Macrourus carinatus (Günther 1878), Gunther, 1878

Mcmillan, Peter, Iwamoto, Tomio, Stewart, Andrew & Smith, Peter J, 2012, A new species of grenadier, genus Macrourus (Teleostei, Gadiformes, Macrouridae) from the southern hemisphere and a revision of the genus, Zootaxa 3165, pp. 1-24 : 12-15

Macrourus carinatus (Günther 1878)

Coryphaenoides carinatus Günther, 1878: 28 . Holotype BMNH 1887.12.7.89, near Prince Edward Island, Challenger station 145A, 310 fathoms [567 m].

Macrurus carinatus —Günther, 1887: 137, Pl. 33 (redescribed, illustrated).

Macrourus carinatus — Trunov & Konstantinov, 1986: 125–135 (described, illustrated, compared with M. holotrachys , in Russian, English summary). Trunov & Konstantinov, 1989: 54–65 (108 specimens, description, in Russian, English summary). Trunov & Konstantinov, 1990: 44–54 (described, illustrated, key, in Russian, English summary). Iwamoto in Cohen et al., 1990: 233–240 (described, illustrated, key). Iwamoto in Gon & Heemstra, 1990: 192, 202–206 (described, illustrated, key).

Diagnosis. Ventral surface of the head mostly scaled, except for scaleless areas anterior to the rear angles of the mouth and on the anterior half of the lower jaw. Pelvic fin with 8 rays, rarely 7 or 9. Lower jaw with 2–5 rows of small uniform-sized teeth reducing to a single row posteriorly. Upper jaw with 3–6 rows of teeth with outer row enlarged relative to those of inner rows. Body scales large, 19–25 in a diagonal row from anal fin origin to lateral line. Pyloric caeca 13–20.

Specimens examined. Holotype. BMNH 1887.12.7.89 (111 mm HL, 515 mm TL); near Prince Edward Is., southeast Indian Ocean, 41° 46' S, 38° 10' E, 310 fm (567 m), Challenger stn. 145A (dredge), 27 Dec. 1873.

