Two new species of the butterflyfish genus Roa (Perciformes: Chaetodontidae)
Two new species of the butterflyfish genus Roa (Perciformes: Chaetodontidae)
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DOI：
10.1111/jfb.14993
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发表时间：
2022-01-27
影响因子：
2
通讯作者：
Motomura，Hiroyuki
中科院分区：
文献类型：
--
作者：
Matsunuma，Mizuki;Motomura，Hiroyuki
本文记述了毛齿鱼科（Chaetodontidae）罗阿属（Roa）两新种：罗阿属（Roa semilunarsp.）十一月，根据来自马斯克林海岭（印度洋西南部）的六个标本，发现的一种新的热带柔鱼与分布于红海和北方印度洋的Roa jayakari（Norman，1939）最为相似，其特征是上颚有鳞片，第二条深色体带内有间断的浅色线条，腹鳍的颜色和形状相似。然而，半月红蜘蛛（R. semilunarissp.）的第二条和第三条黑色带之间的白色间隙较宽[侧线水平处的间隙宽度为标准长度（SL）的15.9%-18.5%]。Nov.（对比贾雅卡里氏蛙SL的5.1%-8.5%）]，间隙中有9或10个有孔侧线鳞片（vs. 3-5）;在背鳍的软射线部分上有一个椭圆形或半圆形的单眼斑（vs.圆形斑点）;头高而长[头长为SL的35.0%-36.7（vs. SL的40.8%-44.1%），头高SL的48.1%-50.5%（vs. SL的52.0%-56.9%）]，眶后长SL的14.0%-15.1%（vs. SL的17.0%-20.5%）。十一月，根据三个来自关岛的标本（马里亚纳群岛），是最类似于Roa excelsa（约旦，1921年）（现在仅限于夏威夷群岛和约翰斯顿岛），但与后者的区别是有一个圆形的背鳍单眼斑（与后者明显椭圆形的斑点相比）和更细长的丝状第一腹鳍软条，第二条射线长度的119.0%-123.4%（与不明显的丝状相比，104.9%-105.8%）。提供了八个有效种的检索表。
Two new species ofRoa(Chaetodontidae) are described.Roa semilunarissp. nov., based on six specimens from the Mascarene Ridge (south‐western Indian Ocean), is most similar toRoa jayakari(Norman, 1939), distributed in the Red Sea and the northern Indian Ocean, in having scales on the upper jaw, interrupted pale lines within the second dark body band, and similar coloration and shape of the pelvic fin. However, the former is readily distinguished fromR.jayakariby a wider whitish interspace between the second and third black bands [width of interspace at lateral line level 15.9%–18.5% of standard length (SL) inR.semilunarissp. nov. (vs. 5.1%–8.5% of SL inR.jayakari)], with 9 or 10 pored lateral‐line scales in the interspace (vs. 3–5); an oval or semicircular ocellated blotch on the soft‐rayed portion of the dorsal fin (vs. a circular blotch); the head higher and longer [head length 35.0%–36.7% of SL (vs. 40.8%–44.1% of SL), head height 48.1%–50.5% of SL (vs. 52.0%–56.9% of SL)], and postorbital length 14.0%–15.1% of SL (vs. 17.0%–20.5% of SL).Roa uejoisp. nov., based on three specimens from Guam (Mariana Islands), is most similar toRoa excelsa(Jordan, 1921) (now restricted to the Hawaiian Islands and Johnston Island), but is distinguished from the latter by having a circular dorsal‐fin ocellated spot (vs. spot distinctly oval in the latter) and a much more elongate, filamentous first pelvic‐fin soft ray, of length 119.0%–123.4% of 2nd ray (vs. not obviously filamentous, 104.9%–105.8%). A key to the eight valid species ofRoais provided.