Etmopterus abernethyi Garrick 1957
Year: 2025
Type: other
Abstract: Etmopterus abernethyi Garrick, 1957 (Figs 2, 3 A, 4 A, 5 A, 6 A, C, 7 A, C, 8; File S 2: Table S 1) Etmopterus abernethyi Garrick, 1957: 183, figs 3–4 (holotype: NMNZ P.01951, from off south Kaikoura, New Zealand; 1 paratype from off south Kaikoura, New Zealand); Yamakawa et al. (1986): 199 (listed); Last and Stevens (1994): 82 (listed); Last and Stevens (2009): 82 (listed); Dyldin (2015): 55 (listed); Ebert et al. (2021): 11 (listed). Etmopterus abernathyi [sic]: Bigelow and Schroeder (1957): 54, 59, 62 (in text and key); Compagno (1984): 79 (listed). Etmopterus lucifer (not Jordan & Snyder, 1902): Last and Stevens (1994): 81–82, plate 7, fig. 8.23 (listed from around Australia and New Zealand, with brief description); Last and Stevens (2009): 82, fig. 10.9 (listed from around Australia and New Zealand, with brief description); Straube et al. (2013): 261 (listed, New Zealand); Last and Stevens (2015): 143, fig. 25.3 (1 specimen, NMNZ P.037103 from southeastern Tuatoru Knoll, northern New Zealand); Weigmann (2016): 896 (listed, southwestern Pacific); Duchatelet et al. (2021): 825, fig. 2 (figure showing ventral side of body with bioluminescence). Materials examined. 51 specimens. Holotype: NMNZ P.01951, immature male 330 mm TL, off south Kaikoura, New Zealand, 42°58'S, 173°40'E, 366 m, November 1955. Paratype: MCZ 39714, female 267 mm TL, off south Kaikoura, New Zealand, 42°50'S, 173°41'E, 180 m, February 1956. Non-types: AMS E.5530, female 355 mm TL, south of Gabo Island, southeastern Australia, 37°00'S, 149°54'E, 6 October 1914; AMS E.5531, female 301 mm TL, southeast of Gabo Island, southeastern Australia, 37°00'S, 150°00'E, 15 September 1914; AMS I.12820, mature male 403 mm TL, Great Australian Bight, southern Australia, 32°00'S, 129°28'E, 14 May 1913; AMS I.15994 -003, female 346 mm TL, south of Eden, southeastern Australia, 37°43'S, 150°15'E, 30 July 1971; AMS I.20096 -003, female 389 mm TL, southeast of Gabo Island, southeastern Australia, 37°38'S, 150°20'E, 30 November 1977, coll. K. Graham; AMS I.26000 -009, female 422 mm TL, off Broken Bay, southeastern Australia, 33°30'S, 152°09'E, 12 February 1986, coll. K. Graham; AMS I.40290 -003, juvenile male 206 mm TL, off Bermagui, southeastern Australia, 36°27'S, 150°18'E, 2 May 2000, coll. K. Graham; AMS I.42746 -003 (3 specimens), mature males 388–402 mm TL, western Norfolk Ridge, Tasman Sea, 33°49'S, 167°03'E, 27 May 2003; AMS I.44903 -001 (2 specimens), 323–363 mm TL, Taupo Seamount, Tasman Sea, 33°21'S, 156°07'E, 11 September 2009, coll. K. Graham; AMS I.44991 -004 (4 specimens), 386–415 mm TL, north of Sydney closure, southeastern Australia, 33°39'S, 151°57'E, 15 September 2009, coll. K. Graham; AMS I.45667 -013, mature female 432 mm TL, Ulladulla slope, southeastern Australia, 35°25'S, 150°51'E, 4 November 2011, coll. K. Graham; AMS I.46064 -001 (2 of 5 specimens), mature female 473–492 mm TL, Gascoyne Seamount, southeastern Australia, 36°10'S, 156°12'E, 11 June 2012, coll. K. Graham; CAS 218737 (2 specimens), 307–377 mm TL, Tasman Sea, 32°42'S, 162°34'E, 850–872 m, 25 May 2003; CSIRO H 2353-01, mature male 395 mm TL, northwest of Bunbury, western Australia, 32°52'S, 114°35'E, 517 m, 25 December 1989; CSIRO H 6042-13, female 472 mm TL, CSIRO H 6042-14, female 396 mm TL, CSIRO H 6042-15, female 420 mm TL, Lord Howe Rise, Tasman Sea, 32°41'S, 162°33'E, 855–874 m, 25 May 2003; CSIRO