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
Genus
Epigonus
Rafinesque, 1810
Diagnosis
(based on
Western
Indian Ocean species).
A genus of the family
Epigonidae
with the following combination of characters: body elongate, body depth 16–27% SL; first dorsal-fin spines 7–8 (the
8th may
present as an isolated spine between first dorsal and second dorsal fins); second dorsal-fin with a single spine and soft rays 9–11; anal fin with 2 spines and 8–9 soft rays; pectoral-fin rays 15–23; gill rakers 18–36; lateral-line scales 33–51; pyloric caeca 5–35; infraorbital bones 8, smooth; branchiostegal rays 7; edges of opercular bones smooth to weakly serrated; lateral line scales on caudal peduncle not forming a keel; no antrorse teeth in upper jaw; procurrent rays soft.
Remarks.
The epigonid genera,
Epigonus
,
Brephostoma
Alcock, 1889
,
Florenciella
Mead & De Falla, 1965
,
Rosenblattia
Mead & De Falla, 1965
and
Sphyraenops
Poey, 1861
, are distributed in the
Western
Indian Ocean and closely related to each other.
Epigonus
differs from
Brephostoma
in having 7–8 first dorsal-fin spines and 2 anal-fin spines (vs. 6 first dorsal fin spines and one anal fin spine in
Brephostoma
). Also,
Epigonus
differs from
Florenciella
and
Rosenblattia
in having 9–11 soft rays in the second dorsal fin (vs.
7–8 in
the latter two genera), a shallower body depth [16–27 % SL vs. 25–42 % SL from
Mead & De Falla (1965)
], soft procurrent rays (vs. stiff), and in lacking antrorse teeth on the upper jaw (vs. present on the both jaws).
Epigonus
can be distinguished from
Sphyraenops
by having none or a single pungent opercular spine (vs. 3 opercular spines in
Sphyraenops
), 2 spines and 8–9 soft rays on the anal fin (vs. 3 spines and 7 soft rays on the anal fin), and 7 branchiostegal rays (vs. 6 branchiostegal rays). The genus
Epigonus
of the
Western
Indian Ocean are represented by 14 species, including two new species here described (
Figs. 1–3
).