Lucigadus nigromarginatus (Smith & Radcliffe

Nakayama, Naohide, 2020, Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph, Megataxa 3 (1), pp. 1-383 : 237-238

Lucigadus nigromarginatus (Smith & Radcliffe in Radcliffe, 1912)

[No Japanese name]

( Figs. 157–159 ; Appendix 3-9E)

Macrourus nigromarginatus Smith & Radcliffe in Radcliffe, 1912:114, pl. 24, fig. 2 [original description; holotype: USNM 72930 , from near Simaluc Island, 5º33′15ʺN, 120º15′30ʺE, in 303 ftm (554 m); numerous paratypes] .

Lucigadus lucifer (not Smith & Radcliffe in Radcliffe 1912): Chiou et al. 2004a:45, fig. 15 (brief description; 1 spec. from Nanfang-ao ; first record from Taiwan).

Ventrifossa lucifer (not Smith & Radcliffe in Radcliffe 1912): Chiou et al. 2004a: table 1 (listed; Taiwan).

Ventrifossa nigromarginata: Chiou et al. 2004a : table 1 (listed; first record from Taiwan).

Lucigadus nigromarginatus: Shao et al. 2008b : table 2 (2 spec. listed from northeastern and southwestern Taiwan ); Iwamoto et al. 2015:84 (brief description; 9 spec. from northeastern and southwestern Taiwan, South China Sea, Philippines, and New Caledonia).

Diagnosis. A species of Lucigadus with 10–11 pelvicfin rays; first dorsal fin blackish over anterior 3–4 rays; distal margin of anal fin prominently marked with black anteriorly; snout length 24–28% HL; interorbital width 22–31% HL; height of first dorsal fin 92–107% HL; barbel length 20–26% HL; scales below second dorsal-fin origin 7–9.5; branchiostegal membranes heavily scaled ventrally; body pale overall, without broad dark bands. [Modified from the key to Lucigadus species provided by Iwamoto & Okamoto (2015:372).]

Material examined. 2 specimens. Taiwan: BSKU 98982 (1, 35.2 mm HL, 175+ mm TL), Dong-gang fish market, Pingtung, bottom trawl, coll. H.-C. Ho, 16 Nov. 2007 ; FAKU 204468 (1, 31.0 mm HL, 156+ mm TL), Dong-gang fish market, Pingtung, bottom trawl, coll. N. Nakayama, 27 Feb. 2017 .

Counts and measurements. For counts and measurements see Iwamoto et al. (2015:84) and Iwamoto & Okamoto (2015: table 1).

Size. To about 20 cm TL ( Iwamoto & Okamoto 2015).

Distribution. Known only from the western central Pacific including the Philippines (type locality), Indonesia, China, and Taiwan, at depths of 247–717 m ( Radcliffe 1912; Gilbert & Hubbs 1920; Weber & de Beaufort 1929; Shao et al. 2008a, 2008b). No specimens have been collected within Japan’s EEZ (Appendix 3-9E). Common in Taiwan.

Remarks and comparisons. For further morphological information see the original description given by Smith & Radcliffe (in Radcliffe 1912). In the key to Lucigadus species provided by Iwamoto & Okamoto (2015), L. nigromarginatu s is most similar to L. acrolophus Iwamoto & Merrett, 1997 . According to their study, L. nigromarginatus differs from L. acrolophus in having a shorter snout (24–28% HL vs. 28–32%), a lower first dorsal fin (92–107% HL vs. 108–129%), an apical black spot on the first dorsal fin (vs. anterior third of the fin membrane blackish), and a blackish anterodistal margin of the anal fin (vs. absent).

Figures

FIGURE 157. Fresh specimen of Lucigadus nigromarginatus. FAKU 204468, 31.0 mm HL, 156+ mm TL, Dong-gang fish market, southwestern Taiwan, South China Sea. (A) Lateral view; (B) dorsal and (C) ventral views of the head and trunk. [Photos: N. Nakayama]

FIGURE 158. Preserved specimen of Lucigadus nigromarginatus. BSKU 98982, 35.2 mm HL, 175+ mm TL, Dong-gang fish market, southern Taiwan, South China Sea, ca. 200–300 m depth. (A) Lateral view; (B) dorsal and (C) ventral views of the head and trunk. [Photos: N. Nakayama]

FIGURE 159. Scanning electron micrographs showing a body scale (from the dorsum below the interdorsal space) of Lucigadus nigromarginatus. BSKU 98982, 35.2 mm HL. (A) View from above; (B) oblique view. [Photos: N. Nakayama]