Description of a new loach species, Yunnanilus triangulus sp. nov. (Cypriniformes, Nemacheilidae), from Yunnan, China

By

Liu, Mei
Lyu, Jian-Bing
Du, Li-Na
Chen, Xiao-Yong

Type

Article

Date of Publication

2025-2-26

Original Publication

Zoosystematics and evolution

Volume

101

Series / Issue

Issue: 2

Pages

465--471

Subjects

Caudal peduncle with tubercles , freshwater fish , morphological characters , sexual dimorphism

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft

Identifiers

DOI: https://doi.org/10.3897/zse.101.136965

 

Abstract

A new species of the genus Yunnanilus, designated Yunnanilus triangulussp. nov., is described from the Nanpan River in Yunnan Province, southwestern China. Nuptial males of this species are distinguished by the presence of tubercles on the caudal peduncle during the reproductive period, a feature not observed in other members of the genus. The new species is further characterized by the following unique combination of morphological characters: body scaled, smaller eyes than interorbital width, nine inner gill rakers on first gill arch, lateral head length 27.1%–30.9% SL, head width 14.3%–17.2% SL, eye diameter 19.6%–23.8% of lateral head length, and caudal peduncle depth 94.0%–130.6% of its length. Morphological and molecular evidence support the validity of this species, despite its geographic proximity to Y. polylepis. These findings underscore the ecological specialization that exists within the genus Yunnanilus and highlight the urgent need for species-specific conservation strategies, given their restricted distributions and dependence on specific habitats.