Spectrunculus stenostio, Uiblein & Møller & Nielsen, 2023

Uiblein, Franz, Møller, Peter R. & Nielsen, Jørgen G., 2023, The Systematics of the Ophidiid Genus Spectrunculus (Teleostei, Ophidiiformes) Revisited with Description of a New Species and Resurrection of S. radcliffei, Ichthyology & Herpetology 111 (3), pp. 467-485 : 468-470

Spectrunculus stenostio , new species

urn:lsid:zoobank.org:act:006F3321-FAA4-47DD-8415-3C40FB61AEE2

Figures 1–4 , Tables 1–3

Spectrunculus grandis (G unther €, 1877); Duhamel et al., 2005; in part: Nielsen and Hureau, 1980; Uiblein et al., 2008.

Holotype.— ZMUB 18493 (ZMUB-MAR-ECO 20149), female, 825 mm SL (pale), N Atlantic, 42825.49 0 N, 29848.14 0 W to 42825.49 0 N, 29846.13 0 W, M/S LORAN, sta. 13, bottom longline, 2018–2429 m depth, 8 July 2004.

Paratypes.— All North Atlantic (n ¼ 22) : ZMUB 18477 (ZMUB-MAR-ECO 12291), male, 650 mm SL (pale), 42848.6 0 N, 29838.36 0 W to 42846.64 0 N, 29838.59 0 W , R / V G.O. SARS, sta. 42-368, bottom trawl, 2063–2107 m depth, 8 July 2004 ; ZMUB 18478 (ZMUB-MAR-ECO 13347), female, 825 mm SL (pale), 42846.2 0 N, 29816.2 0 W , R / V G.O. SARS, sta. 46- 372, bottom trawl, 3005–3050 m depth, 11 July 2004 ; ZMUB 18479 (ZMUB-MAR-ECO 2617), male, 830 mm SL (pale), 4382.07 0 N, 28833.11 0 W to 4380.88 0 N, 28834 0 W , R / V G.O. SARS, sta. 50-373, bottom trawl, 2593–2607 m depth, 12 July 2004 ; ZMUB 18480 (ZMUB-MAR-ECO 13977), male, 670 mm SL, female, 840 mm SL (both pale), 42855.32 0 N, 2888.35 0 W to 42853.05 0 N, 2888.33 0 W , R / V G.O. SARS, sta. 52- 374, bottom trawl, 2973–2979 m depth, 13 July 2004 ; ZMUB 18481 (ZMUB-MAR-ECO 13821), male, 680 mm SL (pale), 5387.8 0 N, 34845.6 0 W , R / V G.O. SARS, sta. 68-384, bottom trawl, 2306–2374 m depth, 25 July 2004 ; ZMUB 18482 (ZMUB-MAR-ECO 16013), male, 725 mm SL , ZMUB 18483 (ZMUB-MAR-ECO 16027), male, 975 mm SL , ZMUB 18484 (ZMUB-MAR-ECO 16041), female, 858 mm SL , ZMUB 18485 (ZMUB-MAR-ECO 16055), female, 765 mm SL (all pale), 42834.91 0 N, 2882.64 0 W to 42833.91 0 N, 2885.84 0 W, M/S LORAN, sta. 1, bottom longline, 2925– 2827 m depth, 5 July 2004 ; ZMUB 18486 (ZMUB-MAR-ECO 17105), female, 950 mm SL , ZMUB 18487 (ZMUB-MAR-ECO 20065), female, 742 mm SL , ZMUB 18488 (ZMUB-MAR-ECO 20079), male, 625 mm SL , ZMUB 18489 (ZMUB-MAR-ECO 20093), female, 825 mm SL , ZMUB 18490 (ZMUB-MAR-ECO 20107), male, 685 mm SL , ZMUB 18492 (ZMUB-MAR-ECO 20135), female, 925 mm SL , ZMUB 18494 (ZMUB-MAR-ECO 20163), female, 885 mm SL (all pale) , ZMUB 18491 (ZMUB-MAR-ECO 20121), female, 895 mm SL (pale with several large brown rings on body), same station data as HT; ZMUC P 77793, 960 mm SL, ZMUC P77794 800 mm SL , ZMUC P77795 , male, 960 mm SL , ZMUC P 77796, 730 mm SL (all pale), 43839.3 0 N, 22837.8 0 W, R / V WALTHER HERWIG, sta. 82-352, beam trawl, 1900–2080 m depth, 8 June 1982 .

