Sumida Masayuki, Kotaki Manabu, Islam Mohammed Mafizul, Djong Tjong Hon, Igawa Takeshi, Kondo Yasuyuki, Matsui Masafumi, Anslem De Silva, Khonsue Wichase, Nishioka Midori
Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, Higashihiroshima, Japan.
Zoolog Sci. 2007 Jun;24(6):547-62. doi: 10.2108/zsj.24.547.
The rice frog (Fejervarya limnocharis) species complex is widely distributed, from India to Japan, and most prevalently in Southeast Asia. Conspicuous morphological variation has been reported for this species complex throughout its distribution range. In the present study, we used mtDNA gene sequence and allozyme analyses to infer evolutionary affinities within this species complex using eight populations (Sri Lanka; Bangkok and Ranong in Thailand; Taiwan; and Hiroshima, Okinawa, Ishigaki and Iriomote in Japan). We also conducted crossing experiments among four populations from Japan, Thailand, and Sri Lanka in order to find out more about the reproductive isolating mechanisms that might exist among the East, Southeast, and South Asian populations of this species complex. The crossing experiments revealed that the Sri Lanka population is reproductively isolated from the Hiroshima, Bangkok, and Ranong populations by complete hybrid inviability, and that the Bangkok population may be reproductively isolated from the Hiroshima population by partial hybrid inviability. Thus, it is not unreasonable to regard the Sri Lanka population as a species separated from F. limnocharis. The mtDNA and allozyme data showed that the Ranong population is most closely related to the Bangkok population in nuclear genome, but more similar to the Okinawa and Taiwan populations in mtDNA genome. The present, preliminary survey may raise questions about the species status of these particular populations and also about the nature of the biological species concept.
泽蛙（Fejervarya limnocharis）物种复合体分布广泛，从印度到日本，在东南亚最为常见。在其整个分布范围内，该物种复合体都有明显的形态变异报道。在本研究中，我们使用线粒体DNA基因序列和等位酶分析，通过八个种群（斯里兰卡；泰国的曼谷和拉廊；台湾；以及日本的广岛、冲绳、石垣和西表岛）来推断该物种复合体内的进化亲缘关系。我们还在来自日本、泰国和斯里兰卡的四个种群之间进行了杂交实验，以便更深入了解该物种复合体在东亚、东南亚和南亚种群之间可能存在的生殖隔离机制。杂交实验表明，斯里兰卡种群与广岛、曼谷和拉廊种群通过完全杂交不活实现生殖隔离，曼谷种群与广岛种群可能通过部分杂交不活实现生殖隔离。因此，将斯里兰卡种群视为与泽蛙分离的一个物种并非不合理。线粒体DNA和等位酶数据表明，拉廊种群在核基因组上与曼谷种群关系最为密切，但在线粒体DNA基因组上与冲绳和台湾种群更为相似。目前的初步调查可能会引发关于这些特定种群的物种地位以及生物物种概念本质的问题。
