Distribution, life history, and production of three species of Neomysis in Akkeshi-ko estuary, northern Japan
Distribution, life history, and production of three species of Neomysis in Akkeshi-ko estuary, northern Japan
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日本北部厚岸港口三种新虾的分布、生活史和产量
DOI：
10.1007/s00227-006-0403-4
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发表时间：
2007
期刊：
影响因子：
2.4
通讯作者：
T. Toda
中科院分区：
文献类型：
--
作者：
Katsumasa Yamada;Kazutaka Takahashi;C. Vallet;S. Taguchi;T. Toda
对日本北部厚岸港口常年出现的西北亚北极太平洋沿岸海域三种新糠虾(Mysidacea)的空间和季节分布格局、生活史和产量进行了调查。最丰富的物种Neomysis awatschensis（年平均密度：179.8 inds. m−2，生物量：108.8 mg DW m−2）出现在河口内部，包括低盐度区域，对海草床没有明显的偏好。第二丰富的奇异新螨（平均密度：95.8 inds. m−2，生物量：90.1 mg DW m−2）全年出现在相对咸水的海草地点。夏季河口新糠虾的出现仅限于海草床，当时其种群主要由幼体组成，表明该物种是河口和海洋环境之间的季节性迁徙。两者N.阿瓦茨琴西斯和 N. mirabilis种群由两代类型组成，较大型的越冬代和较小型的春/夏季代；然而，每个物种都有不同的繁殖策略。 awatschensis 的特点是生长速度快，且体型比 N 更小。紫茉莉在温暖季节具有相对较高的繁殖力，表明该物种是一种 R 战略家，可以机会性地利用各种栖息地。相比之下，海草床驻留N。 mirabilis是一种K-策略家，其成熟时体型较大，产生的后代数量较少但体型较大。年产量N. awatschensis（0.57–0.70 g DW m−2，整个河口的平均值）和 N。 mirabilis（0.58–0.68 g DW m−2，海草床的平均值）在各自的栖息地具有可比性。因此，得出的结论是物种特异性的生活史和分布模式允许Neomysisspp。建议在河口共存，海草床的高承载能力有助于维持其高生物量水平。
Spatial and seasonal distribution pattern, life history and production of three species ofNeomysis(Mysidacea) which commonly occur in northwestern subarctic Pacific coastal waters, were investigated throughout the year in the Akkeshi-ko estuary, northern Japan. The most abundant speciesNeomysis awatschensis(annual mean density: 179.8 inds. m−2, biomass: 108.8 mg DW m−2) occurred at the inner part of the estuary including low salinity areas with no clear preference for the seagrass bed. The second most abundantNeomysis mirabilis(mean density: 95.8 inds. m−2, biomass: 90.1 mg DW m−2) occurred at relatively saline seagrass site throughout the year. Occurrence ofNeomysis czerniawskiiin the estuary was limited to the seagrass bed during summer when their population mainly consisted of juveniles, suggesting that this species is a seasonal migrant between the estuary and the marine environment. BothN. awatschensisandN. mirabilispopulations were composed of two generation types, a larger sized overwintering and smaller sized spring/summer generations; however, each species had a different reproductive strategy.N. awatschensiswas characterized by fast growth to maturity at a smaller size thanN. mirabiliswith a relatively high fecundity during warm season, suggesting that this species is an r-strategist which can utilize opportunistically a wide variety of habitats. In contrast, the seagrass bed residentN. mirabiliswas a K-strategist which matures at a larger size producing fewer but larger offspring. The annual production ofN. awatschensis(0.57–0.70 g DW m−2, mean of the whole estuary) andN. mirabilis(0.58–0.68 g DW m−2, mean of the seagrass bed) at their respective habitats was comparable. Consequently, species-specific life history and distribution pattern are concluded to allowNeomysisspp. to coexist in the estuary and the high carrying capacity of seagrass bed is suggested to contribute to maintain their high biomass level.