Two new species of the deepwater cardinalfish genus Epigonus (Epigonidae) from deep reefs off Curaçao, southern Caribbean

Abstract

Two new species of deepwater cardinalfish, Epigonus gemma [7 specimens, 37.7–76.7 mm in standard length (SL)] and Epigonus hexacanthus (22 specimens, 32.2–57.0 mm SL) are described based on specimens from deep reefs off Curaçao, southern Caribbean Sea. Epigonus gemma is distinguished from other congeners by a combination of the following characters: dorsal-fin rays VII-I, 9–10; pectoral-fin rays 16; total gill rakers 25–27; vertebrae 10 + 15; pyloric caeca 8–9; pored lateral-line scales 43–44 + 5–6; opercular spine absent; maxillary mustache-like processes absent; ribs on last abdominal vertebra absent; tongue toothless; endopterygoid teeth absent; and enlarged conical teeth on symphysis of lower jaw present. Epigonus hexacanthus is distinguished from other congeners by a combination of the following characters: dorsal-fin rays VI-I, 10; pectoral-fin rays 16–17; total gill rakers 25–27; vertebrae 10 + 15; pyloric caeca 6–7; pored lateral-line scales 32–35 + 3–5; opercular spine absent; maxillary mustache-like processes absent; ribs on last abdominal vertebra absent; lingual teeth present; endopterygoid teeth present; and enlarged conical teeth on symphysis of lower jaw absent. Eight specimens (37.6–54.4 mm SL) of E. hexacanthus are female with mature gonads, rendering the species the smallest in size at sexual maturity among its congeners. A key to the species of Epigonus currently known from the Caribbean Sea is provided.

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Vol.:(0123456789)
Ichthyological Research
https://doi.org/10.1007/s10228-024-00948-2
FULL PAPER
Two new species ofthedeepwater cardinalfish genus Epigonus
(Epigonidae) fromdeep reefs offCuraçao, southern Caribbean
MakotoOkamoto1 · CaroleC.Baldwin2· DouglasJ.Long3
Received: 20 September 2023 / Revised: 24 December 2023 / Accepted: 9 January 2024
© The Author(s) under exclusive licence to The Ichthyological Society of Japan 2024
Abstract
Two new species of deepwater cardinalfish, Epigonus gemma [7 specimens, 37.7–76.7 mm in standard length (SL)] and
Epigonus hexacanthus (22 specimens, 32.2–57.0mm SL) are described based on specimens from deep reefs off Curaçao,
southern Caribbean Sea. Epigonus gemma is distinguished from other congeners by a combination of the following char-
acters: dorsal-fin rays VII-I, 9–10; pectoral-fin rays 16; total gill rakers 25–27; vertebrae 10 + 15; pyloric caeca 8–9; pored
lateral-line scales 43–44 + 5–6; opercular spine absent; maxillary mustache-like processes absent; ribs on last abdominal
vertebra absent; tongue toothless; endopterygoid teeth absent; and enlarged conical teeth on symphysis of lower jaw pre-
sent. Epigonus hexacanthus is distinguished from other congeners by a combination of the following characters: dorsal-fin
rays VI-I, 10; pectoral-fin rays 16–17; total gill rakers 25–27; vertebrae 10 + 15; pyloric caeca 6–7; pored lateral-line scales
32–35 + 3–5; opercular spine absent; maxillary mustache-like processes absent; ribs on last abdominal vertebra absent; lingual
teeth present; endopterygoid teeth present; and enlarged conical teeth on symphysis of lower jaw absent. Eight specimens
(37.6–54.4mm SL) of E. hexacanthus are female with mature gonads, rendering the species the smallest in size at sexual
maturity among its congeners. A key to the species of Epigonus currently known from the Caribbean Sea is provided.
Keywords Submersible· COI· Curaçao· Deep Reef Observation Project (DROP)
Introduction
The deepwater cardinalfish genus Epigonus Rafinesque
1810 is the most species-rich and widely distributed genus
in the family Epigonidae, with 40 valid species (Mayer 1974;
Abramov 1992; Okamoto and Miyamoto 2022). In several
taxonomic studies of Epigonus, the first author proposed
four species groups (Okamoto 2011, 2012; Okamoto and
Motomura 2011, 2013): the Epigonus constanciae group, the
Epigonus oligolepis group, the Epigonus pandionis group,
and the Epigonus telescopus group. Recent taxonomic stud-
ies of the genus have focused on the Indo-Pacific region
(Okamoto 2018; Okamoto and Gon 2018; Okamoto etal.
2020; Okamoto and Miyamoto 2022), and study in the west-
ern Atlantic Ocean has not progressed since Mayer (1974).
Previous submersible diving off Curaçao in the southern
Caribbean as part of the Smithsonian’s Deep Reef Observa-
tion Project (DROP) collected two species of Epigonus that
are morphologically distinct from currently known species.
These species are described herein, and a key to the species
in the Caribbean Sea is provided.
Materials andmethods
Specimens were collected on dives made in 2012–2014
in the human-occupied submersible Curasub (http:// www.
subst ation- Curac ao. com). Fish specimens were collected
This article was registered in the Official Register of Zoological
Nomenclature (ZooBank) as 440A7 C80- 84A3- 490D- A33A- 27B6E
B7D79 CF.
This article was published as an Online First article on the online
publication date shown on this page. The article should be cited by
using the doi number.
