Bilton David T, Mlambo Musa C
School of Biological and Marine Sciences; University of Plymouth; Drake Circus; Plymouth PL4 8AA; UK; Department of Zoology; University of Johannesburg; PO Box 524; Auckland Park; Johannesburg 2006; South Africa.
Department of Freshwater Invertebrates; Albany Museum; and Department of Zoology and Entomology; Rhodes University; Grahamstown 6140; South Africa.
Zootaxa. 2024 May 9;5448(1):143-150. doi: 10.11646/zootaxa.5448.1.10.
Relictorygmus Seidel, Minoshima, Arriaga-Varela & Fikáček, 2018, the only known African genus of the hydrophilid subfamily Cylominae, currently includes two lentic species from the far southwestern Cape of South Africa. Here Relictorygmus riparius sp. nov. is described, based on specimens collected from wet moss beside a small mountain stream in the Kamiesberg, Northern Cape Province, South Africa, almost 500 km from previously known taxa and the first lotic member of the genus. The new species is compared with the two previously described Relictorygmus, R. trevornoahi Seidel, Minoshima, Arriaga-Varela & Fikáček, 2018 and R. repentinus (Hebauer, 2002) and notes are provided on its ecology at the type locality. This unexpected find suggests that other cylomines may remain undetected in southern Africa, particularly since they can easily be mistaken for species of the morphologically similar, but distantly related, Coelostoma Brullé, 1835.
瑞利特隐鳃金龟属（Relictorygmus）由塞德尔（Seidel）、米诺希马（Minoshima）、阿里亚加 - 瓦雷拉（Arriaga-Varela）和菲卡切克（Fikáček）于2018年发现，是水龟虫亚科西里金龟亚科（Cylominae）中唯一已知的非洲属，目前包括来自南非最西南端开普地区的两种静水物种。本文描述了新物种瑞利特隐鳃金龟（Relictorygmus riparius sp. nov.），其标本采自南非北开普省卡米斯堡一条小山溪旁潮湿的苔藓中，距离此前已知的分类单元近500公里，是该属的首个流水栖息物种。将新物种与之前描述的两种瑞利特隐鳃金龟，即2018年的特雷沃诺阿氏瑞利特隐鳃金龟（R. trevornoahi Seidel, Minoshima, Arriaga-Varela & Fikáček）和雷氏瑞利特隐鳃金龟（R. repentinus (Hebauer, 2002)）进行了比较，并提供了其模式产地的生态记录。这一意外发现表明，非洲南部可能还有其他未被发现的西里金龟亚科物种，尤其是因为它们很容易被误认为是形态相似但亲缘关系较远的1835年布吕勒（Brullé）命名的腔口隐鳃金龟属（Coelostoma）的物种。
