Samariscus neocaledonia, Kawai, Toshio, Amaoka, Kunio & Séret, Bernard, 2011

Kawai, Toshio, Amaoka, Kunio & Séret, Bernard, 2011, Samariscus neocaledonia, a new righteye flounder (Teleostei: Pleuronectiformes: Samaridae) from New Caledonia, Zootaxa 3135, pp. 63-68 : 64-66

publication ID	https://doi.org/ 10.5281/zenodo.207959
DOI	https://doi.org/10.5281/zenodo.5692067
persistent identifier	https://treatment.plazi.org/id/03EE87F5-C13F-FFFA-E5BD-FF7DA6DA823D
treatment provided by	Plazi
scientific name	Samariscus neocaledonia
status	sp. nov.

Treatment

Samariscus neocaledonia View in CoL sp. nov.

Proposed common name: New Caledonian righteye flounder ( Figure 1 View FIGURE 1 )

Holotype: MNHN 2011-0231 (field tag BAT23), 50.0 mm SL, female, cruise BATHUS 3, Stn CP 804, 23º41.40’ S, 168º00.42’ E, 244–278 m depth, 27 Dec. 1993, beam trawl.

Paratype: HUMZ 212428 (field tag BAT 57.1), 34.6 mm SL, sex unknown, cruise BATHUS 4, Stn CP 936, 19º3.67’ S, 163º28.05’ E, 252–258 m, 8 Aug. 1994, beam trawl.

Diagnosis. A species of Samariscus with the following combination of character states: 78–81 dorsal fin rays, 62–65 anal fin rays, five pectoral fin rays, ca. 55–62 lateral line scales, and 10 abdominal and 31–32 caudal vertebrae.

Description. Counts and proportional measurements (% SL) of the holotype are listed first, followed by those of the paratype placed within parentheses.

Dorsal fin rays 81 (78); anal fin rays 65 (62); ocular-side pectoral fin rays 5 (5), pectoral fin absent on blind side; pelvic fin rays 5 (5) on both ocular side and blind-side fins; caudal fin rays 16 (16); lateral line scales 62 (ca. 55); abdominal vertebrae 10 (10), caudal vertebrae 31 (32); total vertebrae 41–42.

Head length 24.0 (23.1) % SL; body depth 39.8 (32.4); snout length 5.8 (5.8); upper eye diameter 6.6 (6.6); lower eye diameter 7.2 (7.2); orbital length 7.8 (8.7); interorbital width 0.6 (0.6); upper jaw length 7.0 (7.2) on ocular side, 6.0 (6.9) on blind side; lower jaw length 12.8 (12.7) on ocular side, 12.0 (11.6) on blind side; depth of caudal peduncle 13.2 (11.6); pectoral fin length 45.6 (30.1) on ocular side; pelvic fin length 14.8 (13.6) on ocular side, 9.4 (9.2) on blind side.

Body laterally compressed, elliptical, deepest at midpoint, depth 2.5 (3.1) in SL. Head small, length 4.2 (4.3) in SL. Snout short, length 4.1 (4.0) in HL, smaller than either eye diameter. Ocular-side anterior nostril a long tube situated in anterior interorbital space; ocular-side posterior nostril a short tube situated just dorsal to anterior nostril. Eyes dextral, separated by narrow, scaleless bony ridge. Upper eye diameter 3.6 (3.5) in HL, lower 3.3 (3.2) in HL. Mouth oblique, maxilla extending below anterior margin of lower eye, maxilla length on ocular side 3.4 (3.2), and on blind side 4.0 (3.3) in HL. Teeth small in bands on both jaws. Vomer and palatines toothless. Gill rakers on first arch rudimentary on both sides. Gill membranes united to each other, but not to body.

Scales ctenoid on both sides of body, on ocular side of head, and on blind side of dorso-posterior part of head; scales cycloid on remainder of blind-side head. Ocular-side lateral line almost straight; no lateral line on blind side.

Dorsal-fin origin anterior to upper eye on blind side of head. Anal-fin origin just posterior to anus. All dorsal and anal fin rays simple. Ocular-side pectoral fin relatively long, all rays simple, length 0.5 (0.8) in HL; no blindside pectoral fin. Pelvic fins small, subsymmetrical; first ray of blind-side fin opposite space between first and second ray of ocular-side fin; all rays simple, length of ocular side pelvic fin 1.6 (1.7), length of blind-side pelvic fin 2.6 (2.5) in HL. Caudal fin rounded, with 12 inner rays branched; other four rays simple, uppermost and lowermost two rays unsegmented. Anus on midventral line.

