Systematics and Biology of the Two Species of Embiotocid Fishes Referred to the Genus Ditrema in Japan
Systematics and Biology of the Two Species of Embiotocid Fishes Referred to the Genus Ditrema in Japan
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日本 Ditrema 属两种杀虫剂鱼类的系统学和生物学
DOI：
10.11369/jji1950.15.105
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发表时间：
1969
期刊：
影响因子：
--
通讯作者：
Y. Abe
中科院分区：
文献类型：
--
作者：
Y. Abe
Ditrema 属的物种在国内外的形式和命名上受到了混乱的对待。最近Yamane(1964)认识到D. temmincki Bleeker和D. viridis Oshima，并进一步根据颜色的差异将前者分为两种类型。本研究以在神奈川县三浦半岛柱水采集的Ditrema标本为基础，从1963年开始一直持续至今，旨在明确其分类地位和生活史特征，并识别出D. temmincki和D. viridis两个种。然而，前者被发现并没有被分为不同的种族、形态或 D. temmincki 物种内的任何其他系统类群。在这两个物种的生活史中发现的最显着的差异是胚胎数量及其出生时的大小。雌性 D. temmincki 平均携带胚胎数为 13.02 个，D. viridis 为 29.65 个，两个物种的雌性在每个年龄段的差异几乎是两倍。出生时胚胎的平均大小为总长 57.4 毫米（D. temmincki）和 49.6 毫米（D. viridis），无论母鱼的大小或年龄，尺寸差距至少为 7-8 毫米。出生时的这种大小差异也可以通过产前生长期间鳞片上形成的脊的数量来证明。通过全国人口普查调查，这两个物种的分布在从北海道南部到九州的整个日本几乎是重叠的。在走水，这两个物种的首选栖息地有所不同。 D. viridis 生活在以大叶藻植被为特征的海湾或入口处的海岸水域，而 D. tern mincki 的常见栖息地则发现于外海的岩石区域。国内的人口普查结果也充分证实了物种栖息地的类似差异。
The species referred to the genus Ditrema has received a confusing treatment on their forms and nomenclature here and abroad. Recently Yamane (1964) recognized D. temmincki Bleeker and D. viridis Oshima, and further, divided the former into two forms by the differences of coloration. The present study, based on the specimens of Ditrema collected at Hashirimizu, Miura Peninsula, Kanagawa Pref., has been started in 1963 and continued to the present in a hope to clarify the status of its taxonomy and features of life history, and recognized two species, D. temmincki and D. viridis. However, the former was found not to be divided into different races, forms, or any other systematic groups within the species D. temmincki. The most significant differences found on the life history between the two species were those of number of embryos and its size at birth. The average number of embryos carried by a female was 13.02 for D. temmincki and 29.65 for D. viridis, the differences being nearly twice in every ages of females between the two species. The averaged size of embryos at birth was 57.4 mm long in total length for D. temmincki and 49.6 mm long for D. viridis, and the size gap, regardless size or age of mother fishes considered to be 7-8 mm at least. Such size differences at birth was also evidenced by the number of ridges formed on the scales during prenatal growth. The distribution of both species, investigated by means of nation wide census, is almost overlapped throughout Japan from southern Hokkaido to Kyushu. The preferred habitat taken by the two species was found to be different between them at Hashirimizu; D. viridis lives in shore waters characterized by Zostera vegetation in the bay or inlet, while, usual habitat of D. tern mincki was found in rocky region of outer sea. Similar difference of habitat by species was also well confirmed by the result of the census in the country.