Pseudogramma xanthum Randall, Baldwin &amp; Williams, 2002, nomen novum
Creators: name: Randall, John E.
name: Baldwin, Carole C.
name: Williams, Jeffrey T.
Publisher: name: Zenodo
Year: 2002
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Serranidae
Pseudogramma
Pseudogramma xanthum

description: Pseudogramma xanthum, nomen novum (Figure 1, Table 1) Pseudogramma australis australis Randall and Baldwin, 1997 (type locality Temoe Atoll). Holotype: BPBM 13531, 39.1 mm, Tuamotu Archipelago, Gambier Group, Temoe Atoll (23°20’S, 134°30’W), N side of seaward reef, small cave, 41 m, rotenone, J.E. Randall and D.B. Cannoy, 16 December 1970. Additional material examined: BMNH 1996.6.27.1, 41.0 mm, Pitcairn Island, coral rubble and stone bottom, 99-102 m, station 6, dredge haul 17, crew of “Pele”, 20 October 1967; BPBM 37393, 4:22.4-35.0 mm, same data as holotype; BPBM 16893, 33.1 mm, Pitcairn Island, N side off Gannet Ridge, coral reef, 40-44.5 m, rotenone, J.E. Randall, D.B. Cannoy, J.R. Haywood, R.R. Costello, J.D. Bryant, and S.R. Christian, 6 January 1971; BPBM 13974, 2: 22.5-26.0 mm, Cook Islands, Rarotonga, off oil tanker buoy near harbor entrance, 23-30.5 m, rotenone, J.E. Randall and D.B. Cannoy, 11 March 1971; USNM 327795, 3: 26-27 mm, Tonga, Ha’apai Group, Ofolanga Island, SW side (19°36’15”S, 174°28’15”W), deep reef slope with sand channel at base and steep dropoff at end, 21-32 m, rotenone, J.T. Williams, B.B Collette, G.D. Johnson, D.G. Smith, C.C. Baldwin, and E.A. Powers, 12 November 1993. Diagnosis: Dorsal rays VII, 19-21; anal rays III, 16-18 (usually 17); pectoral rays 14- 15 (usually 15); one incomplete lateral line, pored scales 28-32; longitudinal scale series 50-52; gill rakers 6 + 10 or 11; a slender triangular dermal flap dorsally on eye of adults; tubular anterior nostril reaching about half way to posterior nostril when laid back; head length 40.3-43.1% SL; snout length 7.5-7.9% SL; orbit diameter 9.0-10.2% SL; upper-jaw length 19.3-21.1% SL; predorsal length 38.2-40.3% SL; head and body yellow in life with rows of large white blotches, a pale-edged brown spot on opercle; dark red dots on head, many in rows, and scattered dark red dots on body; largest specimen, 39.1mm SL. Description: Dorsal rays VII, 20 (19-21); anal rays III, 17 (16-18); pectoral rays 15 (14-15), all rays branched in adults; pelvic rays I, 5; principal caudal rays 17; upper procurrent caudal rays 4; lower procurrent caudal rays 3; one incomplete lateral line, the pored scales 30 (28-32); longitudinal scale series 50 (about 50-52); scale rows directly above lateral line to origin of dorsal fin about 6; scale rows directly below lateral line to origin of anal fin about 17 (rows partly overlapping and difficult to count); gill rakers 6 + 11 (6 + 11 or 12); pseudobranchial filaments 10 (7-9); branchiostegal rays 7; vertebrae 10+16. Body depth 3.55 (3.6-4.25) in SL; body width 1.8 (1.6-2.0) in body depth; head length 2.45 (2.3-2.5) in SL; snout length 5.4 (5.3-5.6) in head length; orbit diameter 4.3 (4.1-4.6) in head length; interorbital narrow and nearly flat, the least fleshy width 11.5 (10.9-12.5) in head length; caudal-peduncle depth 3.2 (3.25-3.5) in head length; caudal-peduncle length 5.35 (5.25-5.45) in head length. Mouth terminal or with lower jaw slightly projecting, oblique, forming an angle of about 35° to horizontal axis of head, and large, the maxilla extending well beyond a vertical at rear edge of eye, the upper-jaw length 2.1 (1.95-2.15) in head length; a small, triangular, ventrally-projecting, bony process posteriorly on maxilla; a small fixed incurved canine tooth (sometimes a close-set pair) anteriorly on each side of upper jaw; an inner band of small, conical, inwardly depressible teeth at front of upper jaw in about 6 irregular rows, progressively longer medially, the innermost symphyseal teeth longer than canines, though more slender; band of teeth narrowing to 1 or 2 irregular rows posteriorly in jaw; dentition of lower jaw similar to upper but without the fixed canines, with only 4-5 rows of teeth anteriorly, the largest teeth of inner row continuing along side of jaw; vomer with a V-shaped patch of small conical teeth in 3 irregular rows; palatines with a long band of small conical teeth in 1-2 irregular rows. Tongue long and slender, reaching slightly anterior to vomerine teeth. Opercle with 3 flat spines covered by scales; posterior margin of preopercle with a strong spine projecting obliquely downward, its base at level of lower edge of eye. A slender triangular flap longer than pupil extending upward from dorsal surface of eye (small and more triangular on smallest