Tominaga Atsushi, Matsui Masafumi, Nishikawa Kanto
Faculty of Education, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, JAPAN.
Zootaxa. 2019 Jan 29;4550(4):525-544. doi: 10.11646/zootaxa.4550.4.3.
Two new species of lotic-breeding salamanders, Hynobius sematonotos and H. oyamai, are described from Chugoku district and northeastern Kyushu district, respectively, western Japan. They are members of the so-called H. naevius group and are phylogenetically close to H. naevius, H. katoi, and H. hirosei but divergent from them with large genetic distances. These new species have been treated as Chugoku and northeastern Kyushu lineages, respectively, of H. naevius to which they are morphologically very similar. However, these new species can be differentiated from H. naevius by several morphological traits. Hynobius sematonotos is characterized and discriminated from other species by combination of small body size, a shallow vomerine teeth series with small number of vomerine teeth, small number of upper and lower jaw teeth, relatively long head and snout, and large upper eyelid, relatively short axilla-groin, reddish purple ground color with grayish brown marking on the dorsum, and reddish to bluish gray ventral ground color with relatively large markings varying from pale-white to white. Hynobius oyamai is characterized and discriminated from other species by large body size, moderately deep vomerine teeth series with a medium number of vomerine teeth, large number of upper and lower jaw teeth, relatively wide internarial and long fifth toe, bluish purple ground color sometimes with pale white marking on dorsum. Hynobius sematonotos occurs in Honshu, disjunct from H. naevius and H. oyamai that occur allopatrically in Kyushu.
两种新的溪流繁殖蝾螈物种，即背纹北鲵（Hynobius sematonotos）和大山北鲵（H. oyamai），分别在日本西部的中国地区和九州东北部地区被描述。它们是所谓的黑斑北鲵（H. naevius）种群的成员，在系统发育上与黑斑北鲵、加藤北鲵（H. katoi）和广濑北鲵（H. hirosei）接近，但在基因距离上与它们有很大差异。这些新物种在形态上与黑斑北鲵非常相似，分别被视为黑斑北鲵在中国地区和九州东北部地区的谱系。然而，这些新物种可以通过几个形态特征与黑斑北鲵区分开来。背纹北鲵的特征在于，与其他物种相比，它体型小，犁骨齿列浅且犁骨齿数少，上下颌齿数少，头部和吻部相对较长，上眼睑大，腋窝至腹股沟相对较短，背部呈红紫色且有灰棕色斑纹，腹面底色为红至蓝灰色且有相对较大的斑纹，斑纹从浅白色到白色不等。大山北鲵的特征在于，与其他物种相比，它体型大，犁骨齿列适中且犁骨齿数中等，上下颌齿数多，鼻间距相对较宽且第五趾长，底色为蓝紫色，有时背部有浅白色斑纹。背纹北鲵分布于本州岛，与分布在九州岛异域分布的黑斑北鲵和大山北鲵不连续。
