Environment and Energy Systems, Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka City, 422-8529 Japan..
Zootaxa. 2022 May 12;5134(4):569-587. doi: 10.11646/zootaxa.5134.4.5.
This study is designed to evaluate the male copulatory organs and carapace size of the inner bay benthic ostracod Bicornucythere bisanensis. The male copulatory organs demonstrate noticeable intraspecific variation in the distal lobe, especially the length of the tip, which shows a gradual variation; whereas the thickness of the distal lobe is conservative within the species. The population from central Japan (Aburatsubo Cove) showed remarkable morphological variations, with four copulatory organ types, each type defined by a combination of four shapes of the right and left distal lobes (Shape R, r, L, and l). While the variety of carapace morphotypes have been previously reported, our findings suggest that one morphotype from western Japan (Misumi-cho) should be treated as a distinct species. Thus, we described it as Bicornucythere misumiensis sp. nov.
本研究旨在评估内湾底栖介形虫 Bicornucythere bisanensis 的雄性交配器官和甲壳大小。雄性交配器官在远端裂片上表现出明显的种内变异，特别是尖端的长度，呈现出逐渐变化的趋势；而远端裂片的厚度在种内是保守的。来自日本中部（浦洼湾）的种群显示出显著的形态变异，有四种交配器官类型，每一种类型都是由左右远端裂片的四种形状（形状 R、r、L 和 l）组合定义的。虽然以前已经报道了甲壳形态型的多样性，但我们的研究结果表明，来自日本西部（三美町）的一种形态型应该被视为一个独特的物种。因此，我们将其描述为 Bicornucythere misumiensis sp. nov.
