Pareuchiloglanis (Teleostei: Sisoridae) from the Pearl River, China with description of three new species

Abstract

We describe three new species of Pareuchiloglanis. Based on a comparison of 17 valid species of Pareuchiloglanis, the genus can be divided into two groups contingent on their gill opening size and the anus position. One group, which we call the large gill opening group, has a large gill opening extending to the base of the first pectoral‐fin element; the anus is obviously closer to pelvic‐fin insertion than the anal‐fin origin; this group includes five species distributed in the Red and Pearl Rivers, China. The other group has a small gill opening extending only to the middle base of the pectoral‐fin elements; the anus is usually located at the midpoint of the pelvic‐fin insertion to the anal‐fin origin or slightly behind. This group includes the other 12 species, which are distributed in the Mekong and Yangtze Rivers. The large‐gill‐opening group can be divided into two sub‐groups based on the length of the caudal peduncle. One sub‐group has a long caudal‐peduncle and the distance from the anal‐fin origin to caudal‐fin base is greater than distance from the pelvic‐fin insertion. This sub‐group is only distributed in the Pearl River drainage. Another sub‐group has a short caudal peduncle and the distance from the anal‐fin origin to the caudal‐fin base is typically smaller than the distance from the pelvic‐fin insertion. This sub‐group is only distributed in the Red River basin of China and Vietnam. The former will be called the large‐gill‐opening group with long caudal peduncle in the text and only includes one species P. longicauda. During our ongoing taxonomic work of specimens collected from Nanpan‐jiang and Beipan‐jiang (upper Pearl River drainage in Yunnan, China), some Pareuchiloglanis specimens that had the characters of the large‐gill‐opening group with long caudal peduncle represent three undescribed species.

Eight in One: Hidden Diversity of the Bagrid Catfish Tachysurus albomarginatus s.l. (Rendhal, 1928) Widespread in Lowlands of South China

“…South China lies within the Asian subtropical region with an affluent diversity of freshwater fish species ( Du et al, 2021 ). In stark contrast to the high amount of conservation attention currently given to the highlands of South China, including the upper Yangtze River (= Chang-Jiang in Chinese) and upper Pearl River (=Zhu-Jiang in Chinese) basins, which have high numbers of endemic and threatened fishes ( Dao et al, 2020 ), little or no efforts have been made to protect the non-charismatic fish species of the lowlands of South China such as the mid-lower Chang-Jiang and Zhu-Jiang basins, likely due to a lower level of endemism. However, several widespread freshwater fishes from these lowland areas have been shown to represent multiple distinct genetic lineages by using phylogenetic analysis ( Perdices et al, 2005 ; Yang et al, 2016 ; Chen et al, 2017 ), therefore justifying a need to reassess the morphologically based widespread species under a molecular scrutiny.…”

Type locality and species identity of Pareuchiloglanis sinensis (Hora & Silas) with a description of a new species of the genus from the upper Yangtze River basin in southern China

“…Counts and measurements were taken from the left side of the specimens when possible and were performed as described in a previous study (Dao et al ., 2019) using the methods in Ng and Kottelat (1999), Ng (2004) and Zhou et al . (2011a, 2011b).…”

“…Moreover, the vertebra number was observed using X‐ray photography (Xpeart 80, Kubtec, Stratford, CT; https://www.kubtec.com). Then, the number of vertebra was expressed as thoracic vertebra (centrum connecting with rib) number + caudal vertebra number ( n ) (Dao et al ., 2019).…”

“…The genus Pareuchiloglanis (Sisoridae, Siluriformes), distributed in the Salween, Mekong, Red, Pearl and Yangtze River basins in China, Laos, Myanmar and Vietnam (Dao et al ., 2019; Fricke et al ., 2020; Kottelat, 2013; Zhang et al ., 2016), consists of 20 valid species and 5 uncertain species (Kottelat, 2013), namely Pareuchiloglanis brevicaudatus Nguyen (2005), Pareuchiloglanis dorsoarcus (Nguyen 2005), Pareuchiloglanis namdeensis Nguyen (2005), Pareuchiloglanis phongthoensis (Nguyen 2005) and Pareuchiloglanis tamduongensis Nguyen (2005). All species with an uncertain taxonomic status occur in Laizhou, northern Vietnam (Nguyen & Nguyen, 2005), which is close to southern Yunnan Province, China.…”

“…Thus, it is unclear whether the specimens from the Jinsha‐jiang drainage identified as P. sinensis accurately represented E. sinensis Hora and Silas (1952). Recently, while investigating Pareuchiloglanis from the Nanpan‐jiang basin (the upper Pearl River drainage, China) (Dao et al ., 2019), the authors collected specimens with morphological characteristics similar to the original description of E. sinensis .…”