A review of the deepwater cardinalfish genus Epigonus (Perciformes: Epigonidae) of the Western Indian Ocean, with description of two new species
Author
Okamoto, Makoto
Author
Gon, Ofer
text
Zootaxa
2018
2018-02-21
4382
2
261
291
journal article
30691
10.11646/zootaxa.4382.2.3
6dc55986-74fa-4ac0-bca6-b301f3831180
1175-5326
1182167
8E248E6F-FDA5-4829-9DD7-4CC0EFDB08B6
Epigonus lenimen
(Whitley, 1935)
(English name: Bigeye Deepsea Cardinalfish) (
Figs. 3
,
12
; Tables 1, 2)
Scepterias lenimen
Whitley, 1935: 230
(in part, original description; type locality: Great Australian Bight; holotype: AMS E.3368); Whitley, 1940: 420, fig. 33 (list and figure, Australia); Whitley, 1968: 56 (in part, list, New Zealand).
Epigonus lenimen
Scott, 1962: 191
, fig. 1 (Australia);
Mayer, 1974
: 193
, fig. 22 (description, Australia and New Zealand); Parin & Abramov, 1986b: 187 (description, New Zealand);
Mochizuki, 1990
: 259
(description, New Zealand);
Allen & Cross, 1989
: 553
(list, Australia); Paulin
et al
., 1989: 180 (key, New Zealand);
Abramov, 1992
: 100
(key);
Gomon
et al
., 1994
: 563
(brief description and photograph, Australia);
Hutchins, 2001
: 32
(list, Western Australia);
Hoese
et al
., 2006
: 1114
(list, Australia);
Okamoto & Fukui, 2011
: 391
(key); Okamoto, 2012: 252 (key); Stewart & Gon, 2015: 1222 (key and description, New Zealand).
Material examined.
MNHN 1989-1121
,
2 specimens
,
107.7–108.6 mm
SL,
38°48.0 S
,
77°34.1 E
, off
Saint-Paul
,
South
Indian Ocean,
350–412 m
depth,
18 July 1986
;
SAIAB 82133
, 105.0 mm SL,
21°36.1 S
,
35°42.1 E
, off
Mozambique
,
599–601 m
,
17 October 2007
.
Diagnosis.
Dorsal-fin rays VII-I, 9; pectoral-fin rays 16–18; total gill rakers 28–33; vertebrae 11 + 14; pyloric caeca 6–9; pored lateral-line scales 46–49 + 3–5; scales below lateral line 9–10; pungent opercular spine present; blunt maxillary mustache-like processes present; ribs on last abdominal vertebra present; tongue toothless; no tubercle or two nub-like structures on symphysis of lower jaw; body depth 23.8–28.1% SL; orbital diameter 14.1– 17.7 % SL; lower-jaw length 14.9–16.4% SL.
Measurements (% SL)
; counts are given in Table 1. Head length 34.6–36.0; head width 16.9–18.6; head height 16.9–18.2; body depth 23.8–24.3; body width 14.2–15.2; caudal-peduncle depth 9.4–10.3; caudal-peduncle length 25.8–28.1; orbital diameter 15.7–16.4; interorbital width 9.7–9.8; postorbital length 10.2–13.3; upper-jaw length 15.2–15.4; lower-jaw length 15.7–16.2; snout length 7.2–8.3; pre-first dorsal-fin length 36.9–38.9; presecond dorsal-fin length 57.8–58.8; pre-pectoral-fin length 34.1–34.5; pre-pelvic-fin length 38.8–39.0; pre-anus length 59.1–59.6; pre-anal-fin length 66.3–66.8; first spine length on first dorsal fin 3.1; second spine length on first dorsal fin 16.1–17.4; third spine length on first dorsal fin 16.6–18.1; second dorsal-fin spine length 16.7–17.7; first anal-fin spine length 4.4–5.0; second anal-fin spine length 19.3–19.7; pelvic-fin spine length 17.6–17.7; first dorsal-fin base length 11.9–13.5; second dorsal-fin base length 10.5–11.8; anal-fin base length 9.8–12.1; pectoralfin length 20.5–20.9; pelvic-fin length 20.7–22.2.
Distribution.
Western
South
Indian Ocean (Parin & Abramov 1986b;
Abramov 1992
);
New Zealand
(
Mayer 1974
; Paulin
et al
. 1989;
Mochizuki 1990
; Stewart & Gon 2015); southern
Australia
(
Mayer 1974
;
Hutchins 2001
;
Hoese
et al
. 2006
), at
300–1050 m
depth.
Comparisons and Remarks
.
Epigonus lenimen
belongs to the
E. constanciae
group by having a pungent opercular spine (Okamoto 2012). This species is similar to
E. robustus
in having 11 + 14 vertebrae; however, it differs from
E. robustus
in orbital diameter longer than postorbital length (
Fig. 12
) (vs. orbital diameter shorter than postorbital length in
E. robustus
) and in lacking two nub-like structures on the symphysis of lower jaw (vs. present in
E. robustus
). The other 5 species of the group in the
Western
Indian Ocean,
E. bispinosus
,
E. idai
,
E. marimonticolus
,
E. pectinifer
and
E. waltersensis
, have 10 + 15 vertebrae (vs. 11 +
14 in
E. lenimen
).
Epigonus lenimen
is originally described based on
holotype
and nine
paratypes
from
Australia
(Whitley 1935).
According to a re-examination of Whitley’s
type
series by
Mayer (1974)
, the
paratypes
were identified as
E. denticulatus
in his revision of the genus.