Synodus vityazi, Ho, Hsuan-Ching, Prokofiev, Artém M. & Shao, Kwang-Tsao, 2010

Ho, Hsuan-Ching, Prokofiev, Artém M. & Shao, Kwang-Tsao, 2010, Synodus cresseyi Prokofiev, 2008, an unnecessary replacement for S. macrocephalus Cressey, 1981, and a description of a new species from the Western Indian Ocean (Teleostei: Synodontidae), Zootaxa 2419, pp. 63-68 : 64-67

Synodus vityazi new species

( Figs. 2–3 , Table. 1)

Synodus cresseyi Prokofiev, 2008: 424 , figs. 1, 2a–2d (in part, 2 specimens, 104 and 131 mm SL).

Holotype. USNM 307924 (99.0 mm), R/V Vityaz II, cr. 17, st. 2829, bottom shrimp trawl, 12°04’–12˚10’ N 53°14’ –53˚09’E, northeast of Madagascar, W. Indian Ocean, 36–40 m, 15 Jan. 1989.

Paratypes. USNM 396992 (ex. USNM 307924, 6: 64.4–89.1 mm), same locality and date as for the holotype. IORAS 2617 (2: 104.0–131.0 mm), same locality and date as for the holotype.

Diagnosis. Dorsal rays 12 or 13; anal rays 9 or 10; pectoral rays 12 or 13; lateral line scales 56–58; scales between lateral line and base of dorsal fin 3.5; median predorsal scales 16 or 17; vertebrae 56 or 57; peritoneal spots 8; anterior palatine teeth not longer than posterior teeth; preopercle scaled posterior to corner of mouth; membranous posterior flap of anterior nostril slender, with a pointed tip, reaching to above posterior nostril when laid back; pectoral fins reaching a line connecting dorsal and pelvic fin origins, the fin length 2.3–2.6 in head length; pelvic processes wedge-shaped, broad at base; color in alcohol without any marking, deep brown on dorsal surface restricted to central two-third of head and body longitudinally, about two scale rows above the lateral line, lateral and ventral surface uniformly silvery white without any blotch; colorless in all fins, except for inner edge of caudal fin fork is black.

Description. Dorsal fin rays usually 12 (rarely 13), branched except first two, the last branched to base, the first ray about two-thirds of second ray in length; anal rays 9 or 10, unbranched except the last, branched to base; pectoral fin rays 12 or 13, the upper two and lowermost unbranched; pelvic fin rays 8, the rays with a slender posterior branch, except first and last, the first ray about one-third of the longest ray in length; principal caudal fin rays 19, the upper and lower unbranched; lateral line scales 56–58, not including three tubal scales curving ventrally on caudal fin base; scale rows between lateral line and dorsal fin 3.5; scale rows below lateral line to origin of anal fin 4; median predorsal scales 16–18 (uaually 16); circumpeduncular scales 17; gill rakers on ceratobranchial 32 or 33, 10 or 11 on upper limb and 21 or 22 on lower limb; vertebrae 56 or 57; peritoneal spots 8 (3 specimens examined).

Body slender, body width 7.2–7.8 in SL; head length (HL) 3.2–3.6 in SL; snout length 4.1–4.4 in HL; orbital diameter 3.5–4.2 in HL; interorbital space narrow, slightly concave when viewed anteriorly, the least bony width 13.1–15.4 in HL; caudal peduncle depth 5.4–7.2 in HL; caudal peduncle length 2.7–3.1 in HL. Mouth terminal and slightly oblique, forming an angle of about 15° to horizontal axis of body; mouth very large, extending more posterior to eye than anterior, the upper jaw length 1.6–1.8 in HL; teeth in jaws needlelike, the largest arrow-tipped, about equal in length to pupil diameter, and angling medially and anteriorly, except for a few teeth at front of jaws; teeth of upper jaw in 3 close-set rows, those of outer row fixed and rather apart, and largely covered by lip, medium and inner rows inwardly depressible, outer row about twice length of inner and medium teeth; teeth in lower jaw in 4 close-set rows, progressively smaller laterally, except for 2-3 enlarged anterior teeth, outermost row fixed, rather apart and hidden by lip, the other rows inwardly depressible; palatine teeth in 2 to 4 rows, progressively longer medially, angling medially and posteriorly; no vomerine teeth; anterior palatine teeth not enlarged, about equal to posterior teeth; about 35 posteriorly depressible teeth in 4 irregular rows on anterior part of tongue, followed by a relatively narrow tooth band bearing 4 irregular rows of smaller teeth.

Anterior nostril on a line from upper edge of orbit to tip of snout, half way to base of upper lip; membranous posterior flap of anterior nostril a slender flap, the pointed tip reaching to or beyond posterior margin of posterior nostril when laid back; posterior nostril nearly round, with only a slight rim at front, directly behind anterior nostril, the internarial distance about equal to posterior nostril diameter.

Predorsal scales extending forward to about half of orbital diameter behind eye vertically; posterior cheek fully scaled, with 5 slightly oblique latitude rows, progressively smaller posteriorly; a row of 5 scales on anterior part of opercle, each crossed by a sensory canal with 2 or 3 pores, the first in preopercular canal; remaining scales on opercle large and embedded except a few large scales at dorsal; no scales on dorsal, anal and paired fins; a broad central zone of scales basally on caudal fin, ending in a pair of very large pointed scales, 1 or 2 in each lobe, nearly reaching margin of fork of fin; a triangular scaly process at base of pelvic fin.