* Makoto Okamoto
epigonidae@gmail.com
1 Marine Fisheries Research andDevelopment Center, Japan
Fisheries Research andEducation Agency, 6F Techno Wave
100, 1-1-25 Shin-urashima-cho, Kanagawa-ku, Yokohama,
Kanagawa221-5829, Japan
2 Department ofVertebrae Zoology, National Museum
ofNatural History, Smithsonian Institution, 20560,
WashingtonD.C., USA
3 Department ofIchthyology, California Academy ofSciences,
55 Music Concourse Dr., SanFrancisco, CA94118, USA

M. Okamoto etal.
using the fish anesthetic quinaldine pumped from a reser-
voir through a tube attached to one hydraulic arm of the
sub and a suction hose attached to the other arm. The hose
empties into a vented plexiglass cylinder attached to the
outside of the sub. At the surface, some specimens were
measured, photographed, tissue sampled (muscle biopsy
from right side) and preserved.
Meristic and morphometric methods followed Mayer
(1974) and Okamoto (2011). Missing lateral-line scales
were estimated by counting scale pockets. The number of
pored lateral-line scales on the caudal fin is represented
as “+ n”. The first caudal vertebra is defined as the first
vertebra bearing a definite hemal spine. Measurements
were made with calipers to the nearest 0.1 mm. Terminol-
ogy and formula of the supraneural bones follows Mabee
(1988) and Ahlstrom etal. (1976), respectively. Counts of
supraneurals, vertebrae, and ribs were taken from radio-
graphs. The term “maxillary mustache-like process” is
used for a process on the maxillary head (see Okamoto
2011: fig.3). The number of pyloric caeca and sex were
established by dissection of the abdomen on the right side.
Standard length is abbreviated as SL. Institutional codes
follow Sabaj (2020).
Tissue samples for DNA Barcoding were stored in satu-
rated salt-DMSO (dimethyl sulfoxide) buffer (Seutin etal.
1991). DNA extraction, PCR, sequencing cytochrome c oxi-
dase subunit I (COI), and editing COI sequences were per-
formed as outlined by Weigt etal. (2012). Sequences were
uploaded to the Barcode of Life Database (Bin Numbers
BOLD: ACG7476 and BOLD: ACG7477, boldsystems.org)
and Genbank (Accession numbers OR918549–OR918570),
and sequences of the holotypes of the two species were
entered into the BOLD search engine for comparison with
other available sequences of Epigonus.
Epigonus gemma sp. nov.
(Figs.1, 2)
Holotype. USNM 431654, 76.7 mm SL, male, DNA
#CUR14082, Curasub submersible, sta. 14-12, Curaçao, east
of downline at Substation Curaçao, 12°05.00′N, 68°53.57′W,
275m depth, 16 September 2014, C. Baldwin, L. Weigt, B.
Van Bebber, R. Betancur.
Paratypes. 6 specimens: USNM 413854, 71.5mm SL,
male, DNA #CUR12009, Curasub submersible, sta. 12-01,
Fig. 1 Epigonus gemma sp.
nov. a USNM 431654, holo-
type, 76.7mm SL, preserved
specimen; b USNM 413854,
paratype, 71.5mm SL, fresh
specimen (photographed by C.
C. Baldwin); c USNM 413858,
paratype, 62.6mm SL, radio-
graph

Two new epigonids from Curaçao
Curaçao, off Substation Curaçao downline, 12°04.59′N,
68°53.56′W, 171–309 m depth, 21 May 2012, C. Bald-
win, A. Schrier, B. Brandt; USNM 413858, 62.6mm SL,
male, DNA #CUR12088, USNM 413859, 54.7mm SL,
sex unknown, DNA #CUR12089, USNM 413861, sex
unknown, DNA #CUR12091, Curasub submersible, sta.
12-12, Curaçao, east of downline at Substation Curaçao,
12°04.59′N, 68°53.56′W, 156–290 m depth, 7 August
2012, C. Baldwin, A. Schrier, D. Pawson; USNM 413862,
53.5mm SL, sex unknown, DNA #CUR12296, Curasub
submersible, sta. 12-18, Curaçao, off Substation Curaçao
downline, 12°04.59′N, 68°53.56′W, 291–294m depth, 14
August 2012, A. Schrier, B. Brandt, C. Baldwin, A. Driskell;
USNM 431690, 76.1mm SL, male, DNA #CUR14082,
Curasub submersible, sta. 14-09, Curaçao, east of downline
at Substation Curaçao, 12°04.59′N, 68°53.56′W, 265–293m
depth, 24 June 2014, C. Baldwin, B. Brandt, A. Schrier.
Diagnosis. A species of Epigonus with the following
combination of characters: dorsal-fin rays VII-I, 9–10; pec-
toral-fin rays 16; total gill rakers 25–27; vertebrae 10 + 15;
pyloric caeca 8–9; pored lateral-line scales 43–44 + 5–6;
opercular spine absent; maxillary mustache-like processes
absent; ribs on last abdominal vertebra absent; tongue tooth-
less; endopterygoid teeth absent; enlarged conical teeth on
symphysis of lower jaw present.
