Patterns of Diversity, Areas of Endemism, and Multiple Glacial Refuges for Freshwater Crabs of the Genus Sinopotamon in China (Decapoda: Brachyura: Potamidae)

Abstract

Previous research has shown that the geographical distribution patterns of freshwater fishes and amphibians have been influenced by past climatic oscillations in China resulting from Pleistocene glacial activity. However, it remains unknown how these past changes have impacted the present-day distribution of Chinese freshwater crabs. This work describes the diversity and endemism of freshwater crabs belonging to Sinopotamon, a highly speciose genus endemic to China, and evaluates its distribution in terms of topography and past climatic fluctuations. Species diversity within Sinopotamon was found to be concentrated in an area from the northeastern edge of the Yunnan-Guizhou Plateau to the Jiangnan Hills, and three areas of endemism were identified. Multiple regression analysis between current climatic variables and Sinopotamon diversity suggested that regional annual precipitation, minimum temperature in the coldest month, and annual temperature range significantly influenced species diversity and may explain the diversity patterns of Sinopotamon. A comparison of ecological niche models (ENMs) between current conditions and the last glacial maximum (LGM) showed that suitable habitat for Sinopotamon in China severely contracted during the LGM. The coincidence of ENMs and the areas of endemism indicated that southeast of the Daba Mountains, and central and southeastern China, are potential Pleistocene refuges for Sinopotamon. The presence of multiple Pleistocene refuges within the range of this genus could further promote inter- and intraspecific differentiations, and may have led to high Sinopotamon species diversity, a high endemism rate and widespread distribution.

Evolutionary history of the scorpionfly Dicerapanorpa magna (Mecoptera, Panorpidae)

“…TMRCA is estimated at 0.65 and 0.83 Ma for Lineages II and III, respectively, and is 1.07 Ma for Lineage I, both roughly correlated with the Kunlun‐Yellow River movement from 1.10 to 0.60 Ma (Cui et al, ). The population diversification and species distribution in D. magna have been deeply influenced by the Pleistocene tectonic movements and climatic fluctuations, as noted in a ring‐necked pheasant (Qu et al, ), a toad‐headed lizard gecko (Yan et al, ), frogs (Wang, Jiang, Xie, & Li, ; Yan et al, ), freshwater crabs (Fang et al, ), a geometrid moth (Cheng et al, ) and a salamander (Huang et al, ).…”

Evolutionary melting pots and reproductive isolation: A ring‐shaped diversification of an odorous frog (Odorrana margaratea) around the Sichuan Basin

“…Furthermore, all cyt-b haplotypes from the eastern region grouped together on the network and demonstrated limited sharing with other regions. The Shennongjia (site 5) and surrounding area, which is part of the Daba Mountains, is also a well-known glaciation refugium (e.g., Fang et al, 2013;Wang, Jiang, Xie, & Li, 2012), and preserves several "living fossil" species (e.g., Davidia involucrata). Nevertheless, multiple refugia or multiple microrefugia in a refugium (de Lafontaine, Amasifuen Guerra, Ducousso, -Goñi, & Petit, 2014;Qu et al, 2011) Not all evidence is consistent with the two-refugia hypothesis.…”

Rapid divergent coevolution of Sinopotamon freshwater crab genitalia facilitates a burst of species diversification

“…Sinopotamon is the most species-rich genus of freshwater crabs in China and is the group with the largest geographic distributional range in this global biodiversity hotspot (Dai 1999;Yeo et al 2008;Cumberlidge et al 2009Cumberlidge et al , 2011Fang et al 2013;Chu et al 2018). The striking morphological variation of the male G1 in species of Sinopotamon has been used as a high-weight character in systematic classification (Dai 1999;Chu et al 2018).…”