Synodus usitatus Cressey 1981

Benthic at ca. 100 m (Ref. 58302).

Synodus usitatus

MATERIAL EXAMINED.—Holotype: BPBM 15484, SL 123.2 mm, and 2 paratypes, BPBM 26544, SL 115.6, and USNM 225068, 96.2 mm, off Oahu, HAWAII, 27 Aug 1973, 55 fms, shrimp trawler Valiant Maid. Paratype: FAKU 5780, SL 95.5 mm, off Kumanonada, Mie Prefecture, JAPAN, 25 Mar 1938.

DIAGNOSIS AND COMPARISONS.—A species of Synodus with the following combination of characters: dorsal-fin rays (branched and unbranched) 12 anal-fin rays 8–9 (usually 9); pored lateral-line scales 58–60 (usually 58); transverse scale rows 3.5/5; vertebrae 57–59 (usually 57); combined dorsal and anal procurrent rays 26–29; anterior palatine teeth not longest and not in a discrete group; peritoneal spots 14–17; posterior pelvic process wide.

The pectoral fin of S. usitatus extends well beyond a line from the origin of the pelvic fin to the origin of the dorsal fin. All other known species of Indo-West Pacific Synodus except S. binotatus, S. macrocephalus, and S. oculeus are short of or just to this line. Synodus macrocephalus and S. oculeus have a narrow posterior pelvic process. The vertebral and peritoneal spot counts of S. binotatus are lower than those of S. usitatus (51–55, 0–3 vs. 57–59, 14–17 respectively).

DESCRIPTION (holotype plus range).—Dorsal-fin rays 12(11-12); anal-fin rays 8(8–9); pectoral-fin rays 13; pelvic-fin rays 8; procurrent rays 27 (26-29), dorsal 14(14-15), anal 13(12-14); lateral line continuous, 58 (58–59) pored scales; scale rows above lateral line from dorsal origin 3.5; scale rows below lateral line to anal origin 5; predorsal scales 15(15–16); rows of cheek scales 4; vertebrae 57(57–59); peritoneal spots 14(14–17).

Percentages of Standard Length: Mean (range): head length 29.4 (28.5–31.2); snout length 5.6(5.3–6.0); upper jaw length 18.6(17.3–20.1); diameter of bony orbit 6.3(5.9–6.6); least width of bony interorbital 2.3(2.1–2.5); snout to dorsal origin 43.0(41.6–44.3); snout to adipose origin 86.6(86.1–87.5); snout to anal origin 81.0(77.7–84.5); snout to pelvic insertion 35.9(34.8–37.5); snout to pectoral insertion 27.2(25.6–30.0); first-dorsal-ray length 9.3(8.6–10.0); longest-dorsal-ray length 15.3(13.3–17.3); pectoral-fin length 12.7(12.5–13.0); pelvic-fin length 25.7(24.3–27.0); dorsal-fin base 12.9(12.1–13.5); anal-fin base 9.0(7.8–9.9); based on 4 specimens 95.5 to 123.2 mm SL.

Body fusiform, head somewhat depressed, caudal region a little compressed. Large cycloid scales on body, extending onto cheeks and operculum, postoral portion of cheeks scaly. Snout not sharply pointed, broader than long; the anterior nostril on each side bearing a broad triangular dermal flap extending well beyond anterior margin of nares when depressed anteriorly. Interorbital space concave, occipital region bony. Palatine teeth in an elongate V-shaped pad, teeth pointing backwardly, those in front not largest and not in a discrete group. Lingual teeth well developed, those on free end of tongue largest and about 35 in number. Teeth caniniform, larger teeth with arrow-shaped tips. Pectoral fins reaching beyond a line from base of pelvic fins to origin of dorsal fin. Outer pelvic ray unbranched and short, fifth branched ray (sixth ray) longest. Posterior bony process of pelvic girdle broad. Peritoneum pale.

COLOR PATTERN.—Dorsum dark, a series of five saddle-like bands alternating dark and lighter with dark band at origin of dorsal fin, second near end of dorsal-fin base, third and fourth between dorsal fin and adipose fin, last near base of adipose fin; less conspicuous pigmented areas between each of the darker bands; dorsal fin with two to three faint bars; other fins unmarked except posterior edge of caudal fin of one specimen with pale band (from photo of fresh specimen by J. E. Randall).

DISTRIBUTION AND HABITAT.—This new species has been collected from Hawaii and Japan. The three Hawaiian specimens were collected at 55 fathoms, indicating a preference for deeper water than most other known Indo-West Pacific Synodus. Depth of capture data are unavailable for the Japan specimen. After this paper went to press, an additional specimen was sent to me from the Indian Ocean coast of Sumatra-Java by P. Whitehead (BMNH).

ETYMOLOGY.—The Latin usitatus (ordinary) alludes to a lack of any outstanding markings.

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*New record since Cressey and Cressey, 1979.

Synodus usitatus is a species of lizardfish that lives mainly in the indo-west pacific.