Trimmatom lanyuensis

(Figs. 1 – 2)

Description Body proportions from morphometric measurements for 4 type specimens are listed in Table 1. Head length 27.3 – 30.0 (average 28.2), predorsal length 35.0 – 36.4 (35.6), snout to 2 nd dorsal fin 54.0 – 56.1 (55.0), snout to anal fin origin 60.0 – 63.2 (61.5), prepelvic length 29.3 – 31.7 (30.8), caudal peduncle length 20.3 – 22.1 (21.4), caudal peduncle depth 13.6 – 15.2 (14.3), first dorsal fin 13.4 – 14.5 (13.8); second dorsal fin 22.3 – 26.1 (25.2), pectoral fin length 20.4 – 25.5 (22.8), and body depth of anal fin origin 18.1 – 19.6 (19.0) all in percentage of standard length. Snout length 15.6 – 17.1 (16.1), eye diameter 30.3 – 34.8 (33.3), postorbital length 46.3 – 48.4 (47.3), cheek depth 28.0 – 31.9 (30.0) and lower jaw length 36.8 – 39.6 (38.8) all in percentage of head length. Body elongated, head moderately compressed. Mouth oblique, maxilla extending posteriorly to vertical drawn through mid-pupil. Lower jaw protruding slightly beyond tip upper jaw. Anterior nasal opening with short, tapered tube reaching anteriorly to point above posterior margin of upper lip, posterior opening pore-like with low raised rim. Eyes large, positioned dorsolaterally. Narrow interorbital width with no trenches. Gill-opening large, extending anteroventrally to vertical line through posterior edge of orbit. Fins. — D 1 VI; D 2 10; A 10; P 21; V I / 5 + I / 5. Second spine of D 1 longest and elongate, reaching to fourth ray of D 2, even to posterior base of D 2 when depressed in male. D 1 membrane not connected to origin of D 2. D 2 usually unbranched. A origin located below second to third rays of D 2. P rays unbranched, not reaching to vertical drawn through anus. V well separated with no frenum; fourth ray unbranched and elongate (when undamaged reaching beyond the base last ray of anal-fin), fifth ray only about 6 – 10 % length of fourth ray. Scales. — LR 27 – 28 (modally 27); TR 8 – 9 (modally 8). Predorsal region entirely naked on mid-predorsal area. Nape, cheek or opercle all naked. Body with large ctenoid scales. Head lateral-line system (Fig. 1) Head canals and pores. No canal pore on head. Sensory papillae. Sensory papillae or free neuromasts distributed as follows, with counts and ranges shown in parentheses: Row a long, extending from posterior to anterior of orbit; rows b and d present; row c longitudinally; single cp papillae; row f paired. Coloration while fresh. (Fig. 2) Head and body with greyish brown background bearing bloody red marks. Lateral body with pale gray 5 vertical bars, anterior 4 longer extension to ventral side, the last one shorter passing less than only half way of lateral lateral side against the bright red body. Head generally with entirely gray in cheek. Opercle with two red vertical lines. The two lines interrupted to dorsal two cross red bars. Rear of interorbital region of a red band. First dorsal fin translucent with red rays and a basal longitudinal line. Second dorsal fin follow the pattern. Caudal fin pinkish red, with basal region bloody red. Pectoral fin bloody red with basal central red mark. Pelvic fin translucent and red rays. Anal fin pinkish red. Coloration after preservative The preserved specimens all faded into very light creamy yellow, all fins translucent and unmarked.

Diagnosis The new species. T. lanyuensis can be well distinguished from other congeneric species by the unique combination of following features: (1) fin rays: second dorsal fin rays 10, anal fin rays 10, pectoral fin rays 21; (2) squamation: longitudinal scale rows 27 – 28 (modally 27), predorsal naked; and (3) specific coloration: head and body with greyish brown background bearing bloody red marks. Lateral body with pale gray 5 vertical bars, anterior 4 longer extension to ventral side, the last one shorter passing less than only half way of lateral side against the red body. Head generally with entirely gray in cheek. Opercle with two red vertical lines. The two red lines interrupted to dorsal two cross red bars. Caudal fin pinkish red, with basal region bloody red. Pectoral fin bloody red with basal central red mark.

Remarks The new species is rather similar to T. eviotops than any other congeneric species. However, T. lanyuensis can be well distinguished from T. eviotops by the following features: (1) D 1 with the rather elongation spinous ray filament of first dorsal fin rays vs. none of them seen; (2) specific coloration: head with interrupted vertical red bars vs. continuous dark vertical bars, lateral body after first dorsal fin origin with 5 major vertical gray marks vs. 4 dark marks. The new species, T. lanyuensis can grow larger body size into about 20 mm SL, the E. eviotops with body size usually less than 14 mm SL.

Distribution The fish species merely found from the coastal waters off Lanyu Island, it is highly possible to be exist around other nearby countries of West Pacific region.

Etymology The specific name, lanyuensis, is referred to the type locality “ Lanyu - Orchid Island ”, Taiwan.

Material examined Holotype NTOUP- 2003 - 07 - 205, 18.2 mm SL, Yeyu, Lanyu (Orchid Island), Taitung County, Taiwan, ROC, coll. I-S. Chen, July 18, 2003. Paratypes NTOUP- 2003 - 07 - 206, 18.8 mm SL, collection data and date same as holotype. NTOUP- 2003 - 07 - 207, 16.7 mm SL, collection data and date same as holotype. NTOUP- 2003 - 07 - 208, 17.6 mm SL, collection data and date same as holotype.

(DZNJ 小Dzaem)