The DNA barcode for the holotype (USNM 431654) is as
follow s: NNNNNNNNNNNNNNNNNNNNNNNCCT TTA
TCT CGT ATT TGG TGC TTG AGC CGG AAT AGT GGG CAC
AGC CTT AAG CCT GCT TAT TCG GGC AGA ACT CAG CCA
ACC AGG CGC CCT CCT CGG AGA CGA CCA GAT CTA TAA
CGT AAT TGT TAC AGC ACA CGC CTT CGT AAT AAT TTT
CTT TAT AGT AAT ACC AAT TAT GAT TGG GGG CTT CGG
AAA TTG GCT TAT CCC TTT AAT AAT TGG GGC CCC TGA
TAT AGC CTT CCC TCG AAT AAA TAA TAT AAG CTT TTG
ACT CCT CCC TCC TTC CTT CCT GCT CCT TCT TGC CTC
TTC TGG GGT AGA AGC CGG TGC CGG CAC CGG CTG
AAC AG T TTA CCC CCC TCT GGC TGG GAA CTT AGC CCA
CGC GGG GGC CTC TGT TGA TTT AAC AAT CTT TTC TCT
ACA TCT TGC AGG TAT TTC CTC AAT TCT TGG GGC TAT
TAA CTT TAT TAC AAC AAT TAT TAA TAT AAA ACC CCC
GGC CAT TT C ACA ATA CCA AAC ACC CCT GTT TGT GTG
AGC AGT ATT AAT TAC CGC AGT TCT TCT TCT GCT GTC
CCT CCC TGT CCT TGC TGC TGG AAT TAC AAT GCT TCT
TA C AGA CCG AAA CCT CAA CAC CAC CTT CTT TGA CCC
GGC AGG AGG AGG GGA CCC CAT CCT CTA CCA ACA
CCT GTT TNNNNNNNNNN.
Description. Counts and proportional measurements are
given in Table1. Data for the holotype are presented first,
followed by data of paratypes (if different) in parentheses.
Body moderately slender, laterally compressed, nape slightly
humped, deepest at pectoral-fin base (Fig.1). Head large,
laterally compressed. Maxillary mustache-like process
absent. Snout short and round; two nostrils close-set with-
out dermal flap, anterior nostril short and with membranous
tube, posterior nostril elliptical. Eye large, round, diameter
slightly shorter than postorbital length (subequal); bony
rim of orbit slightly raised above dorsal profile; interorbital
region flat. Mouth large, terminal, gape oblique; posterior
margin of maxilla extending to below anterior margin of
pupil; lower jaw slightly projecting when mouth closed;
nob-like structures absent on symphysis of lower jaw. Upper
jaw teeth small conical, arranged in a single series visible
when mouth closed. Lower jaw teeth small conical, arranged
in a single series; tip of lower jaw curved slightly upward,
symphysis forming a thick bony projection, three enlarged
conical teeth on each side of symphysis of lower jaw (one
to three enlarged conical teeth on each side of symphysis of
lower jaw; Fig.2). Small number of villiform teeth present
on vomer. Single row of small conical teeth (rarely two rows)
on palatines. Tongue and endopterygoid toothless. Opercular
spine absent; preopercle without spines, ventral and poste-
rior margins smooth. Origin of first-dorsal fin located behind
base of pelvic fin; first dorsal-fin spine minute; fourth dorsal-
fin spine the longest, length longer than orbital diameter;
two supernumerary spines on first dorsal pterygiophore.
Spine of second dorsal fin long. First and second dorsal fins
separated by gap longer than snout length. Origin of anal
fin vertically below 4th soft ray of second dorsal-fin; first
anal-fin spine minute; second spine long, length longer than
orbital diameter; two supernumerary spines on first anal
Fig. 2 Lateral view of mouth of Epigonus gemma sp. nov., USNM
413854, paratype, 71.5mm SL. Arrow shows enlarged conical teeth
on symphysis of lower jaw

M. Okamoto etal.
Table 1 Counts and measurements of Epigonus gemma sp. nov. and Epigonus hexacanthus sp. nov.
Epigonus gemma Epigonus hexacanthus
Holotype
USNM 431654
Paratypes (n = 6) Holotype
USNM 422678
Paratypes (n = 11)
Standard length (mm) 76.7 37.7–76.1 54.4 33.0–56.3
Counts
Dorsal-fin rays VII-I, 10 VII-I, 9–10 VI-I, 10 VI-I, 10
Anal-fin rays II, 9 II, 9 II, 9 II, 9
Pectoral-fin rays 16 16 16 16–17
Pored lateral-line scales 43 + 5 43–44 + 5–6 34 + 5 32–35 + 3–5
Scales above lateral line 2 2 2 2
Scales below lateral line 9 8–9 7 7
Gill rakers 7 + 19 = 26 6–7 + 19–20 = 25–27 6 + 20 = 26 6 + 19–21 = 25–27
Pyloric caeca 8 9 7 6–7
Vertebrae 10 + 15 10 + 15 10 + 15 10 + 15
Measurements (% standard length)
Head length 32.7 31.0–34.6 33.8 33.6–39.4
Head width 14.9 11.1–14.8 14.2 13.4–17.6
Head height 16.2 14.8–17.3 14.7 13.0–17.6
Body depth 22.8 21.4–25.0 19.3 18.6–21.9
Body width 13.8 9.3–14.1 12.5 11.4–14.7
