Integration of marine fisheries Biology and preservation biology for the Ariake temperate bass and Chinese temperate bass

我们调查了有明海筑后河口的有明温鲈种群的各种生态学特征，以及作为有明温鲈种群亲本种之一的乌瓦吉马附近的中国温鲈的生长、成熟和仔鱼分布。一种以有明特有种中华哲水蚤（Sinocalanussinensis）为主，分布于低盐度区，尤其是1 ~ 3 psu盐度区。另一类为多种类群，如大森细蜱、戴氏剑水蚤、小拟哲水蚤和海洋拟镖水蚤。前一组总是从最大浑浊带发现。中国对虾消化道内容物主要由色素组成，而叶绿素a主要存在于常见桡足类的消化道内容物中。这些事实表明，碎屑食物链存在于河口上游地区。 ...更多信息 新银鱼、刺虎鱼、条纹粗皮鱼仅捕食中华银鱼。利用人工饲养试验测定的营养富集值和半衰期值，对温性鲈鱼幼鱼和肌肉的δ ^<13>C分析表明，温性鲈鱼幼鱼在4月向淡水区迁移，5 ~ 7月向中盐区迁移，在11月和12月，从养殖围栏中逃逸或被丢弃的中国鲈鱼生长速度比日本鲈鱼快，性腺体细胞指数显著增加。我们认为它们可以在日本沿海沃茨成功繁殖，但我们无法收集到卵、幼虫和幼体。DNA分析表明，中国大陆的南方和北方分布有两个地方种群。在有明海域没有发现中国鲈鱼，而且所有有明鲈鱼都同时具有日本和中国鲈鱼特有的基因，这表明筑后河口上游存在一个以高浊度咸水特有桡足类特有幼鱼紧密连锁为特征的独特生态系统。在中国或朝鲜河口的模式场中进行同样类型的实地研究似乎是必要的。少

We have investigated various ecological aspects of the Ariake temperate bass population in the Chikugo estuary, Ariake Sea, and also growth, maturation and larval fish distribution of the Chinese temperate bass around Uwajima area, which was revealed as one of parental species for the Ariake population.Copepod distribution was separated by 2 groups : one is mainly composed of Ariake endemic species Sinocalanus sinensis which occupied low salinity area, particularly in 1 to 3 psu salinity. The other one is a group of multi-species like Acartia omorii, Oithona davisae, Paracalanus parvus and Pseudodiaptomus marinus. The former group was always found from the turbidity maximum. Major parts of gut contents of S.sinensis were composed of phaeo-pigment, while chlorophyll-a was dominantly detected from the gut contents of common coastal copepod species. These facts suggest that detritus food chain exists in the upper estuarine area.Juvenile stages of the Ariake endemic fishes as Coilia nasus, … More Neosalanx reganius, Acanthogobius hasta, Trachidermis fasciatus preyed exclusively S.sinensis. In contrast, common coastal fishes like amchovy and rock fish which are distributed in the estuary higher than 15 psu in salinity preyed a large variety of copepod species.Using the trophic enrichment value and half-life value determined under rearing experiments, δ ^<13>C of gut contents and muscle showed temperate bass juveniles immigrated into freshwater area in April, shifted to intermediate saline area in May to July, and finally emigrated to sea area in August.Chinese temperate bass, which escaped from aquaculture-pen or were discarded, could grow faster than the Japanese bass and the gonad somatic index markedly increased in November and December. We supposed they could successfully reproduce in Japanese coastal waters, but we could not collect eggs, larvae and juveniles. DNA analyses demonstrated there are two local populations in southern and northern areas of Chinese, continent. We could not find Chinese temperate bass in Ariake Sea, and all Ariake temperate bass have both genes special for Japanese and Chinese temperate bass.These results suggest that there is a unique ecosystem characterized by strong linkage of highly turbid brackish water- endemic copepod-endemic fish juveniles in the upper Chikugo estuary. It appears to be needed to conduct a same type of field research in a model field of Chinese or Korean estuary. Less