Non-type specimens (45). ISH 243/71 (37 mm HL, 173 mm TL), south Atlantic, 48° 54' S, 56° 52' W, 830 m, Walter Herwig stn. 295/71, 14 Feb 1971; ISH 1127/6 (3, 85– 108 mm HL, 375–395+ mm TL) & ISH 1127/7 (140 mm HL, 630 mm TL), southeast Atlantic, 36° 0' S, 52° 57' W, 800 m, Walter Herwig stn. 237/66; ISH 1216/66 (106 mm HL, 480+ mm TL), southeast Atlantic Ocean, 39° 59' S, 56° 6' W, 300 m, Walter Herwig stn. 264/66; ISH 1357/66 (4, 71– 94 mm HL, 302+–420+ mm TL), southeast Atlantic, 48° 16' S, 60° 12' W, 400 m, Walter Herwig stn. 317/66, 26 Jun 1966; NMNZ P.006647 (142 mm HL, 610+ mm TL), Chatham Rise, NZ, 43º 11' S, 174º 59' E, 298–422 m, RV Shinkai Maru , SM 7501/1-2, bottom trawl, 23 Jun 1975; NMNZ P.006890 (157 mm HL, 716 mm TL), Bounty Platform, NZ, 48º 28' S, 179º 46' E, 565–582 m, RV Shinkai Maru , SM 7603/095, bottom trawl, 26 May 1976; NMNZ P.007004 (139 mm HL, 628 mm TL), Campbell Plateau, NZ, 46º 55' S, 170º 15' E, 960 m, RV Shinkai Maru , SM 7603/390, bottom trawl, 18 Sep 1976; NMNZ P.007561 (140 mm HL, 623 mm TL), Campbell Plateau, NZ, 50º 31' S, 173º 53' E, 772 m, RV Kaiyo Maru, KM 78/69/028, bottom trawl, 19 Jan 1978; NMNZ P.008401 (2, 174– 181 mm HL, 813–814 mm TL), Chatham Rise, NZ, 42º 50' S, 176º 58' W, 892–907 m, RV Wesermünde, WES 7903/044, bottom trawl, 0 3 Jun 1979; NMNZ P.009486 (64 mm HL, 272 mm TL), East of South Is., NZ, 44º 48' S, 173º 11' E, 950–1100 m, FV Ahktuba, 14 Nov 1979; NMNZ P. 011285 (140 mm HL, 582+ mm TL), Northeast North Is. NZ, 34º 44' S, 174º 28' E, 745–750 m, FV Kalinovo, K 8101/008, bottom trawl, 21 Nov 1981; NMNZ P. 011292 (144 mm HL, 676 mm TL), Chatham Rise, NZ, 44º 6' S, 178º 31' E, 930–975 m, FV Kalinovo, K 8101/116, bottom trawl, 12 Dec 1981; NMNZ P. 011434 (53 mm HL, 246 mm TL), Chatham Rise, NZ, 44º 13' S, 178º 58' E, 1005–1030 m, FV Kalinovo, K 8101/083, bottom trawl, 0 6 Dec 1981; 12115 (161 mm HL, 742 mm TL), Campbell Plateau, NZ, 51º 52' S, 173º 23' E, 646–651 m, RV Shinkai Maru , SM 82/--/173, bottom trawl, 19 Apr 1982; NMNZ P. 012116 (2, 165– 174 mm HL, 704–793 mm TL), Campbell Plateau, NZ, 53º 26' S, 170º 32' E, 631–644 m, RV Shinkai Maru , SM 82/--/154, bottom trawl, 13 Apr 1982; 12930 (146 mm HL, 625 mm TL), Chatham Rise, NZ, 42º 38' S, 176º 36' E, 1135–1140 m, FV Kaltan, KTN 8201/145, bottom trawl, 27 Aug 1982; NMNZ P.014769 (124 mm HL, 512 mm TL), Challenger Plateau, NZ, 42º 39' S, 169º 8' E, 1029–1125 m, FV Arrow, ARR 8303/018, bottom trawl, 15 Oct 1983; NMNZ P.014880 (158 mm HL, 721 mm TL), East of South Is., NZ, 44º 45' S, 173º 6' E, 902–922 m, RV James Cook, JCO 8315/017, bottom trawl, 27 Nov 1983; NMNZ P.015831 (30 mm HL, 143 mm TL), east of South Is., NZ, 44º 50' S, 172º 49' E, 1180–1184 m, RV James Cook, JCO 8410/009, bottom trawl, 0 9 Jun 1984; NMNZ P. 021709 (109 mm HL, 482 mm TL), Bounty Platform, NZ, 48º 25' S, 178º 36' E, 734–741 m, RV Shinkai Maru , SM 8202/209, bottom trawl, 28 Apr 1982; NMNZ P. 021710 (107 mm HL, 445 mm TL), Chatham Rise, NZ, 42º 47' S, 177º 17' W, 906–914 m, RV Wesermünde, WES 8001/ 0 0 3,, 10 Jul 1980; NMNZ P. 021711 (117 mm HL, 543 mm TL), Chatham Rise, NZ, 42º 50' S, 177º 10' W, 917– 978 m, RV Wesermünde, WES 8001/112, bottom trawl, 10 Aug 1980; NMNZ P. 023014 (35 mm HL, 166 mm TL), east of South Is., NZ, 44º 50' S, 172º 49' E, 1180–1184 m, RV James Cook, JCO 8410/009, bottom trawl, 0 9 Jun 1984; NMNZ P.023500 (90 mm HL, 381 mm TL), Campbell Rise, NZ, 53º 45' S, 170º 4' E, 875–875, RV Wesermünde, WES 7902B/139, bottom trawl, 13 May 1979; NMNZ P.024200 (120 mm HL, 501 mm TL), South Tasman Rise, 47º 12' S, 147º 48' E, 1024–1056 m, FV Amaltal Explorer, OBS 0314/015, bottom trawl, 12 Jan 1989; NMNZ P.026961 (2, 144– 155 mm HL, 620–707 mm TL), Campbell Plateau, NZ, 51º 58' S, 167º 39' E, 774–781 m, FV Amaltal Explorer, AEX 9002/042, bottom trawl, 14 Nov 1990; NMNZ P.026991 (137 mm HL, 622 mm TL), Bounty Platform, NZ, 47º 37' S, 178º 1' E, 840–846 m, FV Amaltal Explorer, AEX 9002/155, bottom trawl, 0 9 Dec 1990; 34622 (76 mm HL, 332 mm TL), Chatham Rise, NZ, 45º 24' S, 173º 59' E, 1373– 1373 m, RV Tangaroa , NZOI S0154, 7 Oct 1979; NMNZ P.034730 (104 mm HL, 446 mm TL), Chatham Rise, NZ, 45º 46' S, 174º 31' E, 1586– 1586 m, RV Tangaroa , NZOI S0151, Oct 1979; NMNZ P.035714 (141 mm HL, 625 mm TL), South Tasman Rise, 47º 28' S, 148º 48' E, 874–898 m, FV Arrow, OBS 1137/005, bottom trawl, 0 7 Aug 1998; NMNZ P.038558 (144 mm HL, 672 mm TL), Pacific Antarctic Ridge, 63º 9' S, 174º 14' E, 866–1241 m, FV San Aotea II, OBS 1595B/171A, bottom longline, 0 5 May 2002; NMNZ P. 040601 (2, 174– 177 mm HL, 805–815 mm TL), Pacific Antarctic Ridge, 64º 44' S, 172º 50' E, 1114 m, FV Avro Chieftain, OBS 1742/090, bottom longline, 0 8 Apr 2003; NMNZ P. 042354 (133 mm HL, 572 mm TL), Pacific Antarctic Ridge, 64º 6' S, 177º 20' E, 1508–1543 m, FV Janas, OBS 1593B/226, bottom longline, 23 May 2002; NMNZ P. 042655 (154 mm HL, 682 mm TL), Ross Sea, 71º 52' S, 173º 9' E, 1004–1038 m, FV Avro Chieftain, OBS 2330/039, bottom longline, 10 Jan 2007; NMNZ P. 042961 (45 mm HL, 218 mm TL), Chatham Ridge, NZ, 44º 6' S, 178º 38' E, 1010–1025 m, FV Kalinovo, K 8101/078, bottom trawl, 0 5 Dec 1981.