Caudal-peduncle depth 10.3 8.6–10.6 8.8 8.1–9.8
Caudal-peduncle length 29.6 26.7–29.6 27.4 26.9–30.7
Orbital diameter 12.3 12.0–12.7 12.3 11.8–14.5
Interorbital width 7.6 6.4–7.3 8.1 7.8–9.8
Postorbital length 12.5 10.8–13.9 12.7 10.7–14.2
Upper-jaw length 14.1 12.6–14.9 15.1 14.5–16.8
Lower-jaw length 15.3 14.1–17.2 15.6 15.5–18.2
Snout length 6.9 6.8–9.0 9.2 8.2–9.9
Pre-1st dorsal-fin length 37.3 35.8–41.1 39.0 35.9–43.3
Pre-2nd dorsal-fin length 57.6 56.1–60.4 54.2 53.3–61.7
Pre-pectoral-fin length 32.1 31.7–36.9 33.8 34.3–39.3
Pre-pelvic-fin length 35.6 35.5–39.5 36.8 36.9–41.2
Pre-anus length 57.2 54.3–60.7 55.5 54.2–64.5
Pre-anal-fin length 64.5 61.7–66.5 62.9 59.9–68.1
1st spine length on 1st dorsal-fin 2.9 2.6–3.5 9.6 9.4–13.1
2nd spine length on 1st dorsal-fin 15.5 12.5–15.1 10.1 11.9–15.9
3rd spine length on 1st dorsal-fin 16.4 14.3–16.3 11.6 12.6–15.6
2nd dorsal-fin spine length 14.1 11.4–13.5 8.8 8.9–13.9
1st anal-fin spine length 2.0 1.5–2.2 1.5 1.2–1.9
2nd anal-fin spine length 15.1 10.6–14.5 7.4 7.8–11.3
Pelvic-fin spine length 14.9 11.4–15.4 9.0 8.2–11.5
1st dorsal-fin base 11.6 10.8–12.6 10.5 8.9–11.4
2nd dorsal-fin base 10.6 10.5–12.8 9.9 9.1–10.6
Anal-fin base 10.0 9.3–11.3 8.8 8.2–9.6
Pectoral-fin length 18.1 17.2–20.7 19.9 19.0–23.4
Pelvic-fin length 21.5 17.7–21.7 14.3 14.7–18.0

Two new epigonids from Curaçao
pterygiophore. Pectoral fin short, posterior tip of fin not
reaching to vertical line from anus. Pelvic fin long, poste-
rior tip just before to anus. Caudal fin deeply forked. Anus
located vertically below origin of second dorsal-fin base.
Ribs absent on last abdominal vertebra (Fig.1c). Supraneu-
ral bones 3 (/0+0/0+2/1+1/1/). Scales deciduous, small,
weakly ctenoid, covering the whole body except snout tip,
anterior to rim of orbit, and surface of jaws; scales also pre-
sent on bases of second dorsal, anal and caudal fins; series
of pored lateral-line scales complete, 5 (5–6) pored scales
on caudal fin. No trace of luminous organ around belly or
pyloric caeca.
Color when fresh (Fig.1b). Dorsal portions of body and
head light purple; ventral surface and lower half of body
silvery-tan. All fins light black. Gill cover light blue, poste-
rior margin black.
Color in alcohol (Fig.1a). Body and head uniformly light
brown, except for the snout and gill cover which are dark
gray. Dorsal, anal, pelvic, and caudal fins dark gray, with
many melanophores on the soft rays and membranes. Pec-
toral fin light gray except for dark base. Mouth cavity tan.
Distribution. Known only from Curaçao, southern
Caribbean.
Habitat. Epigonids are common at Curaçao at depths
near the lower limit of the Curasub (300m), especially in
caves and crevices along a near-vertical rock wall [Electronic
Supplementary Material (ESM) Video S1]. All specimens
described in this study, including those of E. gemma sp. nov.,
were collected in this habitat.
Etymology. The specific name gemma is from the Latin
meaning bud, in reference to the enlarged conical teeth on
each side of the symphysis of the lower jaw (Fig.2).
Comparison. Epigonus gemma sp. nov. belongs to a
group of similar species in the E. pandionis group (Oka-
moto and Motomura 2013). The E. pandionis group is distin-
guished from the other three species groups of the genus (the
E. constanciae group, E. oligolepis group, and E. telescopus
group) in having more than 43 pored lateral-line scales, lack-
ing an opercular spine, and having VII-I, 9–11 dorsal-fin
rays (Okamoto and Motomura 2013). Okamoto and Moto-
mura (2013) indicated that the E. pandionis group comprises
nine species, viz., Epigonus cavaticus Ida etal. 2007; Epigo-
nus denticulatus Dieuzeide 1950; Epigonus elongatus Parin
and Abramov 1986; Epigonus fragilis (Jordan and Jordan
1922); Epigonus lifouensis Okamoto and Motomura 2013;
Epigonus marisrubri Krupp etal. 2009; Epigonus pandionis
(Goode and Bean 1881); Epigonus parini Abramov 1987;
and Epigonus tuberculatus Okamoto and Motomura 2013.
Epigonus gemma sp. nov. is unique in the group in hav-
ing enlarged conical teeth on each side of the symphysis of
lower jaw (vs. absent).