H 6044-09, immature male 209 mm TL, Lord Howe Rise, Tasman Sea, 34°01'S, 162°36'E, 812–818 m, 25 May 2003; CSIRO H 7051-14, female 451 mm TL, east of Wollongong, southeastern Australia, 34°18'S, 151°25'E, 440 m, 20 September 2009; CSIRO H 7052-5, immature male 287 mm TL; CSIRO H 7052-6, immature male 321 mm TL; CSIRO H 7052-7, female 333 mm TL; CSIRO H 7052-8, female 405 mm TL; CSIRO H 7052-9, female 388 mm TL; H 7052-10, female 386 mm TL; CSIRO H 7052-11, female 437 mm TL, northeastern Flinders Island, Tasman Sea, 39°34'S, 148°50'E, 450–570 m, 3 October 2009; CSIRO H 7059-03, female 406 mm TL; CSIRO H 7059-04, female 438 mm TL, east of Sydney, southeastern Australia, 33°40'S, 151°55'E, 530 m, 15 September 2009; CSIRO H 7174-01, juvenile male 383 mm TL, Lord Howe Rise, Tasman Sea, 34°05'S, 162°49'E, 560 m, 14 April 2003; CSIRO H 8866-01, female 391 mm TL, east of Eaglehawk Neck, Tasman Sea, 43°06'S, 148°15'E, 490 m, 16 February 2022; CSIRO H GT 6242, female 372 mm TL, presumably Australia; CSIRO T 598, mature male 371 mm TL, Great Australian Bight, southern Australia, 33°26'S, 129°05'E, 425–545 m, 4 June 1983; NMMZ P.20893 (1 of 3 specimens), mature male 329 mm TL, southern Mernoo Bank, New Zealand, 43°44'S, 174°56'E, 423 m, 6 May 1987; NMMZ P.27020, female 527 mm TL, Auckland Island Rise, New Zealand, 49°40'S, 168°25'E, 636–648 m, 20 October, 1990; NMNZ P.031152 (1 of 3 specimens), pregnant female 439 mm TL, northeastern Chatham Rise, New Zealand, 42°52'S, 178°09'E, 505–510 m, 26 May 1994; NMMZ P.47326, female 461 mm TL, central southern Chatham Rise, New Zealand, 44°21'S, 178°15'W, 507–513 m, 31 December 2006; NMNZ P.054695, female 319 mm TL, southern Hokitika Canyon, New Zealand, 42°48'S, 169°51'E, 555 m, 4 August 2012; NMNZ P.057055, female 235 mm TL, Hokitika Canyon, New Zealand, 42°51'S, 170°31'E, 650 m, 27 July 2014; NMNZ P.058027, female 294 mm TL, east coast of North Island, New Zealand, 15 June 2015; NMMZ P.60912, female 461 mm TL, Chatham Rise, New Zealand, 43°47'S, 178°18'W, 407–416 m, 27 July 2015. USNM 318374 (1 of 7 specimens), immature male 240 mm TL, Mernoo Bank, New Zealand, 300–800 m, May 1990. Diagnosis. A moderately large Etmopterus belonging to the E. lucifer group by having elongated anterior and posterior branches of lateral flank marking, and differing from other members by the following combination of characters: hook-like dermal denticles not overlapping each other, in well-defined rows; origin of second dorsal fin anterior to origin of base of flank-marking; infracaudal marking connected with caudal-fin base marking through pair of luminous lines; posterior caudal-fin marking long, length 30.2–46.5 % caudal-fin length; and ventral pectoral marking strongly curved. Redescription. Morphometric information is provided in File S 2 (Table 1). Proportional measurements and tooth counts are provided as ranges for the paratype and the non-types, followed by the holotype in parentheses. A precise tooth count of the lower jaw teeth is not possible in the holotype as several teeth are missing. Trunk sub-cylindrical, body width narrower than to slightly wider than body height; abdomen longer than lower caudal peduncle; head subconical, slightly depressed. Snout moderately short (Fig. 2), narrowly rounded in lateral and dorsal view. Eye oval. Spiracle bean-shaped. Gill openings small, nearly straight. Mouth broad, very slightly arched. Teeth dissimilar in upper and lower jaw, with