Karstsinnectes hyalinus
Creators: name: Ge, Jia-Yue
name: Nong, Zheng-Quan
name: Yang, Jian
name: Du, Li-Na
name: Zhou, Jia-Jun
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Cypriniformes
Nemacheilidae
Karstsinnectes
Karstsinnectes hyalinus

description: Karstsinnectes hyalinus (Lan, Yang & Chen, 1996)
Figs 1 A, 3; Table 1
Heminoemacheilus hyalinus Lan, Yang & Chen, 1996, 109–112 (Bao’an Township, Du’an County, Hechi City, Guangxi).
Karstsinnectes hyalinus Luo et al., 2023: 696 (Bao’an Township, Du’an County, Hechi City, Guangxi).
Material examined.
3 ex. China; Guangxi, Hechi City, Du’an County, Bao’an Township, 24.0709 ° N, 107.9027 ° E, 283 m a. s. l. GXNU 94098009 –94098011, 38.9–40.2 mm SL.
Diagnosis.
Karstsinnectes hyalinus can be distinguished from other members of Karstsinnectes based on body-scaled (vs. scaleless). It can be further differentiated from K. anophthalmus by caudal fin forked (vs. truncated); from K. acridorsalis, Karstsinnectes longzhouensis sp. nov., and K. parvus by seven branched dorsal-fin rays (vs. eight in K. acridorsalis and nine in Karstsinnectes longzhouensis sp. nov. and K. parvus).
Description.
Body elongated, head depressed. Body trunk compressed, dorsal profile of head and predorsal profile gradually convex, with maximum body depth in middle of pectoral-fin origin and pelvic-fin origin. After dorsal-fin base, dorsal profile of caudal peduncle convex due to developed caudal adipose keel on upper edge of caudal peduncle. Ventral profile of head straight, slightly convex from pectoral-fin origin to pelvic-fin origin, straight from pelvic-fin origin to caudal-fin base.
Anterior and posterior nostrils adjacent, distance less than posterior nostril diameter, base of anterior nostril tube-shaped and tip not clearly elongated to barbel-like. Eyes absent. Mouth inferior, snout obtuse, upper and lower lips smooth. Three pairs of barbels, inner rostral barbel reaching mouth corner, outer rostral and maxillary barbels reaching anterior margin of interopercle. One specimen with one outer and 12 inner gill rakers on first gill arch.
Dorsal fin with two branched and seven branched rays, distal margin straight, origin slightly anterior to pelvic-fin origin. Pectoral fin with one unbranched and 11 branched rays, pectoral-fin length 66.1 % – 74.8 % of distance between pectoral-fin origin and pelvic-fin origin. Pelvic fin with one unbranched and five branched rays, tip of pelvic fin reaching anus. Anal fin with two unbranched and four branched rays, distal margin straight. Anus abutting anal-fin base. Caudal fin forked, with 11 or 12 branched rays. High caudal adipose keels on upper and lower edges of caudal peduncle, height at most of upper adipose keel nearly 1 / 2 caudal peduncle depth. Caudal peduncle length 102.7 % – 123.1 % of its depth (containing adipose keels). Lateral line and cephalic sensory pores absent. Body covered by scales, except head and thorax.
Coloration.
Whole body translucent, without color pattern. Fin membrane hyaline.
Distribution and habitat.
Known only from the type locality, China; Guangxi, Hechi City, Du’an County, Bao’an, 24.0709 ° N, 107.9027 ° E, 283 m a. s. l. The cave water in which this species resides serves as the only source of drinking water for nearby residents. The decline in its population is primarily attributed to habitat alterations resulting from the extraction of cave water for domestic purposes (Zhang and Cao 2021).
Remarks.
The population of K. hyalinus is extremely small, with its presence currently known only through type specimens collected in 1994, with no additional specimens gathered since. Although the lateral line of K. hyalinus was mentioned in the original description, a re-examination of all type specimens by R. Min, the administrator of the Fish Collection Room, Kunming Natural History Museum of Zoology, Kunming Institute of Zoology, revealed no obvious lateral line pores. Hence, K. hyalinus is described as lacking a lateral line in this study.
description: Published as part of Ge, Jia-Yue, Nong, Zheng-Quan, Yang, Jian, Du, Li-Na & Zhou, Jia-Jun, 2024, Taxonomic revision of the cavefish genus Karstsinnectes (Cypriniformes, Nemacheilidae), with a description of a new species from Guangxi Province, China, pp. 663-673 in Zoosystematics and Evolution 100 (2) on pages 663-673, DOI: 10.3897/zse.100.118061