Revision of the circumglobal deep-sea genus Leucicorus (Teleostei, Ophidiidae) with two new species
Author
Schwarzhans, Werner W.
Zoological Museum, Natural History Museum of Denmark, Universitetsparken 15, 2100 Copenhagen Ø, Denmark and Ahrensburger Weg 103, 22359 Hamburg, Germany
Author
Nielsen, Jørgen G.
Zoological Museum, Natural History Museum of Denmark, Universitetsparken 15, 2100 Copenhagen Ø, Denmark. jgnielsen @ snm. ku. dk
Author
Mundy, Bruce C.
Ocean Research Explorations, P. O. Box 235926, Honolulu, HI 96823, USA. mundyichthyo @ gmail. com
text
Zootaxa
2022
2022-02-22
5100
4
541
558
journal article
20509
10.11646/zootaxa.5100.4.5
88055c49-f6af-41f7-9672-96d9572b7639
1175-5326
6224876
8DD15BEE-86E0-4DD8-AC05-6C76A993508C
Leucicorus lusciosus
Garman, 1899
Table 1
,
Figs. 1D–E
,
2A
,
3J–K
,
5
Leucicorus lusciosus
Garman, 1899: 146
.
Leucicorus lusciosus
:
Grey 1956: 218
;
Nielsen 1975: 109
.
Material examined
(
2 specimens
, SL
225–245 mm
and a radiograph of
SIO 81–148
)
.
Holotype
:
MCZ
28680
, 245 mm SL, male, eastern tropical
Pacific
,
14
°
46’N
,
98°40’W
,
R
/
V
Albatross
, st. 3415, beam trawl,
3436 m
,
10 Apr. 1891
.
Non-types
:
ZMUC
P
771814, 225 mm
SL, female, off
Peru
,
17°42’S
,
78°59’W
,
R
/
V
Akademik Kurchatov
, st. 271,
Sigsbee
trawl,
2710–3080 m
,
20 Dec. 1968
.
Radiograph
and otolith of
SIO 81–148
,
251
+ mm SL, female,
Panama
Basin
,
5.175°N
,
81°68’W
,
R
/
V
Melville
, 40’ otter trawl, PA 3,
3900–4000 m
,
31 Mar. 1931
.
Diagnosis.
Dorsal-fin rays 110–114 and anal-fin rays 87–99; total vertebrae 68–69. Extensive squamation on opercle, preopercle and occiput; 35 to 40 transversal scale rows on trunk above beginning of anal fin. Otolith elongate (OL:OH = 1.65–1.75), with inner face more strongly convex than outer face.
Comparison.
L. lusciosus
is most similar to
L. gerringerae
, due to the extensive squamation on head; however, it differs from
L. gerringerae
by having more dorsal- (110–114
vs.
97) and anal-fin (96–99
vs.
73–80) rays, smaller scales on head (~
1 mm
vs 2.0–
2.5 mm
) and more scale rows on trunk above anal-fin origin (35–40
vs.
24–25). It differs from both
L. atlanticus
and
L. lentibus
by the extensive head squamation and a high number of transversal scale rows above origin of anal fin.
Description.
The principal meristic and morphometric characters are shown in
Table 1
. Body elongate and compressed with tapering tail; head broad with dorsal profile straight except for a slight concavity above eyes; head bones thin and fragile. Anterior nostril placed midway between upper lip and posterior nostril and the larger posterior nostril close to orbit. Orbit equal in length of snout; lens poorly developed or absent. Opercular spine thin and pointed. Body fully scaled, head with scales on opercle, preopercle and occiput. Pelvic fins each with two tightly joined rays. Pectoral fins placed on midbody. Mouth terminal; upper jaw ends below posterior edge of orbit; supramaxilla well developed. Anterior gill arch with 9–10 long developed and eight knob-like rakers. 1–2 pseudobranchial filaments.
Otolith (
Fig 3J–K
). Large otoliths up to
11.4 mm
in length with slender, droplet-like shape (OL:OH = 1.65– 1.75). Ventral rim shallow; dorsal rim higher, broadly rounded, with obtuse pre- to mediodorsal angle; anterior rim broadly rounded; posterior tip slightly tapering. Inner face convex, outer face flat to slightly convex; otolith height: thickness = 2.0–2.6. Sulcus straight, shallow, narrow, with single well-defined colliculum; otolith length: sulcus length = 1.80–1.9; sulcus length: height = 3.6–4.3. Sulcus not connected to anterior-dorsal rim. Ventral furrow well expressed, close to ventral otolith rim; indistinct dorsal depression.
Distribution
(
Fig. 5
). Known from three localities in the East Pacific Ocean. Caught in bottom trawls at 2710– 4000 meters.
Leucicorus lusciosus
is the only species in the genus caught at bathyal depth. Two sightings by ROV from the NOAA ship
Okeanos Explorer
campaign south of
Hawaii
and near the southern
Line Islands
may also belong to
L. lusciosus
(see below).