Non-type material.— S Indian Ocean E (n ¼ 4): MNHN 2003- 0598 , 754 mm SL (dark), MNHN 2003-0599 , 962 mm SL (light brown), Kerguelen, 50850.3 0 S, 69844.1 0 E, F/ V Ile Bourbon, longline, 1768 m depth, 11 October 2002 ; SAIAB 118942 , 2, 706 mm SL (dark) and 1001 mm SL (light brown), near Lena Tablemount, 53830 0 S, 48831.5 0 E, F/ V SHINSEI MARU, nr. 3, longline, 2112 m depth, 19 May 2010 .

SW Pacific (n ¼ 5): CSIRO H-5304.01, female, 1060 mm SL (light brown when fresh, pale after preservation), 38834 0 S, 149828 0 E to 38836 0 S, 149833 0 E, 1954–1979 m depth, 19 April 2000 ; CSIRO H-6036.02, female, 510 mm SL (light brown when fresh, pale after preservation), 3283 0 S, 159852 0 E to 3282 0 S, 159851 0 E, NORFANZ cruise, R / V TANGAROA , station 0308/071, 1920–1934 m depth, 24 May 2003 ; NMNZ P.031193, female, 610 mm SL (pale), 42855.59 0 S, 172839.21 0 E, R / V TANGAROA , sta. TAN 9406/ 226, 1694–1707 m depth, 22 June 1994 ; NMNZ P.033111, female, 1030 mm SL (pale), 37830 0 S, 176830 0 E; USNM 215295, 248 mm SL (pale), 42811 0 S, 175811 0 E, 2602–2619 m depth, 20 September 1966 .

Diagnosis.— Number of dorsal-fin rays 137–148, anal-fin rays 102–112, total vertebrae 80–88, pre-anal length 47– 55% in SL, pelvic- to anal-fin origin 34–44% in SL, orbit length 9.9–12 in % HL, otolith ostium width 15–21 in % sulcus length and 19–29 in % ostium length; maximum size to 110 cm SL.

Description.— The most important meristic and morphometric characters as well as the otolith characters are shown in Tables 1–3. Body elongate, laterally compressed, tapering towards tail. Pectoral-fin depth 5.7–7.9 times in SL, tail length 1.76–1.90 times in SL and preanal length 1.01–1.15 times in tail length. Head length 4.7–5.6 in SL and 2.23–2.75 in preanal length; head depth through eye 7.8–9.5 times in SL. Orbit circular, shorter than snout, 2.09–2.80 in snout length. Anterior gill arch with 8–10 long and 10–13 rudimentary rakers. Pseudobranchial filaments 0–2.

Origin of dorsal fin above vertebra 9–11, well in front of distal tip of pectoral fin. Pelvic fins with two rays each reaching about 1/3 from its base to anal-fin origin. Pectoral fins on lower half of body, rather short, 10–14 times in SL, and moderately wide at fin base, the width 19–21 times in SL.

Otolith ( Fig. 3A ) mostly elongate, length to height ratio 1.41–2.25, with pointed posterior tip. Anterior tip rounded. Dorsal surface concave. Sulcus long, 54–81% of otolith length with separated colliculi and located at the center of inner face. Ostium narrow, its width 15–21% of sulcus length and 19–29% of ostium length.

Coloration.— Freshly or recently caught specimens with pale creamy body and head, unpaired fins dark brown along distal margins or more entirely, as observed in the 19 type specimens collected by the MAR-ECO cruise, North Atlantic , in 2004. One of those specimens showed in addition several large brown rings on body. Of four specimens collected in the Southern Indian Ocean, the two smaller ones (706–754 mm SL) were dark brown and the two larger ones (962–1001 mm SL) light brown. In three of those specimens, the unpaired fins were dark brown .

