Odontomacrurus murrayi Norman, 1939

Nakayama, Naohide, 2020, Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph, Megataxa 3 (1), pp. 1-383 : 268-270

Odontomacrurus murrayi Norman, 1939

[Japanese name: Kurobozudara]

( Figs. 181–182 ; Appendix 3-11B)

Odontomacrurus murrayi Norman, 1939:49 , text-fig. 18 (original description; holotype: BMNH 1939.5.24.685, from Arabian Sea, in 0–2500 m); Nakayama et al. 2015b:136, figs. 1–2 (first record from Japan; description; 1 spec. from Pacific off Tohoku; new Japanese name: “Kurobouzudara”); Motomura 2020:39 (listed; Japan).

Phalacromacrurus pantherinus Maul & Koefoed, 1950:972 , fig. 1 (original description; holotype: ZMUB 4473 , from northeastern Atlantic , 2600 m wire out; paratypes deposited in ZMUB and MMF).

Diagnosis. As for genus.

Material examined. 1 specimen. Japan: BSKU 104866 (1, 30.0 mm HL, 325+ mm TL), off Kinkazan , 37.9665ºN, 143.2269ºE, 168–204 m, FRV Kaiyo-maru, cr. KY-12-07, sta. 6, coll. K. Uchikawa et al., 16 Dec. 2009 .

Counts and measurements. Based on 1 specimen. Counts: first dorsal-fin rays II,9; pectoral-fin rays i8; pelvic-fin rays 8; gill rakers on first arch (outer/inner) 8–9/11, on second arch 9–10/10–11.

The following measurements are in % of HL, followed by those in % of PRL in parentheses: snout length 34 (47); orbit diameter 24 (33); postorbital length 49 (68); postrostral length 72; orbit–preopercle distance 52 (72); suborbital width 23 (31); upper-jaw length 70 (98); length of rictus 66 (91); length of premaxillary tooth band 55 (76); internasal width 21 (30); interorbital width 32 (44); occipital width 12 (16); body width over pectoral-fin bases 30 (42); body depth at first dorsalfin origin 111 (154); body depth at anal-fin origin 99 (137); prepelvic length 103 (143); preanus length 118 (163); preanal length 136 (189); isthmus–pelvic distance 31 (43); isthmus–anus distance 39 (55); isthmus–anal distance 60 (83); pelvic–anal distance 37 (52); anus–anal distance 25 (35); pelvic-fin length 44 (62); pectoral-fin length 84 (116); predorsal length 105 (146); height of first dorsal fin 52 (71); length of first dorsal-fin base 42 (59); interdorsal length 63 (87); length of gill slit 23 (32); length of posterior nostril 6 (8); barbel length 0 (0).

Size. Attains at least 50 cm TL (Marshall 1973).

Distribution. Widely distributed in tropical and temperate waters of the world’s oceans except for the central and eastern Pacific. In Japan, known only from the Pacific off Tohoku at a midwater depth of 168–204 m (Appendix 3-11B). Generally confined to mesopelagic and bathypelagic depths (see also Nakayama et al. 2015b). Very rare in the northwestern Pacific.

Development. For a full description of juveniles see Maul & Koefoed (1950; original description of Phalacromacrurus pantherinus ) and Endo (1997). The ontogeny of juveniles was also detailed by Marshall (1964).

Remarks. Odontomacrurus murrayi was recently recorded from Japan by Nakayama et al. (2015b), who provided a full description of the Japanese specimen, with comments on the geographic and bathymetric distribution of this species.

Genus Pseudocetonurus Sazonov & Shcherbachev, 1982

[No Japanese name]

Pseudocetonurus Sazonov & Shcherbachev, 1982:712 (type species: Pseudocetonurus septifer Sazonov & Shcherbachev, 1982 , by original designation).

Diagnosis. Anus surrounded by narrow periproct, situated midway between anal-fin origin and pelvic-fin bases. Small dermal window of light organ anterior to periproct. Pelvic-fin rays 8–10. Infraorbital ridge not connected with preopercular ridge, separated by distinct gap. Second spinous ray of first dorsal fin smooth along its leading edge. Head large, with broad interorbital space (33–44% HL). Chin barbel present but small, length less than 10% HL. Teeth small, in narrow tapered band in upper jaw, uniserial in lower jaw. Head fully covered with small, unmodified scales. Body scales covered with long, erect, needle-like spinules in quincunx order; buttresses of scale spinules scarcely developed; no reticulate structures on scale surface. Grooved lateral line absent or present. Cephalic sensory canals notably broad, but lacking open pores. Pyloric caeca short, 22–34. Branchiostegal rays 7. Body uniformly dark. [Modified from Sazonov & Shcherbachev (1982) and Sazonov & Iwamoto (1992).]

