Pseudonezumia japonicus

diagnosis

Diagnosis. Underside of snout broadly naked above upper lip; spinules on body scales supported by narrowly developed buttresses; transverse scale rows below first dorsal-fin origin 8.5 – 12.5, below first dorsal-fin midbase 7 – 12; orbit diameter 22 – 28 % HL; preoral length 20 – 26 % HL; postorbital length 42 – 48 % HL; orbit – preopercle distance 34 – 43 % HL; interorbital width 29 – 36 % HL; barbel length 8 – 13 % HL; caudal depth at base of 40 th anal-fin ray 27 – 34 % HL; body uniformly dusky to paler brown, except for darker abdomen and black periproct.

Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph

discussion

Remarks. For further morphological information see the original description given by Okamura (1970 a). Pseudonezumia japonica was described from a single specimen collected from off Mito, Ibaraki Pref., Japan (Fig. 189), as a new genus and species of grenadiers. Okamura (1970 a) considered this species to be quite different from other grenadiers in having eight branchiostegal rays (vs. six or seven). However, an examination of additional specimens from the type locality showed that the number is usually seven, and only rarely eight. Relationships and comparisons. Pseudonezumia japonica is closely similar to P. cetonuropsis (Gilbert & Hubbs, 1916) also known from Japan. These two species are tentatively regarded as valid in this study, but a further investigation based on additional material may arrive at a different conclusion, namely, P. japonica is synonymized with P. cetonuropsis (see the Relationships and comparisons of the latter species).

Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph

distribution

Distribution. Restricted to Japan (Appendix 3 - 11 E). Depth range 1453 ‾ 2005 m.

Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph

materials_examined

Material examined. 31 specimens. Holotype of Pseudonezumia japonicus: BSKU 14203 (46.0 mm HL, 303 mm TL), off Mito, Ibaraki Pref., Japan, 36.3189 ºN, 141.2333 ºE, 1690 m, 3 Dec. 1967. Non-types: Japan: BSKU 56944 (1, 47.2 mm HL, 325 mm TL), BSKU 56945 (1, 43.6 mm HL, 258 + mm TL), BSKU 56946 (1, 46.7 mm HL, 290 + mm TL), BSKU 56947 (1, 44.9 mm HL, 280 + mm TL), BSKU 56948 (1, 48.7 mm HL, 274 + mm TL), BSKU 56949 (1, 38 + mm HL, 274 + mm TL), BSKU 56950 (1, 48.8 mm HL, 302 + mm TL), BSKU 56951 (1, 42.6 mm HL, 306 mm TL), BSKU 56952 (1, ca. 39 mm HL, 253 + mm TL), BSKU 56953 (1, 43.8 mm HL, 214 + mm TL), BSKU 56954 (1, 39.9 mm HL, 287 + mm TL), BSKU 56955 (1, 36.5 mm HL, 244 + mm TL), BSKU 56956 (1, 43.5 mm HL, 285 + mm TL), BSKU 56957 (1, 47.3 mm HL, 289 + mm TL), BSKU 56958 (1, 49.5 mm HL, 332 + mm TL), BSKU 56959 (1, 48.5 mm HL, 286 + mm TL), BSKU 56960 (1, 47.0 mm HL, 224 + mm TL), BSKU 56961 (1, 44.4 mm HL, 307 + mm TL), BSKU 56963 (1, 47.8 mm HL, 331 + mm TL), BSKU 56964 (1, 47.4 mm HL, 215 + mm TL), BSKU 56965 (1, ca. 45 mm HL, 288 + mm TL), BSKU 56966 (1, 43.8 mm HL, 273 + mm TL), BSKU 56967 (1, 43.1 mm HL, 297 mm TL), BSKU 56969 (1, 40.5 mm HL, 272 mm TL), BSKU 56971 (1, ca.

Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph