Synodus randalli Cressey 1981

Synodus randalli

MATERIAL EXAMINED.—Holotype: BPBM 24807, SL 113 mm, off Port Sudan, RED SEA, 80 fms, hook and line, 8 Jan 1980, coll. A. Medina and J. Randall.

DIAGNOSIS AND COMPARISONS.—A species of Synodus with the following combination of characters: dorsal-fin rays (branched and unbranched) 13; anal-fin rays 8; pored lateral-line scales 55; transverse scale rows 3.5/4; vertebrae 54; combined dorsal and anal procurrent rays 29; anterior palatine teeth longest and in a discrete group; peritoneal spots 14; posterior pelvic process wide.

The high peritoneal spot count separates S. randalli from all known Indo-West Pacific Synodus except S. usitatus.. Of the four known species with more than 12 peritoneal spots, S. usitatus and S. rubromarmoratus have short anterior palatine teeth; those of S. randalli are long. Syndous jaculum has 5.5 scales above the lateral line; S. randalli has 3.5. Synodus hoshinonis has a short rounded flap on the anterior nares and a conspicuous black pigmented area on the operculum; S. randalli has a long, triangular flap and no conspicuous black pigmented area on the operculum.

DESCRIPTION—Dorsal-fin rays 13; anal-fin rays 8; pectoral-fin rays 12; pelvic-fin rays 8; procurrent rays 29, 16 dorsal, 13 anal; lateral line continuous, 55 pored scales; scale rows above lateral line from dorsal origin 3.5; scale rows below lateral line to anal origin 4; predorsal scales 13; rows of cheek scales 5–7; vertebrae 54; peritoneal spots 14.

Percentages of Standard Length: Head length 28.3; snout length 7.2; upper jaw length 17.9; diameter of bony orbit 6.8; least width of bony interorbital 3.5; snout to dorsal origin 44.0; snout to adipose origin 83.1; snout to anal origin 82.2; snout to pelvic insertion 38.6; snout to pectoral insertion 35.5; first-dorsal-ray length broken; longest-dorsal-ray length 15.7; pectoral-fin length 13.2; pelvic fin length 24.1; dorsal-fin base 16.0; anal-fin base 8.4; based on 1 specimen 113 mm SL.

Body fusiform, head somewhat depressed, caudal region a little compressed. Large cycloid scales on body, cheeks, and operculum, postoral portion of cheeks scaly. Snout sharply pointed, broader than long; the anterior nostril on each side bearing a long; the anterior nostril on each side bearing a long triangular dermal flap extending well beyond the anterior edge of the nares when depressed anteriorly. Interorbital space concave, occipital region bony. Palatine teeth in an elongate V-shaped pad, teeth pointing backwardly, those in front largest and in a discrete group. Lingual teeth well developed, those on free end of tongue largest and about 40 in number. Teeth caniniform, larger teeth with arrow-shaped tips. Pectoral fin reaching beyond a line from base of pelvic fin to origin of dorsal fin. Outer pelvic ray unbranched and short, fifth branched ray (sixth ray) longest. Posterior bony process of pelvic girdle wide. Peritoneum pale.

COLOR PATTERN.—Preserved specimens pale. Color photo (by J. Randall) shows a series of reddish brown saddle-like bands similar to those found in S. variegatus. Dorsal-fin with 3 to 4 similarly colored bars. A conspicuous spot on the adipose fin.

DISTRIBUTION AND HABITAT.—This species is known only from a single specimen from the Red Sea caputured at a depth of 80 fathoms.

ETYMOLOGY.—This species is named for Dr. J. E. Randall, who collected the specimen and has been an enthusiastic supporter of this revision.

Synodus rubromarmoratus Russell and Cressey, 1979

Synodus rubromarmoratus Russell and Cressey, 1979:172 [Great Barrier Reef].

MATERIAL EXAMINED.—Holotype: AMS I.19450027, Lizard Island, AUSTRALIA. Paratypes (12): AMSI.19450–024 (10), USNM 218792 (2), Lizard Island. AUSTRALIA. TAIWAN (4): USNM 217615. PHILIPPINES (2): USNM 136282.