Color in alcohol. Ocular side of body yellowish brown with five indistinct dusky blotches along dorsal margin about from vertical thorough posterior head to end of dorsal fin base, four indistinct dusky blotches along anal margin about from vertical through second dorsal blotch to end of anal fin base, and with two indistinct blotches on lateral line; one obliquely posterior on second dorsal blotch and the other vertical through medial region between third and fourth dorsal blotches. Blind side of body uniformly milky white. Dorsal and anal fins dusky brown posteriorly. Pectoral fin on ocular side blackish. Caudal fin uniformly dusky brown.

Distribution. Known only from off New Caledonia, the western tropical Pacific Ocean, at 244–278 m depth.

Etymology. The specific name neocaledonia is derived from the collection locality, New Caledonia.

Remarks. Samariscus comprises 18 valid species: S. asanoi Ochiai & Amaoka, 1962 , S. corallinus Gilbert, 1905 , S. desoutterae Quéro, Hensley & Maugé, 1989 , S. filipectoralis Shen, 1982 , S. huysmani Weber, 1913 , S. inornatus ( Lloyd, 1909) , S. japonicus Kamohara, 1936 , S. latus Matsubara & Takamuki, 1951 , S. leopardus Voronina, 2009 , S. longimanus Norman, 1927 , S. luzonensis Fowler, 1934 , S. macrognathus Fowler, 1934 , S. maculatus ( Günther, 1880) , S. multiradiatus Kawai, Amaoka & Séret, 2008 , S. nielseni Quéro, Hensley & Maugé, 1989 , S. sunieri Weber & de Beaufort, 1929, S. triocellatus Woods, 1966 and S. xenicus Ochiai & Amaoka, 1962 .

The number of pectoral rays on the ocular side is a stable character useful for differentiating some of the species in Samariscus . Five pectoral rays in S. neocaledonia easily distinguishes this species from S. asanoi , S. corallinus , S. desoutterae , S. luzonensis , S. macrognathus , S. nielseni and S. xenicus , all of which have four pectoral fin rays ( Table 1 View TABLE 1 ). The relatively higher number of dorsal fin rays (78–81) and anal fin rays (62–65) in S. neocaledonia distinguishes this species from the remaining 11 congeners as follows: S. filipectoralis (71–77 and 53–58), S. huysmani (68–72 and 55–57), S. inornatus (61–70 and 48–53), S. japonicus (62–73 and 47–57), S. latus (67–76 and 52– 59), S. leopardus (72 and 59), S. longimanus (66–71 and 50–54), S. maculatus (73 and 57), S. multiradiatus (85–91 and 67–72), S. sunieri (70–76 and 54–61) and S. triocellatus (62–70 and 47–56) ( Table 1 View TABLE 1 ). In addition, the presence of 10 abdominal vertebrae in S. neocaledonia differs from the nine abdominal vertebrae found in S. filipectoralis , S. inornatus , S. latus , S. leopardus , S. longimanus , S. maculatus , S. multiradiatus , S. sunieri and S. triocellatus .

Samariscus neocaledonia has 31–32 caudal vertebrae versus 28–30 abdominal vertebrae in S. filipectoralis , 29 in S. huysmani , 28 in S. inornatus , 29 in S. japonicus , 29–30 in S. latus , 33 in S. leopardus , 29–30 in S. longimanus , 30 in S. maculatus and 34–35 in S. multiradiatus ( Table 1 View TABLE 1 ). Furthermore, lower number of lateral line scales (ca. 55–62) in S. neocaledonia is separated from higher number in the following four congeners, 70–75 in S. huysmani , 68–74 in S. sunieri and 69–76 in S. triocellatus ( Table 1 View TABLE 1 ).

Comparative materials. Samariscus asanoi : FAKU S297, 58.6 mm SL, holotype, Tongking Bay, Taiwan, 71 m depth, 30 July 1957. Samariscus filipectoralis : NTUM 5337, 83.1 mm SL (data from Shen, 1982), holotype, NTUM 5337, 78.4, 82.3 mm SL (data from Shen, 1982), 2 paratypes, Tungkong, Taiwan, 26 Oct. 1978.

S. corallinus View in CoL 75–77 63–65 4 98–ca. 100 9 36–37 Hawaii Data taken from Günther (1880), Gilbert (1905), Lloyd (1909), Weber (1913), Norman (1927, 1934), Weber & de Beaufort (1929), Fowler (1934), Kamohara (1936), Matsubara & Takamuki (1951), Ochiai & Amaoka (1962), Woods (1966), Shen (1982), Sakamoto (1984, 1988a, b, c), Quéro et al. (1989), Hensley (1993, 2001), Nakabo (2002), Senou et al. (2004), Mundy (2005), Hoese & Bray (2006), Randall (2007), Kawai et al. (2008) and Voronina (2009). A, anal fin rays; AV, abdominal vertebrae; CV, caudal vertebrae; D, dorsal fin rays; LLS, lateral line scales; P1, pectoral fin rays. Single asterisk indicates unable to count because of decalcification of holotype in the present study. Double asterisks indicate the data providing in the present study.