strong ontogenetic change and sexual dimorphism; upper teeth multicuspid, in three functional series; in lower jaw unicuspid, in three series, one functional; lower teeth blade-like, with strongly oblique cusp. No distinctive symphyseal and intermediate teeth. Upper teeth central cusp rather thick; immature males and females with 1–2, rarely 3, cusplets on each side of the upper-teeth cusp, but mature males with 3–4 cusplets, rarely 2 (Fig. 3 A); in mature individuals, longest cusplet length about two-third of the cusp in mature individuals; cusp and cusplets of upper teeth narrowly triangular, lower teeth of mature individuals not erected. Tooth count of upper jaw 22–28 (23), lower jaw 32–42, total count 54–70. First dorsal fin (D 1) long and rather small, with round apex, origin just below to posterior to a vertical line through pectoral-fin (P 1) free rear tip. Second dorsal fin (D 2) larger than D 1, apex angular, posterior margin especially concave, free rear tip moderately elongated; D 2 spine long and curved. P 1 moderate in size, with angular free rear tips, base narrow, posterior margin slightly concave. Pelvic fin (P 2) narrowly triangular. Clasper of mature males rather long. Caudal fin elongate, caudal fork not especially developed; terminal lobe broad. Dermal denticles hook-like, rather high, recurved (Fig. 4 A), widely-spaced, not overlapping, giving a rough texture of the skin, in defined rows; denticles present on underside of snout, except for a broad area around mouth; underside of gill slits fully covered with denticles (small bare patch rarely present between underside of gill slits); P 1 inner margin with a broad naked area, D 1, D 2 and P 2 inner margins with narrow naked areas; denticles present on fin bases; denticles scarcely distributed on fins in juveniles, increasing the coverage to most of the areas of ceratotrichia with increasing size, especially prominent on D 2 (Fig. 5 A). Body lateral side with short, dash-like markings; head dorsal surface with scattered dot-like markings; dorsal contour of the body with a single line of dot-like markings, extending mid-dorsally from about the level of anterior fontanelle to origin of D 2; ventral pectoral marking elongated and arched (Fig. 6 A, C), its tip falling short of P 1 insertion. Flank markings well defined, with elongated anterior and posterior branches; anterior flank marking slender, slightly curved, extending above P 2 origin; posterior flank marking straight, slightly thicker, usually shorter than anterior flank marking (rarely longer than anterior flank marking); anterior flank marking length 92.1–182.5 (132.7) % posterior flank marking; posterior flank marking usually not extending beyond D 2 free rear tip; flank marking base rather narrow, origin well posterior to D 2 origin. Infracaudal marking prominent, extending from flank marking base to about the same level of posterior flank marking tip, connecting to the caudal-base marking by a pair of lines formed by bioluminescent melanophores (Fig. 7 A, C; see also Duchatelet et al. 2021); caudal-base marking broad, with a moderately thick, slender exten
Authors: Ng, Shing-Lai, Straube, Nicolas, Liu, Kwang-Ming, Joung, Shoou-Jeng
Institutions: National Taiwan Ocean University, University of Bergen
Language: English
Subfield: Nature and Landscape Conservation
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6930526469
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