In addition, E. gemma sp. nov. can be distinguished from
E. denticulatus, E. elongatus, E. lifouensis, E. marisrubri,
E. pandionis, E. parini, and E. tuberculatus by having 16
pectoral-fin rays and 25–27 gill rakers (vs. 18–21 and 28–34,
respectively in E. denticulatus; 18–20 and 28–34 in E. elon-
gatus; 18–19 and 24–25 in E. lifouensis; 17–18 and 29–30
in E. marisrubri; 17–19 and 26–30 in E. pandionis; 18–20
and 35–39 in E. parini; and 19–20 and 21–22 in E. tuber-
culatus; Okamoto and Motomura 2013, table2). Epigonus
cavaticus and E. fragilis are similar to E. gemma sp. nov. in
having overlapping pectoral-fin rays and gill rakers but differ
from E. gemma sp. nov. in having a large number of pored
lateral-line scales (48–50 in E. cavaticus and 46–49 in E.
fragilis vs. 43–44 in E. gemma sp. nov.) and a pair of ribs on
the last abdominal vertebra (vs. absent in E. gemma sp. nov.;
Fig.1c). Epigonus gemma sp. nov. is distinguished from the
second new species in the present study, Epigonus hexacan-
thus sp. nov., in having enlarged conical teeth on symphysis
of lower jaw (vs. absent in E. hexacanthus), 7 spines on the
first dorsal-fin (vs. 6 spines), and 43–44 lateral-line scales
(vs. 32–35 lateral-line scales).
Remarks. Within Epigonus, only Epigonus exodon Oka-
moto and Motomura 2012 and Epigonus glossodontus Gon
1985 have the enlarged conical teeth on each side of the
lower-jaw symphysis present in E. gemma (Okamoto and
Gon 2018; Okamoto etal. 2020). Epigonus exodon has been
reported to undergo growth changes in those teeth (Okamoto
and Motomura 2012), but no growth changes in those teeth
were found in E. gemma sp. nov. between 37.3 mm SL and
76.7mm SL.
The holotype and seven paratypes of E. gemma sp. nov.
are males of 62.6–76.7mm SL with a large testis. The sex
of the remaining type specimens was unknown. Although no
mature eggs were found, the present species is most likely
a small species.
The DNA barcode of the holotype, USNM 431654, clus-
ters in BOLD with six other sequences of E. gemma sp. nov.
from Curaçao (USNM 413854, 413858, 413859, 413861,
413862, 431690). That lineage is approximately 5% diver-
gent from “Epigonus sp.” from India (accession number:
GBMND26919-21, GBMND26920-21, and GBMND26921-
21) and 11% divergent from Epigonus hexacanthus sp. nov.
From other species of Epigonus known from the Caribbean
Sea that are represented in the BOLD database [E. denticu-
latus, Epigonus macrops (Brauer 1906), E. pandionis], the
barcode of E. gemma differs by more than 17%. Intraspecific
divergence in COI sequences for E. gemma is < 0.5%.
Epigonus hexacanthus sp. nov.
(Figs.3, 4)

M. Okamoto etal.
Holotype. USNM 422678, 54.4mm SL, female, DNA
#CUR13115, Curasub submersible, sta. 13-06, Curaçao, east
of downline at Substation Curaçao, 12°04.59′N, 68°53.56′W,
265m depth, 23 May 2013, D. Robertson, M. Harasewych,
C. Castillo, B. Brandt.
Paratypes. 11 specimens: USNM 413950, 44.1mm
SL, female, DNA # CUR13064, USNM 413951, 42.8mm
SL, male, Curasub submersible, sta. 13-01, Curaçao, off
Substation Curaçao downline, 12°04.59′N, 68°53.56′W,
52–304m depth, 5 February 2013, C. Baldwin, L. Weigt, L.
Fig. 3 Epigonus hexacanthus
sp. nov. a USNM 422678,
holotype, 54.4mm SL, pre-
served specimen; b USNM
413950, paratype, 44.1mm SL,
fresh specimen (photographed
by C. C. Baldwin); c USNM
431760, paratype, 56.3mm SL,
radiograph
Fig. 4 In situ image of Epigo-
nus hexacanthus sp. nov. taken
by the submersible Curasub on
23 May 2013, at 265m near the
bottom of rock wall at Curaçao
(photographed by C. C. Baldwin
and D. R. Robertson)

Two new epigonids from Curaçao
Wacchaus, B. Brandt, J. Piraino; USNM 426792, 33.3mm
SL, sex unknown, DNA #CUR13295, Curasub submers-
ible, sta. 13-21, Curaçao, off Substation Curaçao downline,
12°04.59′N, 68°53.56′W, 247m depth, 17 August 2013, C.
Baldwin, A. Schrier, B. Brandt, A. Driskell; USNM 431707,
50.1mm SL, female, DNA #CUR14099, Curasub submers-
ible, sta. 14-12, Curaçao, east of downline at Substation
Curaçao, 12°05.00′N, 68°53.57′W, 265m depth, 16 Septem-
ber 2014, C. Baldwin, L. Weigt, B. Van Bebber, R. Betan-
cur; USNM 431760, 7 specimens, 56.3mm SL, female,
47.4mm SL, female, 47.0mm SL, female, 44.0mm SL,
female, 37.6mm SL, female, 35.8mm SL, male, 32.3mm
SL, male, Curasub submersible, sta. 14-12, Curaçao, east of
downline at Substation Curaçao, 12°05.00′N, 68°53.57′W,
275m depth, 16 September 2014, C. Baldwin, L. Weigt, B.
Van Bebber, R. Betancur.