Remarks. Pseudocetonurus was established by Sazonov & Shcherbachev (1982) for their new species P. septifer described only from the holotype collected from the Sala y Gomez Ridge in the southeastern Pacific. Sazonov & Iwamoto (1992) subsequently reported additional specimens of this species from near the type locality (Nazca Ridge) as well as from the Hawaiian Islands. Chiou et al. (2004a) newly recorded P. septifer from Taiwan based on a single specimen obtained at the Da-xi fish market (originally collected from the southwestern part of the East China Sea). However, their specimen was re-identified as P. cf. septifer by Iwamoto et al. (2015).

Pseudocetonurus sp. cf. septifer Sazonov & Shcherbachev, 1982

[No Japanese name]

( Figs. 183–184 ; Appendix 3-11C)

Pseudocetonurus septifer (not Sazonov & Shcherbachev 1982): Chiou et al. 2004a:46, fig. 17, table 1 (brief description; 1 spec. from Da-xi; first record from Taiwan); Shao et al. 2008b: table 2 (1 spec. listed from northeastern Taiwan).

Pseudocetonurus cf. septifer: Iwamoto et al. 2015:97 (brief description; 1 spec. from northeastern Taiwan).

Diagnosis. A species of Pseudocetonurus with grooved lateral line on body and pale oral cavity.

Material examined. 1 specimen. Taiwan: ASIZP 61237 (1, 33.2 mm HL, 144+ mm TL), Da-xi fish market, Yilan, northeastern Taiwan , bottom trawl, coll. M.-L. Qiu, 1 May 2001 .

Counts and measurements. Based on 1 specimen. Counts: first dorsal-fin rays II,9; pectoral-fin rays i18; pelvic-fin rays 8; gill rakers on first arch (outer/inner) 12/18, on second arch 15/17, below first dorsal-fin midbase 6.5.

The following measurements are in % of HL, followed by those in % of PRL in parentheses: snout length 28 (37); orbit diameter 29 (37); postorbital length 49 (64); postrostral length 77; orbit–preopercle distance 53 (69); suborbital width 19 (25); upper-jaw length 46 (61); length of rictus 39 (51); length of premaxillary tooth band 36 (46); preoral length 19 (25); distance between tip and lateral angle of snout 21 (28); snout width 34 (44); internasal width 34 (44); interorbital width 37 (48); body width over pectoralfin bases 33 (44); pectoral-fin length 61 (80); predorsal length 103 (135); length of first dorsal-fin base 22 (28); interdorsal length 47 (61); length of gill slit 27 (36); length of posterior nostril 5 (7); barbel length 2 (3).

Size. To about 14 cm TL.

Distribution. So far known only from the Da-xi fish market in northern Taiwan. Capture depth unknown, but probably between 100 and 650 m (Appendix 3-11C). Very rare.

Remarks. This specimen was originally reported as P. septifer Sazonov & Shcherbachev, 1982 by Chiou et al. (2004a), being the first record of the species from Taiwan. However, Iwamoto et al. (2015:97) re-identified this specimen as P. cf. septifer , based on the presence of a grooved lateral line (vs. absent in P. septifer ). It further differs from P. septifer in that the oral cavity is paler dorsally (vs. blackish). The Taiwanese specimen represents an undescribed species that will be formally described later by the present author.

Figures

FIGURE 181. Fresh specimen of Odontomacrurus murrayi. BSKU 104866, 30.0 mm HL, 325+ mm TL, off Oshika Peninsula, Miyagi Pref., Pacific, 168–204 m depth. Lateral view. [Photo: reproduced from Nakayama et al. (2015b: fig. 1) with permission from the Japanese Society of Systematic Zoology]

FIGURE182.Scanningelectronmicrographsshowingabodyscale(fromthedorsumbelowtheinterdorsalspace)ofOdontomacrurus murrayi. BSKU 104866, 30.0 mm HL. (A) View from above; (B) oblique view. [Photos: reproduced from Nakayama et al. (2015b: fig. 2) with permission from the Japanese Society of Systematic Zoology]

FIGURE 183. Preserved specimen of Pseudocetonurus sp. cf. septifer. ASIZP 61237, 33.2 mm HL, 144+ mm TL, Da-xi fish market, northeastern Taiwan, East China Sea. (A) Lateral view; (B) dorsal and (C) ventral views of head. [Photos: N. Nakayama]

FIGURE 184. Scanning electron micrographs showing a body scale (from the dorsum below the interdorsal space) of Pseudocetonurus sp. cf. septifer. ASIZP 61237, 33.2 mm HL. (A) View from above; (B) oblique view. [Photos: NSMT]