Etymology.— The new species name is composed of the Greek word for narrow “stenós” and the otolith structure “ostium.” The ablative of the combined term is “stenostio ,” meaning “with a narrow ostium.”

Distribution.— This species is distributed in the North Atlantic and Southern Indian Ocean to the Southwest Pacific (1694 to 3050 m depth). There are no records from the South Atlantic.

Remarks.— Among the studied specimens that could be sexed were 9 males and 15 females. No sexual dimorphism could be found in any meristic and morphometric characters including otolith characters. A clear negative allometry in otolith length, but not in ostium and sulcus shape, was detected ( Fig. 4 ). Apart from a slight decrease in relative orbit length with size ( Fig. 4 ), no other allometric changes in body shape were encountered in Spectrunculus stenostio . A slight shift towards a lower number of total vertebrae was found in the Indo-Pacific population, while dorsal- and anal-fin ray number do not follow this trend ( Table 2). Small-sized specimens (, 200 mm SL) not known; the smallest specimen studied is 248 mm SL.

Figures

FIG. 1. (A–C) Spectrunculus stenostio: (A) HT, ZMUB 18493, 825 mm SL, N Atlantic (F. Uiblein); (B) SAIAB 11892, 706 mm SL, S Indian Ocean (F. Uiblein); (C) NMNZ P.033111, 1030 mm SL, SW Pacific (P. R. Møller). (D–F) S. crassus: (D) ZMUB 18355, 187 mm SL, N Atlantic (MAR-ECO cruise); (E) HT, MNHN 1886-0552, 284 mm SL, N Atlantic (J. Pfliger); (F) ZMUB 18463, 500 mm SL, N Atlantic (MAR-ECO cruise); (G–I) S. grandis: (G) HT, BMNH 1887, 675 mm SL (F. Uiblein); (H) NMNZ P.041204, 840 mm SL, SW Pacific (P. R. Møller); (I) CAS 25724, 1270 mm SL, NE Pacific (Moulin Studios, San Francisco, used with permission); (J–M) S. radcliffei: (J) HT (postlarva), FMNH 57123, 56 mm SL, NW Pacific (FMNH Zoological Collections, used with permission); (K) SAM 47240, 541 mm SL, S Atlantic (F. Uiblein); (L) ZMUC P2397445, 945 mm SL, NW Pacific (M. A. Krag); (M) ZMUC P2397724, 1020 mm SL, NW Pacific (M. A. Krag). Length of black or white scale bars is 5 cm.

FIG. 2. Distribution map showing the occurrence of studied specimens of the genus Spectrunculus. For areas with multiple occurrences, numbers are added to the respective symbols. Type localities are indicated by filled symbols.

FIG. 3. Images of otoliths of Spectrunculus. (A) S. stenostio, ZMUB 18480, 670 mm SL, N Atlantic (F. Uiblein); (B) S. crassus, ZMUB 18464, 575 mm SL, N Atlantic (F. Uiblein); (C–E) S. grandis: (C) HT, BMNH 1887, 675 mm SL, NW Pacific (CT scan, B. Clark); (D) CAS 25724, 1270 mm SL, NE Pacific (F. Uiblein); (E) LACM 43564, 200 mm SL, SW Pacific (M. A. Krag); (F–H) S. radcliffei: (F) ZMUC P77704, 192 mm, S Atlantic (M. A. Krag); (G) ZMUC P2397445, 945 mm SL, NW Pacific (from left head side, shown sidereversed; M. A. Krag); (H) ZMUC P2397724, 1020 mm SL, NW Pacific (M. A. Krag). All otoliths from right side of head if not otherwise indicated. Dotted lines with arrows indicate the approximate measurement positions for ostium width (left side of figure) and sulcus length (right side of figure). Length of black or white scale bars is 5 mm.

FIG. 4. Relationships between morphological characters in the four species of Spectrunculus.