Non-type specimens. 10 specimens (all specimens were
subjected to DNA analysis). USNM 413848 (44.0mm
SL, DNA #CUR12003), USNM 413849 (46.0 mm
SL, DNA #CUR12004), USNM 413850 (49.0mm SL,
DNA #CUR12005), USNM 413851 (35.0 mm SL,
DNA #CUR12006), USNM 413852 (37.0 mm SL,
DNA #CUR12007), USNM 413853 (33.0 mm SL,
DNA #CUR12008), USNM 413855 (34.0 mm SL,
DNA #CUR12014), USNM 413857 (40.0mm SL, DNA
#CUR12016), Curasub submersible, sta. 12-01, Curaçao,
off Substation Curaçao downline, 12°04.59′N, 68°53.56′W,
171–309m depth, 21 May 2012, C. Baldwin, A. Schrier, B.
Brandt; USNM 413860, 50.0mm SL, DNA #CUR12090,
Curasub submersible, sta. 12-12, Curaçao, east of downline
at Substation Curaçao, 12°04.59′N, 68°53.56′W, 156–290m
depth, 7 August 2012, C. Baldwin, A. Schrier, D. Pawson;
USNM 431705, 57.0mm SL, DNA #CUR14097, Curasub
submersible, sta. 14-12, Curaçao, off Substation Curaçao
downline, 12°05.00′N, 68°53.57′W, 174–297m depth, 16
September 2014, C. Baldwin, L. Weigt, B. Van Bebber, R.
Betancur.
Diagnosis. A species of Epigonus with the following
combination of characters: dorsal-fin rays VI-I, 10; pectoral-
fin rays 16–17; total gill rakers 25–27; vertebrae 10 + 15;
pyloric caeca 6–7; pored lateral-line scales 32–35 + 3–5;
opercular spine absent; maxillary mustache-like processes
absent; ribs on last abdominal vertebra absent; lingual teeth
present; endopterygoid teeth present; enlarged conical teeth
on symphysis of lower jaw absent.
The DNA barcode for the holotype (USNM 422678) is as
follow s: NNNNNNNNNNNNNNNNNNNNNNNCCT CTA
TCT AGT ATT TGG TG C TT G AGC TGG AAT AGT AGG C AC
AGC CTT GAG T CT GCT TAT TCG GGC AG A ACT CAG CCA
ACC CGG CGC CCT CCT TGG AG A CGA CCA GAT CTA TAA
CGT AAT TGT TAC GGC GCA TGC TTT CGT AAT AAT TTT
CTT TAT AGT AAT ACC AAT CAT AAT TGG GGG TTT CGG
AAA TTG ACT TAT TCC CTT AAT AAT CGG GGC TCC TGA
TAT GGC CTT CCC TCG TAT AAA CAA CAT AAG CTT TTG
ACT CCT CCC TCC TTC CTT TCT ACT CCT CCT TGC CTC
TTC TGG GGT AGA AGC AGG AGC CGG CAC TGG GTG
AAC TGT CTA CCC CCC TTT AGC TGG TAA TCT CGC CCA
CGC GGG AGC CTC TGT TGA CTT AAC AAT CTT TTC CCT
ACA TTT AGC AGG TAT TTC CTC AAT TCT TGG GGC CAT
TAA CTT CAT TAC AAC AAT TAT TAA CAT AAA ACC TCC
TGC CAT CTC TCA ATA TCA AAC ACC TTT ATT TGT GTG
GGC AGT CTT AAT TAC AGC AGT CCT TCT TCT ACT TTC
TCT CCC CGT ACT TGC TGC TGG AAT TAC AAT GCT CCT
TA C GGA CCG AAA TCT TAA CAC CAC TTT CTT TGA CCC
AGC AGG GGG AGG GGA TCC CAT CCT TTA TCA AC A CCT
GTT TNNNNNNNNNN.
Description. Counts and proportional measurements
are given in Table1. Data for the holotype are presented
first, followed by data of paratypes (if different) in parenthe-
ses. Body slender, laterally compressed, nape not humped,
deepest at pectoral-fin base (Fig.3). Head large, laterally
compressed. Maxillary mustache-like process absent. Snout
short and round; two nostrils close-set without dermal flap,
anterior nostril short and with membranous tube, posterior
nostril elliptical. Eye large, round, diameter subequal to
postorbital length; bony rim of orbit slightly raised above
dorsal profile; interorbital region concave at center. Mouth
large, terminal, gape oblique; posterior margin of maxilla
extending to below anterior margin of pupil; lower jaw not
projecting when mouth closed; nob-like structures absent on
symphysis of lower jaw. Upper jaw teeth minute, arranged
in a single series, widely space. Lower jaw teeth minute,
arranged in a single series, except two rows at symphysis of
lower jaw, no enlarged teeth near symphysis. Vomerine teeth
minute, small number of teeth scattered on anterior part and
extending posteriorly along midline of palate. Palatine teeth
minute, single row. Endopterygoids bearing single row of
small conical teeth. Lingual teeth minute, arranged around
outer edge of tongue and two rows near center, not forming
dense tooth patch. Opercular spine absent; preopercle with-
out spines, ventral and posterior margins smooth. Origin of
first-dorsal fin located behind base of pelvic fin; first dor-
sal-fin spine long; third dorsal-fin spine the longest, length
shorter than orbital diameter; two supernumerary spines on
first dorsal pterygiophore. Spine of second dorsal fin long.
First and second dorsal fins separated by gap longer than
snout length. Origin of anal fin vertically below posterior
portion of second dorsal-fin base; first anal-fin spine minute;
second spine long, length shorter than orbital diameter; two
supernumerary spines on first anal pterygiophore. Pectoral
fin long, posterior tip of fin just reaching to vertical line from
anus. Pelvic fin short, posterior tip not reaching to anus.
