Boonyanusith Chaichat, Wongkamhaeng Koraon, Azman Abdul-Rahim
School of Biology, Faculty of Science and Technology, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima 30000, Thailand Nakhon Ratchasima Rajabhat University Nakhon Ratchasima Thailand.
Department of Zoology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand Kasetsart University Bangkok Thailand.
Zookeys. 2024 Dec 6;1219:303-329. doi: 10.3897/zookeys.1219.133132. eCollection 2024.
A new genus and species of the family Pseudocyclopidae, , was described based on specimens collected using a light trap in the marine cave of Sipadan Island, Sabah, Malaysia. The new genus is most related to , primarily based on the similarity observed in the armament of ancestral segment IV of the male antennules, the armament of the female P5 Exp-3, the segmentation of the male P5, the armament of the maxillular basal exite, and the relative length of the ancestral segment XXVII of the antennules. Nevertheless, it distinguishes itself from and all other genera of the family by the absence of the lateral seta of the basis of all swimming legs, the presence of an inner seta on the coxa of the female P5, the reduction of furcal setae I and III, as well as the specific armament of the ancestral segment XX of the antennules and the maxillular coxal endite. The female of has aesthetascs on the ancestral segments IV and XX of the antennules, as well as six setae on the maxillular coxal endite, exhibiting the most plesiomorphic characteristics of the family Pseudocyclopidae. The latter characteristic has not been recorded in the order Calanoida. It was hypothesised that the new species was a particle feeder living in the pelagic zone of the marine cave. The existence of the new species supported the assumption that the regional distribution of the family Pseudocyclopidae exhibited the Tethyan track, which might have been the subsequent result of the colonisation of the habitats prior to the closure of the Tethys Sea.
基于在马来西亚沙巴州诗巴丹岛海洋洞穴中使用灯光诱捕器收集的标本，描述了伪哲水蚤科的一个新属和新种。这个新属与[属名未给出]最为相关，主要依据是在雄性小触角祖先节段IV的武装、雌性P5外肢-3的武装、雄性P5的分节、小颚基部外叶的武装以及小触角祖先节段XXVII的相对长度方面观察到的相似性。然而，它与[属名未给出]以及该科的所有其他属不同，其所有游泳足基部的外侧刚毛缺失，雌性P5基节上有一根内侧刚毛，尾叉刚毛I和III减少，以及小触角和小颚基节内叶祖先节段XX的特定武装。[新属名未给出]的雌性在小触角的祖先节段IV和XX上有感觉毛，以及小颚基节内叶上有六根刚毛，展现出伪哲水蚤科最原始的特征。后一特征在哲水蚤目中尚未有记录。据推测，新物种是一种生活在海洋洞穴中上层带的颗粒食性者。新物种的存在支持了伪哲水蚤科区域分布呈现特提斯海轨迹的假设，这可能是特提斯海关闭之前栖息地定殖的后续结果。
