Genetic and morphological characteristics and distribution of the Ryukyuan subspecies of ayu Plecoglossus altivelis.

本文研究了青玉舌鱼（ayu plecogssus altivelis）柳园亚种的遗传、形态特征和分布。在琉球亚种和日本亚种之间发现了一个新的等位基因替换。它们之间的平均遗传同一性为0.78，这表明两个亚种在其基因组中平均只有78%的结构基因是相同的。位于托卡拉海峡北部的雅库岛的Ayu表现出日本亚种的遗传和形态特征。这一事实支持了这两个亚种被托卡拉海峡分开并独立进化的假设。琉球亚种仅在奄美大岛发现。这个亚种在冲绳岛的种群可能已经灭绝。奄美大岛的残余种群应该得到保护。

Genetic and morphological characteristics and distribution of the Ryukyuan subspecies of ayu Plecoglossus altivelis were examined.A new allele substituion was discovered between the Ryukyuan and Japanese subspecies. Average genetic identity between them was 0.78, suggesting that the two subspecies share in common only 78% of total structural genes in their genome on the average.Ayu in Yaku Island, where is in the north of the Tokara Channel, showed genetic and morphological characteristics of Japanese subspecies. This fact supports the hypothesis that the both subspecies were separated by the Tokara Channel and have evolved independently.The Ryukyuan subspecies was found only in Amami-oshima Island. Populations of this subspecies in Okinawa Island probably be extinct. Remnant populations in Amami-oshima Island should be protected.