Caudal fin deeply forked. Anus located vertically below ori-
gin of second dorsal-fin base. Ribs absent on last abdominal
vertebra (Fig.3c). Supraneural bones 3 (/0+0/0+1/1+1/1/).
Scales deciduous, large, weakly ctenoid, covering the whole

M. Okamoto etal.
body except snout tip, anterior to rim of orbit, and surface
of jaws; scales also present on bases of second dorsal, anal
and caudal fins; series of pored lateral-line scales complete,
5 (3–5) pored scales on caudal fin. No trace of luminous
organ around belly or pyloric caeca.
Color when fresh (Fig.3b). Dorsal portion of body and
head light gray; lower half of body silvery-white. Abdominal
cavity semitransparent with inner black peritoneum. Pecto-
ral, pelvic, and anal fins white. Dorsal and caudal fins light
black.
Color in alcohol (Fig.3a). Body and head uniformly light
brown, except for abdominal cavity and gill cover which
are beige. Pelvic fin white; pectoral, dorsal and caudal fins
light brown, with many melanophores on the soft rays and
membranes. Mouth cavity tan.
Distribution. Known only from Curaçao, southern
Caribbean.
Habitat. Epigonids are common at Curaçao at depths
near the lower limit of the Curasub (300m), especially in
caves and crevices along a near-vertical rock wall (Fig.4;
ESM Video S2). All specimens described in this study,
including those of E. hexacanthus, were collected in this
habitat.
Etymology. The specific name hexacanthus is derived
from the Greek hexa-(six) and acanthus (spine) in reference
to six spines on the first dorsal fin.
Comparison. Epigonus hexacanthus sp. nov. is unique
in the genus in having six spines in the first dorsal-fin (vs.
seven or eight spines in the first dorsal-fin; Okamoto and
Gon 2018). Abramov (1987) described E. parini as having
six spines in the first dorsal-fin, but Okamoto and Motomura
(2013) noted that this species clearly has seven.
Epigonus hexacanthus sp. nov. belongs to the E. oli-
golepis group defined by Okamoto and Motomura (2011).
The E. oligolepis group is distinguished from the other three
species groups of the genus (the E. constanciae group, E.
pandionis group, and E. telescopus group) in having 33–40
pored lateral-line scales (vs. 43–51 in the other three spe-
cies groups: Okamoto and Motomura 2011; Okamoto and
Gon 2018). Besides the present species, this species group
comprises 6 species: Epigonus carbonarius Okamoto and
Motomura 2011; Epigonus devaneyi Gon 1985; E. exodon;
E. glossodontus; Epigonus indicus Idrees Babu and Akh-
ilesh 2020; Epigonus oligolepis Mayer 1974. Epigonus
hexacanthus sp. nov. can be distinguished from E. devaneyi
and E. indicus by having lingual teeth (vs. absent; Okamoto
and Motomura 2011; Idrees Babu and Akhilesh 2020). The
present species also differs from E. carbonarius and E. oli-
golepis in having 25–27 gill rakers (vs. 21–23 in E. carbon-
arius and 29–32 in E. oligolepis). Epigonus hexacanthus sp.
nov. differs from E. exodon and E. glossodontus by lacking
enlarged conical teeth on the symphysis of lower jaw (vs.
present; Gon 1985; Okamoto etal. 2020).
Remarks. Most species of Epigonus were described
from adult specimens measuring 80–200mm SL (Okamoto
2011, 2012, 2015; Okamoto and Motomura 2011, 2013;
Okamoto and Gon 2018), and only Epigonus angustifrons
Abramov and Manilo 1987 and Epigonus telescopus (Risso
1810) exceed 300 mm SL (Abramov 1992; Okamoto and
Gon 2018). Ida etal. (2007) showed that E. cavaticus attains
sexual maturity at the smallest size among the congeners, as
females 63.7–66.8mm SL had mature gonads. In this study,
the holotype and seven paratypes of E. hexacanthus sp. nov.
are females of 37.6–54.4mm SL with a great number of
eggs at several developmental stages. The most developed
eggs were ca. 0.3mm in diameter and were round with a
single oil globule. Thus, E. hexacanthus sp. nov. seems to
attain sexual maturity at the smallest size among the species.
The DNA barcode of the holotype, USNM 422678,
clusters with 15 other sequences of E. hexacanthus from
Curaçao in BOLD (USNM 413705, 413707, 413848,
413849, 413850, 413851, 413852, 413853, 413855, 413857,
413860, 426792, 413950, 413951, 433523). That lineage is
approximately 11% divergent from E. gemma, 13% diver-
gent from “Epigonus sp.” from India (GBMND26919-21,
GBMND26920-21, and GBMND26921-21). From other
species of Epigonus known from the Caribbean Sea that
are represented in the BOLD database (E. denticulatus,
E. macrops, E. pandionis), the barcode of E. hexacanthus
differs by more than 19%. Intraspecific divergence in COI
sequences for E. hexacanthus is < 1%.
Epigonus indicus Idrees Babu and Akhilesh 2020, which
is in the same species group as E. hexacanthus sp. nov., was
described as having 10 + 14 vertebrae, a count they consid-
ered as an important diagnostic character for the species.