Predorsal length equal to distance from dorsal fin origin to rear base of adipose fin, 2.1–2.4 in SL; dorsal fin base 2.0– 2.3 in HL; second dorsal ray longest, 1.7–1.9 in HL; anal fin base 2.7–3.3 in HL; third anal ray longest, 3.0– 3.9 in HL; caudal fin forked, the lobes pointed, the longest rays 1.6–1.8 in HL; caudal concavity 3.4–4.7 in HL; pectoral fins just reaching a line connecting origins of dorsal and pelvic fins, the fin rounded when spread, 2.3–2.6 in HL; sixth pelvic ray longest, 1.0– 1.2 in HL.

IORAS USNM USNM 396922

2617 307924

Paratype Holotype Paratype

SL (mm) 131.0 104.2 99.0 89.1 82.7 77.7 77.5 75.4 64.4 Morphometrics

Proportion as % SL Ave. SD Body width 15.3 14.4 13.6 13.4 13.2 13.8 13.8 12.9 13.8 13.8 0.7 Head length 26.7 28.9 29.1 29.3 30.8 29.0 27.9 28.6 29.5 28.9 1.1 Caudal peduncle depth 4.2 4.8 4.0 5.1 5.1 4.9 4.6 5.3 4.8 4.8 0.4 Caudal peduncle length 13.0 13.5 9.9 10.5 11.5 9.4 9.8 11.0 9.6 10.9 1.5 Pre–dorsal fin length 42.0 43.3 43.5 45.1 47.0 42.5 42.1 43.6 44.9 43.8 1.6 Pre–anal fin length 81.7 76.9 77.7 78.1 79.9 78.2 76.8 77.9 77.3 78.3 1.6 Pre–adipose fin length 81.7 80.8 81.9 82.9 83.3 81.2 81.8 79.8 81.1 81.6 1.1 Pre–pelvic fin length 35.9 37.5 36.4 36.6 37.8 36.6 35.2 36.6 36.2 36.5 0.8 Dorsal fin base 13.0 13.5 14.3 12.8 14.6 14.0 13.5 12.7 12.9 13.5 0.7 Longest dorsal ray 14.5 15.9 16.4 16.0 17.5 15.1 16.3 17.0 16.5 16.1 0.9 Anal fin base 9.9 10.6 10.4 9.2 9.9 9.7 10.3 9.7 9.0 9.9 0.5 Longest anal ray 9.2 6.7 8.7 8.5 9.9 7.3 9.4 8.1 9.0 8.5 1.0 Caudal fin length 16.0 17.3 17.5 16.7 19.0 16.9 17.8 16.8 18.3 17.4 0.9 Caudal fork 6.1 8.2 7.4 6.3 7.0 6.4 7.9 8.4 7.3 7.2 0.8 Pectoral fin length 11.5 11.1 12.8 12.1 13.3 11.7 12.3 12.7 11.5 12.1 0.7 Pelvic fin length 25.2 25.0 23.5 26.3 27.0 25.7 27.0 26.0 26.2 25.8 1.1 Proportion as % HL

Snout length 25.7 23.3 23.6 22.6 22.7 23.1 22.7 22.7 24.2 23.4 1.0 Orbit diameter 18.6 20.0 24.0 23.8 23.9 25.3 27.8 28.2 24.7 24.0 3.2 Interorbital width 10.7 10.0 7.6 6.9 7.1 6.7 6.5 5.6 6.8 7.5 1.7 Upper jaw length 65.7 60.0 55.6 62.1 60.4 58.2 59.7 57.4 57.4 59.6 3.0 Meristics

Vertebrae 56 56 56 57 56 57 57 57 57 Pored lateral line scales 57 56 56 57 56 57 57 58 57 Predorsal scales 18 16 17 16 16 16 16 16 16 Dorsal fin rays 13 13 12 12 12 12 12 12 12 Anal fin rays 10 10 9 9 9 9 9 9 10 Pectoral fin rays 13 13 12 12 12 12 13 12 12 Caudal fin rays 19 19 19 19 19 19 19 19 19 Transverse scale row 3.5/5 3.5/5 3.5/5 3.5/5 3.5/5 3.5/5 3.5/5 3.5/5 3.5/5 Peritoneal spots 8 – 8 – 8 – – – –

Pelvic processes long, broad at base and pointed at apex, wedge–shaped.

Color in alcohol ( Fig. 2–3 ). Color in alcohol without any marking, deep brown on dorsal surface restricted to central two-thirds of head and body, about two scale rows above each side of the lateral line, lateral and ventral surface uniformly silvery-white, without any blotch; colorless in all fins, except for inner edge of caudal fin fork, black.

Etymology. The species is named for the research vessel Vityaz II, in recognition of its great contribution to deep-sea fish research and for collecting the type series described in present study.

Figures

FIGURE 2. Holotype of Synodus vityazi sp. nov., USNM 307924, 99.0 mm SL. A. Dorsal view. B. Lateral view.

FIGURE 3. Paratypes of Synodus vityazi sp. nov., USNM 396992, 4 of 6, 77.5 - 89.1 mm SL.