paratypes). Tubular anterior nostril near base of upper lip at level of lower edge of pupil, reaching about half distance to posterior nostril when laid back; posterior nostril at edge of orbit, slightly dorsal to anterior nostril, and vertically oval with a slight rim. A pair of large pores in midinterorbital space with a median pore behind; 12 other large pores encircling orbit; 4 large pores on mandible continuing as 7 pores along edge of preopercle. Scales on body small and adherent, their surface with prominent horizontal ridges, those posterior to about tenth lateral-line scale rhomboid and ctenoid, the middle cteni longest; small cycloid scales on nape extending into posterior interorbital space; small cycloid scales on opercle and cheek; rest of head naked; small scales on about basal half of fins except pelvics where only basally; no scales in axil of pectoral fins; lateral line paralleling dorsal contour of body, ending below middle of base of soft portion of dorsal fin. Origin of dorsal fin above fifth lateral-line scale, the predorsal length 2.6 (2.5-2.6) in SL; first dorsal spine 5.6 (5.4-5.75) in head length; fifth or sixth dorsal spines longest, 4.0 (3.8-3.95) in head length; last dorsal spine 4.95 (4.5-4.85) in head length; longest dorsal soft ray 2.85 (2.6-2.75) in head length; origin of anal fin below base of third dorsal soft ray, the preanal length 1.5 (1.5-1.55) in SL; first anal spine 6.9 (7.l-8.55) in head length; second anal spine clearly largest, 4.7 (4.2-4.8) in head length; longest anal soft ray 2.8 (2.55-2.8) in head length; caudal fin rounded and small, 1.8 (1.6-1.5) in head length; middle pectoral rays longest, 1.3 (1.2-1.3)in head length; origin of pelvic fins anterior to base of pectorals, the prepelvic distance 2.95 (2.8-3.1) in SL; second and third pelvic soft rays longest, 2.65 (2.6-2.7) in head. Color of holotype entirely pale yellowish. Color when fresh light yellow, shading to white on abdomen, chest, and ventral half of head, with two rows of indistinct pale blotches larger than pupil, one positioned midlaterally and one on lower side, scattered dark red dots (red with dark brown centers) on body; opercle with irregular pale-edged brown blotch rimmed with dark red dots; numerous dark red dots on dorsal half of head, those on lower half of head more widely separated but most arranged in lines, four of which pass ventrally from anterior half of eye, the first three crossing lips onto chin; fins light yellowish, the dorsal with a few dark red dots on base. A color photo (by JTW) of a specimen from Tonga is essentially the same as that of the holotype (Fig. 1) from the Tuamotu Archipelago. Etymology: The specific epithet is derived from the Greek adjective xanthos, meaning yellow, in reference to the ground color of the body. Remarks: The species redescribed above was first treated as a subspecies of Pseudogramma australis, but was mistakenly named P. a. australis. The name P. australis has been shown above to be occupied by the Easter Island species and does not apply to the western species. The subspecies P. a. pasquensis is a junior synonym of P. australis. Thus there is no name available for the western species of the P. australis group, and we provide P. xanthum as the new replacement name for P. a. australis. Pseudogramma australis and P. xanthum have the same basic color pattern, but differ in ground color, red for the former and yellow for the latter. However, we have records of the life color of P. xanthum from only Temoe and Tonga. In addition to the meristic differences between P. xanthum and P. australis discussed for the two subspecies of australis in Randall &amp; Baldwin (1997: tables 1-3), and the smaller size of xanthum, we note the following differences in proportional measurements: P. xanthum has a larger head (40.7- 43.1% SL, compared to 37.0-39.4% for P. australis); longer snout (7.5-7.9% SL, compared to 6.7-7.4% for P. australis); longer upper jaw (19.3-21.1% SL, compared to 18.5- 19.7%); and longer predorsal length (38.2-40.3% SL, compared to 36.4-38.2%). The eye size of P. xanthum is larger (9.0-10.2% SL, compared to 8.4-9.1%), but this is probably due to the smaller size of the specimens of P. xanthum. From the tables, P. xanthum seems to have a shorter caudal fin, but only three specimens could be measured due to the poor condition of most specimens.
description: Published as part of <i>John E. Randall, Carole C. Baldwin &amp; Jeffrey T. Williams, 2002, Pseudogramma xanthum, a new replacement name for a serranid fish from the subtropical South Pacific Ocean with description of the species., pp. 1-8 in Zootaxa 40</i> on pages 3-7