Spicomacrurus Okamura, 1970

Nakayama, Naohide, 2020, Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph, Megataxa 3 (1), pp. 1-383 : 277-278

Genus Spicomacrurus Okamura, 1970

[Japanese name: Yaridara-zoku]

Spicomacrurus Okamura, 1970a:63 (subgenus of Hymenogadus ; type species: Hymenocephalus kuronumai Kamohara, 1938 , by original designation).

Diagnosis. Anus immediately anterior to anal-fin origin, surrounded by narrow periproct. Ventral striae, consisting of fine, parallel black lines over silvery layer on each side of isthmus, shoulder girdle, most of chest, and posterior to pelvic fins. Gular region covered with netlike pattern of black epithelium. Light organ developed as long tube, extending from anus to slightly anterior to pelvic-fin bases; small lens at each end of light organ. Second spinous ray of first dorsal fin smooth along its leading edge. Pelvic-fin rays 8–10, outer ray greatly elongate and flattened with narrow ribbon-like flange on free distal portion. Teeth all small, in narrow villiform bands in both jaws. Trunk cylindrical or weakly compressed. Head bones not fragile. Nasal bones stout, forming dorsoventrally flattened, lateral and medial processes. Chin barbel present. Body scales large, highly deciduous, covered with needle-like spinules; radial grooves developed anteriorly; reticulate structure absent. Branchiostegal rays 7. All species small, less than 25 cm TL. [From Iwamoto et al. (2011) and Schwarzhans (2014).]

Remarks. Spicomacrurus was originally established by Okamura (1970a) as a monotypic subgenus of Hymenocephalus Giglioli, 1884 , with the type species being S. kuronumai ( Kamohara, 1938) . Iwamoto et al. (2011) elevated this group to full generic rank after their discovery of two new species from the southwestern Pacific. In addition to S. kuronumai , the genus includes the following three species known only from the Southern Hemisphere: S. adelscotti Iwamoto & Merrett, 1997 recorded from Fiji (type locality) and Western Australia; S. dictyogadus Iwamoto, Shao & Ho, 2011 represented by only the holotype collected from Vanuatu; and S. mccoskeri Iwamoto, Shao & Ho, 2011 so far known from the Chesterfield Plateau in the Coral Sea.