Grenadiers (Teleostei: Gadiformes: Macrouridae) of Japan and adjacent waters, a taxonomic monograph
Author
Nakayama, Naohide
0000-0001-9556-1537
Department of Marine Biology, School of Marine Science and Technology, Tokai University, 3 - 20 - 1 Orido, Shimizu, Shizuoka 424 - 8610, Japan ® naonakayama @ tsc. u-tokai. ac. jp or ®
gadiformes@gmail.com
text
Megataxa
2020
2020-11-05
3
1
1
383
journal article
56026
10.11646/megataxa.3.1.1
1ece557d-068b-465b-809e-0fc1110035b3
2703-3090
6422776
7A95A1DD-0372-4FAC-BA3B-1896386BC710
Comments on Japanese record of
Nezumia burragei
(
Fig. 180
)
Kamohara (1937)
recorded
N. burragei
(
Gilbert, 1905
)
from
Japan
based on a single
350 mm
long specimen obtained at the Mimase fish market,
Kochi
. This is a very rare species, which elsewhere is known only from the
holotype
from Hawaii at a depth of
543–603 m
(USNM 51641,
44.2 mm
HL, 254+ mm TL; examined here). The occurrence of
N. burragei
in
Japan
is quite dubious, considering that no additional specimens have been obtained despite the relatively shallow occurrence of the species and extensive trawl surveys in southern
Japan
over the past several decades. Citing
Kamohara’s (1937)
record, all subsequent authors have believed
N. burragei
to occur in Japanese waters (e.g.,
Matsubara 1955
;
Okamura 1970a
,
1984b
,
1988
;
Nakabo 1993
,
2000
,
2002
;
Shinohara
et al.
2001
;
Nakabo & Kai 2013
). Unfortunately, the voucher specimen of
Kamohara (1937)
was apparently lost during the WWII, which makes it difficult to reconfirm the Japanese record of this species.
However,
Kamohara’s (1937)
specimen appears to be attributable to a different species of
Nezumia
, due to notable differences between his figure (
Fig. 180
) and the
holotype
of
N. burragei
(see
Gilbert 1905
: fig. 260).
Kamohara (1937)
illustrated his specimen as having the ventral surface of the snout only narrowly naked above the upper lip, and the posterior margin of the naked area not extending beyond a vertical through the anterior rim of the orbit. In contrast, the ventral surface of the snout and the lower half of the suborbital area are completely naked in the
holotype
of
N. burragei
, with the hind margin of the naked area extending to above the posterior margin of the upper jaw. The difference between the two specimens is also evident in the dorsal contour of the head.
Kamohara’s (1937)
figure shows that the predorsal contour of his specimen was prominently humped over the nape, whereas in the
holotype
, the dorsal contour of the head is straight from above the orbit to the first dorsal-fin origin.
FIGURE 180.
Drawing of a species of
Nezumia
illustrated by Toshiji Kamohara (deposited at BSKU). The illustrated specimen, which was destroyed during WWII, was the basis for the first Japanese record of
N. burragei
by
Kamohara (1937)
. [Photo: BSKU]
It is most likely that the record of
Kamohara (1937)
represents a misidentification of
N. rara
sp. nov.
described here. Many features of his specimen, including fin-ray counts, head squamation, and the general appearance, agree well with those of the new species. Another possibility is that his specimen was a representative of
N. proxima
(Smith & Radcliffe
in
Radcliffe, 1912
), a moderately common species at upper and mid-slope depths in the Pacific off southern
Japan
. Although Kamohara extensively surveyed the deep demersal fishes of Tosa Bay and adjacent waters, he did not record
N. proxima
during his career.
Nezumia burragei
appears to be confined to the Hawaiian Archipelago, and is unlikely to occur in Japanese waters. Therefore, this species is excluded from the list of Japanese grenadiers in this study.