Lycenchelys aurantiaca

description

Description. Counts and proportional measurements in Table 2. Body elongate, in cross section oval anteriorly, compressed laterally near tail; its width at anal-fin origin 3.7 – 7.7 (4.0) % SL. Head short, ovoid; dorsal profile of head gently sloping to dorsal-fin origin. Cheek more swollen in large specimens (including holotype) than in small specimens. Head of adults longer in males than in females. Snout short, 67.5 – 111.4 (106.0) % of eye diameter. Eye ovoid, moderately large. Interorbital space narrow, width 10.9 – 33.7 (26.7) % of eye diameter. Nostril tube short, not reaching upper lip when depressed. Mouth subterminal. Posterior edge of upper jaw about reaching vertical through 5 th suborbital pore in adult males (including holotype), reaching below posterior margin of eye in females and juveniles. Labial lobe of lower jaw weak. Teeth on jaws, vomer and palatine small and conical; upper jaw with 2 – 3 rows anteriorly and single row posteriorly; lower jaw with 2 – 4 irregular rows anteriorly and single row posteriorly; vomerine teeth irregularly arranged; palatine teeth in single row. Lower edge of gill opening slightly above lower end of pectoral-fin base. Opercular flap w

Taxonomic revision of the genus Lycenchelys (Osteichthyes: Zoarcidae) in Japanese waters

description

Size. The largest specimen examined during this study measured 141.3 mm SL (143.6 mm TL), exceeding the previously recorded maximum length of 135.8 mm SL (140 mm TL) (Shinohara & Matsuura, 1998; Hatooka, 2000, 2002, 2013; Amaoka et al., 2011).

Taxonomic revision of the genus Lycenchelys (Osteichthyes: Zoarcidae) in Japanese waters

diagnosis

Diagnosis. Vertebrae 19 – 20 + 66 – 70 = 85 – 89; head length 14.3 – 18.4 % SL; interorbital pore 1; occipital pores absent; postorbital pores 4; suborbital pores 5 + 1; preoperculomandibular pores 7 (rarely 8); vomerine teeth 4 – 10; palatine teeth 8 – 25, arranged in single row; opercular flap well-developed; pelvic-fin base positioned anterior to lower edge of gill opening; lateral line incomplete and positioned ventrally; scales absent on pectoral fin and its base; body uniformly reddish orange when fresh.

Taxonomic revision of the genus Lycenchelys (Osteichthyes: Zoarcidae) in Japanese waters

discussion

Remarks. Lycenchelys aurantiaca is similar to L. squamosa in having less than 100 total vertebrae, 1 interorbital pore, no occipital pores, 4 postorbital pores and no distinct spots or blotches on the body (vs. without this combination of characters in other species of Lycenchelys) (e. g., Toyoshima, 1983, 1985; Shinohara & Matsuura, 1998; Hatooka, 2000, 2002, 2013; Shinohara & Anderson, 2007; this study). Lycenchelys aurantiaca can be easily separated from L. squamosa in having lower numbers of dorsal-fin rays (82 – 86 vs. 88 – 91), anal-fin rays (68 – 72 vs. 73 – 77) and pectoral-fin rays (13 – 16 vs. 17 – 19), and total vertebrae (85 – 89 vs. 91 – 95), respectively. In addition, L. aurantiaca is distinguished from L. squamosa in having a uniformly reddish orange body when fresh and lacking scales on the pectoral fin and its base (vs. body uniformly dark brown when fresh and scales present on the pectoral fin and its base in L. squamosa) (Toyoshima, 1983, 1985; Shinohara & Matsuura, 1998; this study). Lycenchelys aurantiaca has previously been recorded only from off Tohoku District, the northwestern Pacific (Shinohara & Matsuura, 1998; Imamura, 1998; Hatooka, 2000, 2002, 2013; An

Taxonomic revision of the genus Lycenchelys (Osteichthyes: Zoarcidae) in Japanese waters