Biodiversity surveys reveal eight new species of freshwater crabs (Decapoda: Brachyura: Potamidae) from Yunnan Province, China

Abstract

Yunnan Province is known to host the highest species diversity of the true freshwater crabs in China; 50 species have been recorded from the province by 2017. In 2004, our team conducted a biodiversity survey of the freshwater crabs in Yunnan Province to determine how well the diversity of crabs in the area has been characterized. We collected a total of 25 species, of which nine species proved to be new to science, and eight of which are described here. These include four species of the genus Indochinamon Yeo & Ng, 2007, two species of the genus Potamiscus Alcock, 1909, and one species each of the genera Pararanguna Dai & Chen, 1985, and Parvuspotamon Dai & Bo, 1994. The new species of Pararanguna and Parvuspotamon represent the second species of respective genera, which are here redefined. Detailed comparisons with morphologically allied species are provided. Photographs of the type specimens of their comparative species which are poorly illustrated in the literature are also provided to allow better understanding of their morphology. This study brings the number of the freshwater crabs of Yunnan Province to 58. Since about 13.8% of the number of species (eight out of 58 species) is increased by surveys conducted within a relatively short period, it is most probable that the species diversity of this group is still understudied in Yunnan Province.

On a new species of freshwater crab, Indochinamon khinpyae, from northern Myanmar (Crustacea, Brachyura, Potamidae)

“…The other species have G1 terminal segments which are slender, elongate, and straight or curved; or relatively short and strongly bent (cf. Ng and Naiyanetr 1993; Dai 1999; Do et al 2016; Naruse et al 2018; unpublished data). The G1 of I.khinpyae closely resembles that of I.changpoense and I.daweishanense (both from Yunnan) but these two species have only a shallow cleft on the outer margin of the subdistal part of the subterminal segment, and the terminal segment is proportionately shorter and straighter (Dai 1999: figs 85–4, 5; 87–4, 5), even though the types are comparable in size to the holotype of I.khinpyae .…”

“…The type species, I.villosum , has a relatively short and stout G1 terminal segment which is gently bent and is conical to subconical in shape without an obvious dorsal flap, a character shared with I.ahkense , I.bavi , I.bhumibol , I.boshanense , I.changpoense , I.chinghungense , I.dangi , I.daweishanense , I.flexum , I.guttum , I.jianchuan , I.jinpingense , I.kimboiense , I.menglaense , I.mieni , I.orleansi , I.ou , I.parpidum , I.phongnha , I.tannanti , I.xinpingense , and I.yunlongense (including I.edwardsii and I.hispidum ) (cf. Bott 1970; Yeo and Ng 1998; Dai 1999; Naruse et al 2011, 2018; unpublished data). The other species have G1 terminal segments which are slender, elongate, and straight or curved; or relatively short and strongly bent (cf.…”

“…The genus currently contains 38 species from Thailand, Vietnam, Laos, Myanmar, India and China (Table 1, updated from Ng et al 2008; Naruse et al 2018). Established by Yeo and Ng (2007) for Indochinese species previously placed in Potamon Savigny, 1816, s. lato, Indochinamon is defined by a suite of characters: carapace low with a relatively flat dorsal surface; the epigastric cristae are separated from the postorbital cristae by a distinct groove; the postorbital cristae is not confluent with the epibranchial tooth; the exopod of the third maxilliped has a long flagellum; the ambulatory legs are relatively short and stout; the male pleon is narrowly triangular; the sternopleonal cavity reaches an imaginary line joining the median parts of the coxae of the chelipeds; and the G1 terminal segment is relatively short, with the groove for the G2 marginal in position, and the dorsal flap is either absent or only low and broad.…”

A new species of freshwater crab of the genus Qianguimon Huang, 2018 (Decapoda: Brachyura: Potamidae) from Guangxi, Southern China

“…China is the global center of freshwater crab diversity, it has the richest number of freshwater crab species in the world, with more than 300 species from 48 genera and two subfamilies with many more to be discovered (Dai, 1999;Yeo et al, 2008;Cumberlidge et al, 2011;Huang, Shih & Ahyong, 2018;Huang, Wong & Ahyong, 2018;Naruse, Chia & Zhou, 2018;Wang, Huang & Zou, 2019;Wang, Zhou & Zou, 2019). Also, more than 90% of China's freshwater crab species are distributed in the "China" freshwater zoogeographical subregion Huang, Ebach & Ahyong, 2020).…”

Peer Review #1 of "A new species of freshwater crab of the genus Qianguimon Huang, 2018 (Decapoda: Brachyura: Potamidae) from Guangxi, Southern China (v0.2)"

“…China is the global centre of freshwater crab diversity, it has the richest number of freshwater crab species in the world, with more than 300 species from 48 genera and 2 subfamilies with many more to be discovered (Dai, 1999;Yeo et al, 2007;Cumberlidge et al, 2011;Huang, Shih & Ahyong, 2018;Huang, Wong & Ahyong, 2018;Naruse, Chia & Zhou, 2018;Wang, Huang & Zou, 2019;Wang, Zhou & Zou, 2019). And more than 90 percent of China's freshwater crab species are distributed in the "China" freshwater zoogeographical subregion Huang, Ebach & Ahyong, 2020).…”