broods A and C reached benthic stage by 25 and 23 DAH, with survival rates of 51.0% and 45.3%, respectively. The overall results suggest that an inadequate water-flow environment in combination with poor food quality and quantity are major causes of paralarval mortality of the common octopus. For culturing paralarvae, the combined use of an upwelling rearing system and supplying decapod crustacean zoeae supplemented with n-3 HUFA fortified rotifers and digestibleN. oculatawas recommended.