Wednesday, January 18, 2023

[Ichthyology • 2023] Sinocyclocheilus longicornus • A New Species of Microphthalmic Hypogean Fish (Cypriniformes: Cyprinidae) from Guizhou, Southwest China


Sinocyclocheilus longicornus Luo, Xu, Wu, Zhou & Zhou,

in Xu, Luo, Zhou, Wu, Zhao, Yang, Xiao & Zhou, 2023. 

Abstract
Sinocyclocheilus longicornus sp. nov. is described from the Pearl River basin in Hongguo Town, Panzhou City, Guizhou Province, Southwest China. Based on the presence of the long horn-like structure on the back of the head, Sinocyclocheilus longicornus sp. nov. is assigned to the Sinocyclocheilus angularis species group. Sinocyclocheilus longicornus sp. nov. is distinguished from its congeners by a combination of morphological characters: (1) presence of a single, relatively long horn-like structure on the back of the head; (2) pigmentation absent; (3) reduced eyes; (4) dorsal-fin rays, ii, 7; (5) pectoral-fin rays, i, 13; (6) anal-fin rays, iii, 5; (7) pelvic-fin rays, i, 7; (8) lateral line pores 38–49; (9) gill rakers well developed, nine on first gill arch; and (10) tip of adpressed pelvic fin not reaching anus.

Keywords: cave fish, morphology, taxonomy, phylogeny

Lateral view of adult male holotype GZNU20210503002 of Sinocyclocheilus longicornus sp. nov. in preservative. A left side view B right side view.

Live adult male paratype of Sinocyclocheilus longicornus sp. nov. 

 Sinocyclocheilus longicornus Luo, Xu, Wu, Zhou & Zhou, sp. nov.
 
Diagnosis: Sinocyclocheilus longicornus sp. nov. can be distinguished from all other congeners by the following combination of characters: (1) having a single, relatively long horn-like structure on the back of the head; (2) body scaleless, albinotic body without pigmentation; (3) reduced eyes; (4) dorsal-fin rays, ii, 7; (5) pectoral-fin rays, i, 13; (6) anal-fin rays, iii, 5; (7) pelvic-fin rays, i, 7; (8) lateral line pores 38–49; (9) gill rakers well developed, 9 on first gill arch; (10) tip of the pelvic-fin rays not reaching the anus when pelvic-fin rays extended backward.

Etymology: The specific epithet longicornus is an invariable noun in apposition, derived from the Latin words longus, meaning long, and cornu or cornus, meaning horn of the forehead, in reference to the presence of a long horn-like structure on the forehead of the species. We propose the English common name Long-Horned Golden-lined Fish and the Chinese common name Cháng Jiǎo Jīn Xiàn Bā (长角金线鲃).


 Cheng Xu, Tao Luo, Jia-Jun Zhou, Li Wu, Xin-Rui Zhao, Hong-Fu Yang, Ning Xiao and Jiang Zhou. 2023. Sinocyclocheilus longicornus (Cypriniformes, Cyprinidae), A New Species of Microphthalmic Hypogean Fish from Guizhou, Southwest China. ZooKeys. 1141: 1-28. DOI: 10.3897/zookeys.1141.91501