Revision of the Cyprinid Genus Crossocheilus (Tribe Labeonini) with Description of a New Species
The Southeast Asian cyprinid genus Crossocheilus was briefly described by Kuhl and van Hasselt in 1823 and, despite the short description, has remained a valid genus. However, the genus and its species are frequently misidentified in institutional collections, likely due to the absence of a detailed diagnosis and description, as well as the superficial morphological similarity with other cyprinid genera in the region. Crossocheilus and its constituent species are herein revised based on an examination of morphology and pigmentation. Eleven species are recognized, including a new species described from Indonesia. Crossocheilus pseudobagroidesis a junior synonym of C. langei. Crossocheilus tchangi is removed from synonymy with C. reticulatus and is a senior synonym of C. stigmaeus. Phylogenetic relationships among species of Crossocheilus based on sequences from the nuclear encoded recombination activating gene 1 are reconstructed. The resultant phylogeny is the most taxonomically comprehensive estimation of relationships among Crossocheilus to date and resolves C. atrilimes and C. oblongus, previously hypothesized to be sister species, not to be most closely related to one another.
Phylogeny of Crossocheilus based on Bayesian analysis of RAG1, with posterior probability values at nodes.
Ventral views of heads of (A) Crossocheilus atrilimes, UF 185188, 79.9 mm SL, and (B) C. microstoma, new species, BMNH 1982.3.29.1, 80.7 mm SL. Abbreviations: l, length of lower lip; LL, lower lip; MB, maxillary barbel; RB, rostral barbel; RC, rostral cap; RL, rostral lobe; UL, upper lip; w, width of lower lip. Images not to scale.
Crossocheilus atrilimes, UF 173139, 62.8 mm SL. Photo by Z. Randall (FLMNH).
Distributions of georeferenced specimens examined of: (A) Crossocheilus atrilimes, (B) C. cobitis and C. microstoma, (C) C. elegans and C. nigriloba, and (D) C. gnathopogon and C. langei. Syntypes of C. cobitis plotted at Padang, Sumatra (0.9471S, 100.4172E) and Jakarta, Java (6.2088S, 106.8456E). Syntypes of C. nigriloba plotted on the Bo River in East Kalimantan, Borneo (1.1817N, 115.1156E). Lectotype of C. gnathopogon plotted at Bukittinggi, Sumatra (0.3039S, 100.3835E). Holotype of C. langei plotted at Palembang, Sumatra (2.9761S, 104.7754E).
Crossocheilus cobitis, BMNH 2000.10.25.736, 31.8 mm SL. Photo by Z. Randall (FLMNH).
Crossocheilus elegans, FMNH 68502, 65.6 mm SL.
Crossocheilus gnathopogon, ZMA 113745, lectotype, 91.6 mm SL. Photo by R. de Ruiter (RMNH).
Crossocheilus langei. (A) BMNH 1866.5.2.106, holotype, 59.3 mm SL, (B) ZRC 44175, 98.7 mm SL. Photo A by J. Maclaine (BMNH); photo B by H. H. Tan (LKCNHM).
Crossocheilus microstoma, USNM 230159, holotype, 74.9 mm SL: (A) lateral view, (B) ventral view.
Crossocheilus nigriloba, CAS 94551, 63.1 mm SL.
Crossocheilus oblongus, UF 173140, 80.9 mm SL. Photo by Z. Randall (FLMNH).
Distributions of georeferenced specimens examined of: (A) Crossocheilus oblongus, (B) C. obscurus, (C) C. reticulatus, and (D) C. tchangi. Lectotype of C. oblongus plotted in Java (6.5972S, 106.806E). Holotype of C. reticulatus plotted at Bua Yai District, Thailand (15.5702N, 102.3922E).
Crossocheilus obscurus, UF 162186, 44.7 mm SL.
Crossocheilus reticulatus, UF 185185, 61.1 mm SL.
Crossocheilus tchangi. (A) ANSP 61690, holotype, 129.4 mm SL, (B) USNM 109765, holotype of Epalzeorhynchos stigmaeus, 93.6 mm SL, (C) UF 236093, 50.3 mm SL. Photo A by K. Luckenbill (ANSP); photo B by S. Raredon (USNM).
Contributor Notes
Associate Editor: D. Buth.