Invertebrates are exceptionally diverse, but many are in decline because of anthropogenic changes to their habitat. This situation is particularly problematic for taxa that are not well monitored or taxonomically poorly understood, because the lack of knowledge hampers conservation. Despite their important functional role in freshwater ecosystems, African bivalves of the family Unionidae remain poorly studied compared to their highly threatened relatives in Europe, the U.S.A. and Canada. To resolve relationships and to study diversification dynamics in space and time, we performed time-calibrated phylogenetic studies and biogeographical modeling on the unionids from the East African Rift System and surroundings, including representatives of all currently recognized Afrotropical genera except for Brazzaea (and Unio from southern Africa). Our analyses indicate that all sampled Afrotropical unionids belong to the tribe Coelaturini (subfamily Parreysiinae), as does the genus Moncetia from Lake Tanganyika, which is currently attributed to the family Iridinidae. Colonization of Africa from Eurasia by Parreysiinae occurred ~17 Ma ago, and the subsequent diversification of Coelaturini in Africa continued at a steady pace, although net diversification decreased over time as more niches and ecoregions became occupied. Clades in Coelaturini largely reflect drainage basins, with the oldest lineages and highest regional diversity occurring in Lake Tanganyika, followed by the Congo Basin watershed in general. The species assemblage of Lake Tanganyika reflects multiple independent events of colonization and intralacustrine diversification since the Late Miocene or Early Pliocene. The clades of other regions, including that containing the species from Lake Malawi, are comparatively young. Biogeographical analyses indicate that the colonization history was mainly driven by cladogenesis in sympatry, whereas few anagenetic events contributed to the modern distribution of Coelaturini. Ancestral range estimations demonstrate that Coelaturini originated in the Victoria and/or Tanganyika ecoregions, and that the Congo Basin played an essential role in the colonization of Africa by Coelaturini.

中文翻译：

---

淡水双壳类动物的多样性动态（Unionidae：Parreysiinae：Coelaturini）表明了整个东非裂谷系统的历史水文联系。

无脊椎动物种类繁多，但由于栖息地的人为改变，许多无脊椎动物正在减少。对于这种情况，对于缺乏良好监控或分类学上不太了解的分类单元而言，这尤其成问题，因为缺乏知识会妨碍保护。尽管它们在淡水生态系统中起着重要的作用，但与欧洲，美国和加拿大受威胁程度较高的亲戚相比，Unionidae家族的非洲双壳类动物仍然研究较少。为了解决关系并研究时空的多样性动态，我们对东非大裂谷系统和周围环境的虫体进行了时间校准的系统发育研究和生物地理建模，包括除了Brazzaea（以及来自非洲南部）。我们的分析表明，所有采样到的非裔工会联合体都属于Coelaturini部落（Parreysiinae子家族），而坦ika尼喀湖的Moncetia属也属于该部落，目前归因于Iridinidae家族。Parreysiinae在欧亚大陆对非洲的殖民化发生在大约17 Ma之前，随后非洲Coelaturini的多样化继续保持稳定的速度，尽管随着时间的推移，更多利基和生态区被占领，净多样化减少了。Coelaturini的进化枝主要反映了流域盆地，坦ika尼喀湖的血统最古老，区域多样性最高，其次是刚果盆地的分水岭。坦any尼喀湖的物种聚集反映了中新世晚期或上新世以来的多次独立的殖民化和湖内变化事件。其他地区的进化枝，包括那些来自马拉维湖的物种，则相对较年轻。生物地理学分析表明，定殖的历史主要由共生中的枝条形成驱动，而很少的镇痛事件促进了腔骨的现代分布。祖传范围的估计表明，腔el鱼起源于维多利亚和/或坦any尼喀生态区，刚果盆地在腔el鱼对非洲的殖民化中发挥了重要作用。