Landschoff Jannes, Lemaitre Rafael
Department of Biological Sciences and Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa.
Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, 4210 Silver Hill Road, Suitland, MD 20746, U.S.A.
Zookeys. 2017 May 23(676):21-45. doi: 10.3897/zookeys.676.12987. eCollection 2017.
Deep-water hermit crabs of the family Parapaguridae can be abundant (up to 20 kg or 1000 hermit crab individuals per haul) in the trawl bycatch collected during South African demersal abundance research surveys. Until recently, only two parapagurid species had been recognized in the bycatch; Stebbing, 1910, and (Studer, 1883). Detailed examination of numerous samples of parapagurid specimens from research surveys revealed the existence of a third, undescribed species previously confounded with , but in fact belonging to a different genus. This new species, is the 25 in the genus Lemaitre, 1996, and has been found only in a small region on the West Coast shelf of South Africa, at depths of 199-277 m. The species is herein fully described and illustrated, including colour images, µCT scans of selected body parts, and CO1 barcode data. The new species is morphologically most similar to Lemaitre, 2004, a species associated with hydrothermal vents, but differs in armature of the fourth antennal segment (armed with a spine on the dorsolateral distal angle vs. unarmed in ); setation of the antennal flagella (nearly naked vs. with dense setae in ); plumose setation on the third maxillipeds and basal segments of chelipeds (absent vs. present in ); number of rows of scales on the propodal rasp of pereopod 4 (two or three rows vs. one row in ); and degree of telson asymmetry (weakly asymmetrical vs. strongly asymmetrical in ). is superficially similar to , with males of the two species showing the same extreme degree of sexual dimorphism on the right cheliped, general light orange colouration, and frequent use of colonial zoanthid carcinoecia for pleonal protection. To aid in future identifications and to facilitate data gathering during surveys, a comparison of with is provided, along with descriptions of colouration and photographs of live specimens of all three parapagurid species. Information on taxonomy of the species is summarized, as well as knowledge of their distribution in the demersal research survey regions of South Africa.
拟寄居蟹科的深水寄居蟹在南非底栖生物丰度研究调查期间收集的拖网兼捕物中数量可观（每次拖网可达20千克或1000只寄居蟹个体）。直到最近，在兼捕物中仅识别出两种拟寄居蟹物种；即斯特布氏拟寄居蟹（Stebbing，1910年）和（施图德氏拟寄居蟹，Studer，1883年）。对研究调查中大量拟寄居蟹标本样本的详细检查发现，存在第三种未描述的物种，该物种之前与混淆，但实际上属于不同的属。这个新物种，是1996年勒梅特尔属（Lemaitre）中的第25个物种，仅在南非西海岸陆架的一个小区域被发现，深度为199 - 277米。本文对该物种进行了全面描述和图示，包括彩色图像、选定身体部位的µCT扫描以及CO1条形码数据。这个新物种在形态上与2004年的勒梅特尔拟寄居蟹最为相似，后者与热液喷口有关，但在第四触角节的武装（背外侧远角有一根刺与无武装）、触角鞭节的刚毛分布（几乎无毛与有密集刚毛）、第三颚足和螯足基部节上的羽状刚毛（无与有）、第四步足腕节锉上的鳞片排数（两排或三排与一排）以及尾节不对称程度（弱不对称与强不对称）方面存在差异。与表面相似，这两个物种的雄性在右螯足上表现出相同程度的极端性二态性、一般为浅橙色以及频繁使用群体海葵作为腹部保护。为了便于未来的识别并促进调查期间的数据收集，提供了与的比较，以及所有三种拟寄居蟹物种的颜色描述和活体标本照片。总结了该物种的分类学信息以及它们在南非底栖生物研究调查区域的分布情况。
