A new tongue sole of the genus Cynoglossus from the East China Sea and Yellow Sea (Pleuronectiformes: Cynoglossidae)

Abstract

Cynoglossus yokomaru sp. nov., previously known as Cynoglossus sp., called “Otafuku-genko” (the standard Japanese name), is described based on 15 specimens [64–226 mm in standard length (SL)] collected at depths of 73–157 m in the East China Sea and Yellow Sea. The new species belongs to the Cynoglossus kopsii complex as redefined in this paper and clearly differs from its congeners by the following combination of characters: two ocular-side lateral lines (dorsolateral and midlateral lines present, ventrolateral line absent); no blind-side lateral line; ctenoid scales present on both sides; two ocular-side nostrils; ocular-side posterior nostril immediately anterior to a point between eyes; head length (HL) shorter than its depth; posterior margin of upper jaw on ocular side not reaching below posterior margin of lower eye; body depth 25.8–30.2% SL; upper supraorbital length 35.5–47.3% HL; lower supraorbital length 48.8–64.3% HL; horizontal diameter of lower eye 10.1–17.4% HL; a long and continuous dorsolateral line with 61–70 scales; midlateral-line scales 4–5 + 65–68 = 69–73; scales above dorsolateral line 3–4; scales between dorsolateral line and midlateral line 10–12; cephalodorsal-line scales 8; dorsal-fin rays 115–119; anal-fin rays 90–94; caudal-fin rays 10 (rarely 8 or 9); and vertebrae 9 + 47–48 = 56–57.