Friday, October 7, 2016

[Ichthyology • 2016] Cynoglossus nanhaiensis • A New Species of Tongue Sole (Pleuronectiformes: Cynoglossidae: Cynoglossus) from coastal waters of the South China Sea


Cynoglossus nanhaiensis 
Wang, Munroe & Kong, 2016

Abstract
A new tongue sole, Cynoglossus nanhaiensis, described from 21 specimens (101.0–133.7 mm SL) collected in coastal waters of the South China Sea, is distinguished from congeners by the following combination of characters: 3 ocular-side lateral lines; no blind-side lateral lines; 2 ocular-side nostrils; 8 caudal-fin rays; 49–51 total vertebrae; 64–73 scales in the midlateral line; 11–12 scales in diagonal series between midlateral and dorsal lateral lines; 99–108 dorsal-fin rays; 77–82 anal-fin rays; pores of lateral-line scales tubular, with conspicuously black tips posteriorly; and with light- to medium-brown ocular-side background coloration overlain by numerous, small, irregular, dark blotches forming a series of narrow, interrupted, longitudinal stripes, with many specimens also featuring two large, brown spots on their caudal region. Among congeners, C. nanhaiensis is most similar to C. maccullochi Norman, 1926, described from specimens taken off Queensland, Australia, but differs in its ocular-side pigmentation (conspicuous longitudinal series of irregular blotches and caudal spots absent in Cmaccullochi) and body depth. Features of C. nanhaiensis are also reminiscent of those reported for C. dollfusi (Chabanaud, 1931), a poorly-known nominal species from the Red Sea, and C. itinus (Snyder, 1909), a better-known species occurring in marine waters off Japan and Southeast Asia. Cynoglossus nanhaiensis differs from both species in having two (vs. one) ocular-side nostrils. Cynoglossus itinus also lacks the series of conspicuous, darkly-pigmented, interrupted, longitudinal stripes on the ocular side that are characteristic of C. nanhaiensisCynoglossus nanhaiensis is further distinguished from C. dollfusi in having only a single pelvic fin (vs. two in C. dollfusi). Cynoglossus nanhaiensis occurs in coastal waters of the South China Sea off southern China and Viet Nam.

Keywords: Flatfish, Tonguefish, Cynoglossid tongue sole


Fig. 1. Cynoglossus nanhaiensis, new species, holotype (fresh condition), SCSMBC007425, male, 127.6 mm SL.
A. Ocular side. B. Blind side. (Photograph: Z.-M. Wang). 



Distribution.— Based on fishery landings, this species occurs in coastal waters off Sanya and Lingshui, Hainan Province; Zhanjiang, Guangdong Province, China; two specimens were collected off Viet Nam, one in the Gulf of Tonkin (20°46′29.99″N, 107°04′40.8″E) and the other off Phan Thiet (10°55′20″N, 108°06′34″E).

Etymology.— The name, nanhaiensis, is derived from the Chinese word, Nanhai, meaning South China Sea, in reference to localities where most specimens were collected.


Zhong-Ming Wang, Thomas A. Munroe and Xiao-Yu Kong. 2016. A New Species of Tongue Sole (Pisces: Pleuronectiformes: Cynoglossidae: Cynoglossus) from coastal waters of the South China Sea. Proceedings of the Biological Society of Washington. 129(1); 129-143. DOI: 10.2988/0006-324X-129.Q2.129