DIAGNOSIS AND COMPARISONS.—A species of Synodus with the following combination of characters: dorsal-fin rays (branched and unbranched) 10–12 (usually 11); anal-fin rays 9; pored lateral-line scales 54–55 (usually 54); transverse scale rows 3.5/5–6; vertebrae 52–55 (usually 53); combined dorsal and anal procurrent rays 24–29; anterior palatine teeth not logest and not in a discrete group; peritoneal spots 12–13; posterior pelvic process wide.

The pectoral fin of S. rubromarmoratus does not reach to a line from the origin of the pelvic fin to the origin of the dorsal fin. This separates it from all known Indo-West Pacific species except S. fuscus, S. indicus, S. kaianus, and S. sageneus. The anterior palatine teeth of S. fuscus are long and in a discrete group, and the peritoneal spot count of S. fuscus is lower (9–10). The dermal flap on the anterior nares of S. indicus is long, trianglular, and pointed (S. rubromarmoratus, broad and blunt). The peritoneum of S.kaianus is black (S. rubromarmoratus, pale). The anal-fin base of S. sageneus is longer than the dorsal-fin base.

This species superficially resembles S. macrops, S. macrocephalus, and S. oculeus and might be easily confused with them, but the narrow posterior pelvic processes of those three species separate them from S. rubromarmoratus.

DESCRIPTION.—Dorsal-fin rays 10–12; anal-fin rays 9; pectoral-fin rays 11–12; pelvic-fin rays 8; procurrent rays 24–29; dorsal 13–16, anal 11–14; lateral line continuous, 54–55 pored scales; scale rows above lateral line from dorsal origin 3.5; scale rows below lateral line to anal origin 5–6; predorsal scales 14–16; rows of cheek scales 5; vertebrae 52–55; peritoneal spots 12–13.

Percentages of Standard Length: Mean (range): head length 26.9(23.8–29.2); snout length 5.7(4.8–6.4); upper jaw length 14.9(12.9–16.7); diameter of bony orbit 6.4(5.2–7.4); least width of bony interorbital 2.2(1.7–2.5); snout to dorsal origin 43.0(40.7–45.0); snout to adipose origin 84.4(81.7–88.1); snout to anal origin 77.7(75.4–80.4); snout to pelvic insertion 35.4(31.3–38.2); snout to pectoral insertion 25.8(23.5–27.6); first-dorsal-ray length 11.3(8.7–16.6); longest-dorsal-ray length 16.2(14.3–17.8); pectoral-fin length 12.0(10.9–13.0); pelvic-fin length 22.2(20.2–24.7); dorsal-fin base 12.1(10.2–13.5); anal-fin base 8.8(6.9–9.6); based on 17 specimens 49.0 to 73.5 mm SL.

Body fusiform, head somewhat depressed, caudal region a little compressed. Large cycloid scales on body, cheeks, and operculum, postoral portion of cheeks scaly. Snout sharply pointed, broader than long; the anterior nostril on each side bearing a long leaflike flap on posterior margin extending well beyond anterior edge 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 small, those on free end of tongue largest and about 25 in number. Teeth caniniform. Pectoral fins not reaching 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.—Preserved specimens with 8 lateral patches of pigment similar in configuration to those of S. variegatus. In life, body mottled with red (see Russell and Cressey, 1979, for more complete life-color description).

DISTRIBUTION, HABITAT, AND VARIATION.—Known only from the western Pacific (southern tip of Taiwan, Philippines, Great Barrier Reef). Occurs in shallow (0–6 m Taiwan specimen) to moderately deep water (15 m Great Barrier Reef specimens).

The Taiwan specimens have only five rows of scales below the lateral line (others have six) and were from a generally rocky habitat with some nearby coral.

Synodus randalli is a species of lizardfish that lives mainly in the Western Indian Ocean and the Red Sea.