Abstract The biodiversity of the deep-sea of the Gulf of California has received some attention during the last two decades. Preliminary observations have revealed a high diversity of benthic and hyperbenthic copepods. Copepods of the genus Rhizothrix were found in sediment samples taken during the Talud X cruise in the Guaymas Basin. These specimens belong to a new species, Rhizothrix longiseta. The new species is related to R. quadriseta Wells, 1967 from Inhaca Island, Mozambique by the armature complement of the third exopodal segment of the second, third and fourth swimming legs, and of the second endopodal segment of the third swimming leg. The females of these two species can be distinguished by the armature complement of the second endopodal segment of the first and second swimming legs, by the relative length of the inner seta on the third exopodal segment of the second, third and fourth swimming legs, by the shape and number of setae on the exopod of the fifth leg, by the length:width ratio of the caudal rami, and by the number of segments of the antennule. This is the first record of the genus Rhizothrix from the deep-sea down to 1570 m depth, and is also the first record of the genus for Mexico. Additionally, R. reducta noodti Galhano, 1970 is given full species rank as R. noodti.

中文翻译：

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来自加利福尼亚湾深海的Rhizothrix属（桡足类：Harpacticoida：Rhizothrichidae）的新记录和新种

摘要 在过去的 20 年里，加利福尼亚湾深海的生物多样性受到了一些关注。初步观察表明底栖和超底栖桡足类的高度多样性。在瓜伊马斯盆地的 Talud X 巡航期间采集的沉积物样本中发现了根茎类桡足类。这些标本属于一个新物种，Rhizothrix longiseta。该新物种与 1967 年来自莫桑比克 Inhaca 岛的 R. quadriseta Wells 有亲缘关系，其第二、第三和第四条游泳腿的第三外足节段以及第三条游泳腿的第二个内足节段的电枢互补。这两个物种的雌性可以通过第一和第二游泳腿的第二内足节的电枢互补来区分，由第二、三、四游足第三外足节内刚毛的相对长度，第五足外足刚毛的形状和数量，由尾支的长宽比，和由触角的节段数决定。这是Rhizothrix属从深海到1570 m深度的第一个记录，也是墨西哥该属的第一个记录。此外，R. reducta noodti Galhano, 1970 的完整物种等级为 R. noodti。也是墨西哥该属的第一个记录。此外，R. reducta noodti Galhano, 1970 的完整物种等级为 R. noodti。也是墨西哥该属的第一个记录。此外，R. reducta noodti Galhano, 1970 的完整物种等级为 R. noodti。