Genetical and behavioral studies on geographic variation and speciation in the genus Eumeces in Japan

伊豆群岛和日本主岛分别分布有冈田石龙子和宽叶石龙子两种。我们的初步遗传研究表明，伊豆白纹伊豆的种群可能属于岛型，即冈田章鱼。我们调查了该物种在Hoshu的分布情况，发现了两个物种的分布边界。西部边界位于富士河，东部边界位于小田原和镰仓之间。等位酶分析表明，小田原种群属于伊豆半岛和伊豆群岛种群的聚类群，其中一个杂交种是从小田原种群获得的。这两个种群之间的物种识别行为实验于1998-1999年进行。在第一年，实验失败了，因为繁殖在非常温暖的春天开始得太早了。1999年，我们再次进行了这些实验。结果表明，京都产宽尾松毛虫雄虫对同种雄虫有明显的区别。京都的大多数男性袭击了大分、九州的男性以及对照组。它们没有攻击来自伊豆群岛三库拉-吉马和小津岛的雄性冈田鱼。在某些情况下，它们试图与它们交配。小田原雄鼠并没有被攻击为冈田美洲虎的雄鼠。这些结果强烈地表明，两个物种相互识别，它们是在Mayr意义上的生物物种关系中。

Two species, Eumeces okadae and E. latiscutatus have been considered to be distributed in Izu Islands and Japan main islands, respectively. Our Preliminary genetic study suggested that the population of Izu Penisula may belong to the island form, E. okadae. We surveyed the distribution of this species in Hoshu and discovered the distribution boundaries of the two species. The western boundary is situated in Fuji-river, and the eastern boundary is between Odawara and Kamakura. Allozyme analyses showed the Odawara population is included in a cluster of the populaiotns of Izu Peninsula and Izu islands and one hybrid was obtaine from the Odawara population.Behavioral experiments on species recognition between these two species were conducted in 1998-1999. In the first year the experiments were failed because the breeding started too early in tremendously warm spring. In 1999 we conducted again these experiments. Results indicated that males of E. latiscutatus from Kyoto discriminated conspecifice males. Most males of Kyoto attacked males of Oita, Kyushu as well as a control. They did not attack males of E. okadae from Mikura-jima and Kozu-shima, Izu Islands. In some case, they tried to copulate with them. The Odawara males were not attacked as males of E. okadae. These results stongly suggested that two species recognize each other and they are in the relationship in biological species in the sense of Mayr.