Counts and measurements ( Tables 1 –2).

Description ( Figures 6–7 , Tables 1 –2). Head large, length 4.1 to 4.8 into total length. Scutes on head ridges armed with short spinules. Short snout, length less than orbit diameter, tipped with a moderate scute. Prominent scutes on angles of snout where nasal ridge meets suborbital ridge. Mouth close to snout tip, with upper jaw about same length as orbit diameter, posterior end of premaxilla below about mid-orbit. Chin barbel about one-third of orbit diameter.

Upper jaw teeth in 5–6 rows with outer teeth noticeably enlarged relative to those of inner rows. Lower jaw teeth with about 3 rows at tip, reducing to 1–2 posteriorly, outer teeth not noticeably enlarged.

Origins of pectoral and pelvic fins about on same vertical, and both slightly in advance of origin of first dorsal fin.

Body scales large, moderately thick, deciduous. Those between lateral line and first dorsal fin base with a long central row of enlarged spinules with 4–5 short lateral ridges of smaller spinules. Dorsal head covered with spinulated, adherent scales, except for scaleless area around nostrils extending dorsally to nasal ridge and ventrally to suborbital ridge. Ventral surface of head anterior to the rear angles of the mouth scaleless. Numerous rows of small embedded flat scales lacking spinules at posterior end of ventral surface of head, extending forward to about midorbit and reducing to a few rows anteriorly. Small scales on about rear one-third to half of lower jaw.

Fresh colour of head and body pale greyish-brown with slight greenish iridescent sheen on sides of head and trunk. No obvious dark abdominal area in large individuals. Lining of mouth greyish and gill cavity blackish. Ventral surface of head greyish-brown. Fins greyish-brown. Small individuals have white-tipped dorsal fin and darker middle half of fin. Preserved specimens pale brownish overall.

Size. To at least 815 mm TL.

Distribution ( Figure 5 B). Widespread in temperate to Subantarctic waters of the southern hemisphere and northern Southern Ocean including South Atlantic Ocean off east coast of South America, southern Africa ( Iwamoto & Anderson, 1994), south Indian Ocean including Crozet and Kerguelen Islands ( Duhamel, 1997), Prince Edward Island, southern Australia, South Tasman Rise, South Pacific Ocean ( New Zealand, Pacific-Antarctic Ridge), at 300–1600 m. One large specimen (NMNZ P. 042655) captured on a longline in the Ross Sea is the first verified specimen of the species from the Ross Sea. The capture data for the specimen was checked against observer records and a photograph of the freshly captured specimen is evidence that the record is genuine. The presence of only a single Macrourus carinatus specimen amongst the numerous M. caml and M. whitsoni specimens collected from the Ross Sea by New Zealand observers suggests that this record is unusual.

Comparisons and remarks (Table 3). Macrourus caml and M. whitsoni also have a mostly scaled ventral surface of the head but M. caml has smaller body scales, 30–40 in a diagonal row from anal fin origin to lateral line, more pyloric caeca 20–37, and is much darker, often blackish-brown body and head in large individuals. M. whitsoni has small body scales, 36–45 in a diagonal row from anal fin origin to lateral line, and 9 pelvic fin rays. M.

holotrachys has a mostly scaleless ventral surface of the head, and a much more robust squamation with thick, adherent body scales armed with a strong central spinule row.

Trunov and Konstantinov (1989) examined numerous specimens of Macrourus carinatus and their counts of pelvic fin rays, pyloric caeca, and scales from anal fin origin to lateral line agree closely with our counts for the same species ( Table 4 ). Macrourus carinatus is probably the most commonly captured species in the genus in the southern hemisphere, although accurate records of its capture are uncertain because of likely confusion with other species in the genus. It also appears to have a more northern range than the other three southern hemisphere Macrourus species.

Figures

FIGURE 5. Distribution maps for southern hemisphere species of Macrourus based only on specimens examined in this study. (A) M. caml sp. nov.; (B) M. carinatus; (C) M. holotrachys; (D) M. whitsoni.

FIGURE 6. Macrourus carinatus. NMNZ P. 021711 (117 mm HL, 543 mm TL), New Zealand slope 42 º 49.6 ' S, 177 º 10.1 ' W, 917 – 978 m, 10 Aug. 1980. (A) Lateral view of head and trunk; (B) ventral view of head and trunk, drawn by Michelle Freeborn (Te Papa); (C) photo of body scale between lateral line and first dorsal fin base by Peter Marriott (NIWA).

FIGURE 7. Macrourus carinatus. Specimen not retained (about 110 mm HL, 540 mm TL), New Zealand slope, 44 ° 20.35 ' S, 178 ° 59.88 ' W, 748 – 755 m, 8 Jan. 2007, photo of freshly caught specimen by Peter Marriott (NIWA).