New Bathynellidae (Crustacea) taxa and their relationships in the Fortescue catchment aquifers of the Pilbara region, Western Australia

In the past 20 years, the number of subterranean taxa discovered in Australia, especially in the Pilbara bioregion, has considerably increased due to incidental environmental surveys often associated with mining development. Bathynellidae are an important component of stygofauna and they occur in most Australian aquifers, but their collection and identification are difficult due to their habitat, and small and fragile bodies with conservative morphology. The study of <i>Pilbaranella ethelensis</i> in the upper Fortescue catchment contributed to a better understanding of the group at local scale, but knowledge at larger catchment scale is still limited. Abundant material collected by different environmental consultant companies on behalf of mining companies allowed an accurate analysis of the populations of Central Hamersley Range bathynellids. A new genus and one new species from the lower Fortescue catchment, <i>Fortescuenella serenitatis</i> gen. et sp. nov., is described using an approach that integrates morphological and molecular data. Three additional lineages are defined through morphology and DNA sequencing, using Automatic Barcode Gap Discovery and Poisson Tree Processes species delimitation methods. Based on previous knowledge on bathynellids and other stygofauna we expected to find multiple taxa, geographically restricted, possibly related to each other and to <i>Pilbaranella</i> genus described upstream of the Fortescue catchment. The phylogenetic reconstruction of the relationships among known lineages of the family in the Pilbara highlights a pattern of distribution characterized by a complex evolutionary history that does not reflect contemporary surface water catchments, suggesting a diversification that preceded the aridification processes started in the north of Western Australia during the Miocene. This study also clarifies the status of the 'cosmopolitan' <i>Bathynella</i> by excluding the Australian bathynellids from this genus. http://www.zoobank.org/urn:lsid:zoobank.org:act:E30796F4-1026-4278-BC13-45091DCB44CC

过去二十年间，得益于常与矿业开发相关的偶然环境调查，澳大利亚，尤其是皮尔巴拉生物区（Pilbara bioregion），发现的地下类群（subterranean taxa）数量显著增加。
山虾科（Bathynellidae）是地下水生动物群（stygofauna）的重要组成类群，广泛分布于澳大利亚多数含水层中，但因其栖息环境、体型微小且躯体脆弱、形态保守，采集与鉴定难度极大。
针对福尔蒂斯科河上游集水区的<i>Pilbaranella ethelensis</i>的研究，增进了我们对该类群在局域尺度下的认知，但大集水区尺度的相关知识仍较为匮乏。
多家环境咨询公司受矿业企业委托采集的大量标本，使得我们能够精准分析哈默斯利山脉中部的山虾科类群种群。
本研究整合形态学与分子数据，描述了来自福尔蒂斯科河下游集水区的1个新属及1个新种——<i>Fortescuenella serenitatis</i> gen. et sp. nov.。
本研究通过形态学与DNA测序，结合自动条形码间隙发现法（Automatic Barcode Gap Discovery）与泊松树状过程物种界定法（Poisson Tree Processes），界定了3个额外的演化支系。
基于此前对山虾科及其他地下水生动物类群的认知，我们预期会发现多个地理受限、彼此间可能存在亲缘关系，且与福尔蒂斯科河上游集水区所描述的<i>Pilbaranella</i>属相关的类群。
对皮尔巴拉地区山虾科已知演化支系间亲缘关系的系统发育重建结果显示，其分布模式具有复杂的演化历史，且并未与现代地表水系集水区相契合，这表明该类群的物种分化早于中新世时期西澳大利亚北部开始的干旱化进程。
本研究同时澄清了“广布性”的<i>Bathynella</i>属的分类地位，将澳大利亚的山虾科类群移出该属。
http://www.zoobank.org/urn:lsid:zoobank.org:act:E30796F4-1026-4278-BC13-45091DCB44CC