Cirrhimuraena taiwanensis Lin, Lin & Han, 2025, sp. nov.
Creators: name: Lin, Yen-Ting
name: Lin, Yu-Hsiang
name: Han, Yu-San
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Anguilliformes
Ophichthidae
Cirrhimuraena
Cirrhimuraena taiwanensis

description: Cirrhimuraena taiwanensis sp. nov.
Figs 1, 2, 3, 4, Table 2
Material examined.
Holotype: Taiwan • ASIZP 0082637, 178.1 mm total length (TL); Yilan; 24.7162 ° N, 121.8352 ° E; 22 Dec. 2023; caught by fyke net, ca 1 m, Yu-San Han & Yen-Ting Lin leg.
Diagnosis.
A new Cirrhimuraena species with the combination of following characteristics: pectoral fin very small, only 15.2 % of head length (HL) (in congeners> 21 % HL); HK 9.7 % of TL dorsal fin originates 1 ½ pectoral-fin length behind gill opening; tooth pattern unique, with only a single row of mandibular teeth; cirri on upper jaw 11; vertebrae 150, vertebral formula 13-53 - 150.
Description.
The morphometric and meristic measurements of the holotype are shown in Table 2. Body very elongate, cylindrical; body height is almost consistent from gill opening to anus, with depth at gill opening of 2.2 % of TL and depth at anus of 2.3 % of TL. Head moderate, with head length (HL) 9.7 % of TL. Tail longer than trunk, 63.6 % of TL. Anal fin low, situated right after anus, with pre-anal length 36.8 % of TL. Dorsal fin also low, originating far behind gill opening and pectoral fin; pre-dorsal length 13.2 % of TL. Pectoral fin very small, 15.2 % of HL, 1.5 % of TL; pectoral-fin base positioned at same vertical as gill opening; gill opening positioned on latero-ventral side, length 16.4 % of HL.
Eye relatively large, positioned nearer to snout tip than rictus; eye diameter 8.9 % of HL; interorbital space slightly wider; interorbital length 6.1 % of HL. Anterior nostril tubular, positioned at snout tip, while posterior nostril lies slightly behind orbit. Snout long, pointed, 19.1 % of HL. Upper jaw longer than lower jaw, 35.7 % and 26.9 % of HL, respectively.
Five small cirri on edge of upper jaw between anterior and posterior nostrils; 6 cirri behind posterior nostril. No cirri on lower jaw and tip of jaw in front of nostrils. Dentition pattern illustrated in Fig. 3. Teeth numerous, closely arranged in a band, and primarily small and pointed, with slightly larger teeth at ends. Vomerine teeth in 1–3 rows, extending to posterior of maxilla; 5 teeth form a small patch at prevomer. Maxillary teeth in 2–6 rows of small, conical teeth; mandibular teeth band in only a single row on both sides. Pre-dorsal vertebrae 13, pre-anal vertebrae 53, and total vertebral 150.
Head pores tiny and indistinct, with supraorbital pores 1 + 3, infraorbital pores 3 + 2, preoperculomandibular pores 7 + 4, and supra-temporal pores 1 (Fig. 4). Lateral line pores before pectoral fin / gill opening 12, before dorsal-fin origin 16, and before anus 48.
Dorsal surface of body grayish, with numerous tiny black spots; some melanophores concentrated at tip of snout. Ventral side whitish. Dorsal and anal fins translucent; pectoral fin whitish.
Distribution.
Currently only known from the type locality, with sandy substrate.
Etymology.
The specific epithet taiwanensis refers to the location of the type locality, which recently only known in Taiwan; it is used as an adjective.
Remarks.
Compared to all 12 congeners, C. taiwanensis sp. nov. can be easily distinguished from 10 species, except C. odishaensis and C. orientalis, in having only a single row of mandibular teeth (Fig. 4). However, C. taiwanensis sp. nov. can be separated from these two species morphologically, with comparative details shown in Table 3. The new species differs from C. odishaensis in having a shorter pectoral fin, only 15.2 % of HL (compared to 21.3–25.0 % HL in C. odishaensis); fewer vertebrae, with 13 pre-dorsal, 53 pre-anal, and 150 total vertebrae (vs 10 pre-dorsal, 46–47 pre-anal, and 160–162 total vertebrae in C. odishaensis); and fewer rows of maxillary teeth (2–6 rows in C. taiwanensis sp. nov. vs 3–7 rows in C. odishaensis). Compared to C. orientalis, C. taiwanensis sp. nov. has a larger head at 9.7 % of TL (vs 5.5–6.2 % of TL in C. orientalis), significantly more vertebrae (150 vs 131–136 in C. orientalis), and more rows of maxillary teeth (2–6 rows in C. taiwanensis sp. nov. vs 2–3 rows in C. orientalis).
— No data available.
Molecular results.
Sixteen COI sequences from three taxa were analyzed, revealing nine unique haplotypes across 562 aligned base pairs, which included 196 variable sites and 151 parsimony-informative sites. The NJ tree analysis identified C. taiwanensis sp. nov. in a well-supported clade (bootstrap values 99 %) with all other Cirrhimuraena species included in NCBI (Fig. 5). The average pairwise K 2 P genetic distance between C. taiwanensis sp. nov. and its congeners is 0.124, aligning with the average genetic distance typically found among congeneric fish species, as reported by Ward et al. (2005). Within the Cirrhimuraena group, C. taiwanensis sp. nov. and most C. chinensis specimens are clearly separated (bootstrap value 99 %) from C. indica and two C. chinensis specimens collected in Indonesia (GU 674221.1 and GU 674224.1), which are suspected misidentifications of C. indica (Mohapatra et al. 2021). Cirrhimuraena taiwanensis sp. nov. also demonstrates a distinct separation from C. chinensis, with high bootstrap support of 82 % and forming a unique monophyletic group. The distinct morphological characteristics and NJ tree results further support the separation of C. taiwanensis sp. nov. as a distinct species.
description: Published as part of Lin, Yen-Ting, Lin, Yu-Hsiang & Han, Yu-San, 2025, Cirrhimuraena taiwanensis sp. nov., a new species of cirri-bearing eel (Anguilliformes, Ophichthidae) from Yilan, northeastern Taiwan, pp. 129-140 in ZooKeys 1224 on pages 129-140, DOI: 10.3897/zookeys.1224.141248