Bigeye grenadier

description

Description (Figures 8 – 9, Tables 1 – 2). Head large, length 3.6 to 4.7 into total length. Very strong scutes on head ridges, armed with strong spinules. Slightly elongated snout, length less than orbit diameter, tipped with a strong scute. Prominent strong scutes on angles of snout where nasal ridge meets suborbital ridge. Upper jaw about same length as orbit diameter, posterior end of premaxilla below or just behind mid-orbit. Chin barbel about onethird of orbit diameter. Teeth in both jaws small, pointed. Upper jaw teeth in 4 – 5 rows with outer teeth not noticeably enlarged relative to those of inner rows. Lower jaw with 3 – 4 rows at tip, reducing to 2 – 3 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, thick, adherent. Those between lateral line and first dorsal fin base with a long central row of enlarged strong spinules with 3 – 5 lateral ridges that lack spinules. Scales lateroventrally on body and tail with a central row of strong spinules. Dorsal head covered with heavy, spinulated, adherent scales, except for scaleless area around

A new species of grenadier, genus Macrourus (Teleostei, Gadiformes, Macrouridae) from the southern hemisphere and a revision of the genus

diagnosis

Diagnosis. Ventral surface of the head entirely or mostly scaleless but up to 8 small patches of scales (usually less than about 10 small scales per patch) may be present at the posterior end of head, beside articulation of lower jaw and beside posterior end of premaxilla, and rarely posteriorly on lower jaw. Pelvic fin with 8 or 9 rays (rarely 10). Lower jaw with 2 – 5 rows of small uniform-sized teeth reducing to 1 or 2 rows posteriorly. Upper jaw with 4 – 6 rows of small, uniform-sized teeth. Body scales large, thick, adherent, with a central row of strong spinules, 18 – 26 scales in a diagonal row from anal fin origin to lateral line. Pyloric caeca 9 – 16. Specimens examined. Holotype. BMNH 1887.12.7.87 (50 mm HL, 220 mm TL), south east Atlantic Ocean east of Rio de la Plata, 37 ° 17 ' S, 53 ° 52 ' W, 600 fm (1097 m), Challenger stn. 320, 14 Feb 1876. Non-type specimens (29, all taken by bottom longline). NMNZ P. 036987 (143 mm HL, 640 mm TL), South Georgia, 54 º 0 ' S, 39 º 0 ' W, 1300 – 2000 m, Apr 1997; NMNZ P. 038550 (153 mm HL, 681 mm TL), NMNZ P. 038555 (185 mm HL, 802 mm TL), Pacific-Antarctic Ridge, 64 º 6 ' S, 177 º 20 ' E, 1508 – 1543 m, FV Jana s, Obs 1593 b / 226, 2

A new species of grenadier, genus Macrourus (Teleostei, Gadiformes, Macrouridae) from the southern hemisphere and a revision of the genus

distribution

Distribution (Figure 5 C). Probably widespread in temperate to Subantarctic waters of the southern hemisphere and northern Southern Ocean including the South Atlantic Ocean off the east coast of South America, South Georgia, Discovery Tablemount (Golovan & Pakhorukov, 1983; Trunov, 1986), southwest Pacific Ocean (Macquarie Ridge, Pacific-Antarctic Ridge), southeast Pacific Ocean off Chile (Ruiz R. & Oyarzun G., 1993), De Gerlache Seamount, at 850 – 2000 m. Two specimens captured on the north end of the Macquarie Ridge (NMNZ P. 039949, P. 039957) represent a new record of the species from the New Zealand EEZ. Comparisons and remarks (Table 3). Macrourus caml, M. carinatus, and M. whitsoni all have a mostly scaled ventral surface of the head. M. caml, and M. whitsoni have much smaller body scales, 30 – 40 and 36 – 45 respectively in a diagonal row from anal fin origin to lateral line. M. carinatus has an outer row of enlarged teeth in the upper jaw and is generally pale to medium brown. M. berglax is known only from the northern hemisphere north of about 37 ° N, has pelvic fin with 8 (rarely 9) rays, large body scales with 13 – 17 diagonal rows from anal fin origin to lateral line, a

A new species of grenadier, genus Macrourus (Teleostei, Gadiformes, Macrouridae) from the southern hemisphere and a revision of the genus