However, the radiograph in Idrees Babu and Akhilesh (2020,
fig.3) reveals a vertebral count of 10 + 15. Fishes of the
genus Epigonus have total of 25 vertebrae, with abdominal
and caudal vertebral counts of 10 + 15 or 11 + 14 (Mayer
1974; Okamoto and Gon 2018). Furthermore, Idrees Babu
and Akhilesh (2020) suggested the presence of a ventral
luminous organ based on a region of ventral fluorescent blue
color in E. indicus. However, this is the peritoneum, not a
ventral luminous organ. Among the species of the genus,
only E. macrops has a ventral luminous organ, formed by
a modification of one of eight pyloric caeca (Mayer 1974;
Okamoto etal. 2012; Okamoto and Gon 2018).
Key tospecies ofEpigonus oftheCaribbean
Sea
In the taxonomic study of Epigonus, Mayer (1974) reported
six species from the Caribbean Sea: E. denticulatus; E.
macrops; Epigonus occidentalis Goode and Bean 1896;
E. oligolepis; Epigonus pectinifer Mayer 1974; and E.

Two new epigonids from Curaçao
pandionis. Since then, Abramov (1992) and Gon (2003)
have reported on the distribution of species of Epigonus in
this area; however, no additional species have been found in
the area. We provide a key to the species from the Caribbean
Sea including the two species in this study.
1a. First dorsal-fin spines 6 ................... E. hexacanthus
1b. First dorsal-fin spines 7 ......................................... 2
2a. Pored lateral-line scales 33–36 ............ E. oligolepis
2b. Pored lateral-line scales more than 43 .................... 3
3a. Opercular spine present ......................................... 4
3b. Opercular spine absent .......................................... 5
4a. Tooth patch present on tongue; maxillary mustache-
like processes pointed; gill rakers 26–30 ... E. pectinifer
4b. Tongue toothless; maxillary mustache-like processes
absent; gill rakers 24–26 ........................ E. occidentalis
5a. Gill rakers 18–20; ventral luminous organ present
................................................................. E. macrops
5b. Gill rakers 25–34; ventral luminous organ absent ..... 6
6a. Enlarged teeth present on symphysis of lower jaw;
pyloric caeca 8–9; ribs absent on last abdominal vertebra
........................................................................ E. gemma
6b. Enlarged teeth absent on symphysis of lower jaw;
pyloric caeca 10–14; ribs present on last abdominal ver-
tebra ............................................................................. 7
7a. Body moderately deep, body depth 22.4–29.6%
SL; caudal-peduncle length 22.0–26.3% SL; gill rakers
26–30; 100–130mm SL specimens with posterodorsally
canted ring encircling the caudal peduncle (Mayer 1974;
Okamoto and Motomura 2013) .................. E. pandionis
7b. Body slender, body depth 15.8–23.6% SL; caudal-
peduncle length 25.9–33.1% SL; gill rakers 28–34; 100–
130mm SL specimens without posterodorsally canted
ring on caudal peduncle ......................... E. denticulatus
Comparative materials. Epigonus denticulatus: AMS
I.21669-005, 2 specimens, 124.0–132.3 mm SL, 33°31′S,
152°04′E, New South Wales, Australia, 28 September 1977;
AMS I.29540-002, 125.3mm SL, 35°32′S, 150°46′E, New
South Wales, Australia, 10 August 1977. Epigonus exodon:
NTUM 13370, 131.0mm SL, 13°03′S, 45°01′E, south of
Mayotte, western South Indian Ocean, 504m depth, 27
January 2017. Epigonus carbonarius: holotype, MNHN
2010-983, 95.3mm SL, female, 08°58′S, 140°04′W, off
Nuku Hiva Island, Marquesas Islands, 391–408m depth,
24 August 1997. Epigonus macrops: AMS I.22814-018,
131.6 mm SL, northwest of Port Headland, Western
Australia, Indian Ocean, 704 m depth, 6 April 1982;
AMS I.31161-004, 170.5 mm SL, off Cape Cuvier,
Western Australia, Indian Ocean, 901m depth, 28 January
1991. Epigonus occidentalis: UF 109570, 3 specimens,
69.8–88.2mm SL, 24°14.1′N, 82°23.7′W, Florida Keys,
534 m depth, 8 June 1994; UF 113906, 2 specimens,
68.2–80.0mm SL, 24°12.3′N, 82°37.5′W, Florida Keys,
559–577m depth, 16 June 1998; UF 180268, 67.0mm SL,
24°20.5′N, 83°14.5′W, Florida Keys, 144–157m depth,
23 April 2003; UF 211404, 15 specimens, 60.3–92.9mm
SL, 14°23.0′N, 81°45.0′W, Caribbean Sea, 5 June 1962;
UF 229213, 12 specimens, 61.2–187.5mm SL, 14°35.0′N,
81°32.0′W, Caribbean Sea, 450–576m depth, 31 January
1971. Epigonus oligolepis: UF 43252, 6 specimens,
104.5–150.3mm SL, 26°11′N, 84°43′W, Gulf of Mexico,
Florida, 300 m depth, 19 September 1985. Epigonus
pandionis: UF 221291, 4 specimens, 136.7–182.0mm SL,
03°45′N, 08°03′E, Equatorial Guinea, western Atlantic,
409–485m depth, 14 May 1965; UF 221434, 19 specimens,
51.2–61.3mm SL, 03°49′N, 07°38′E, Equatorial Guinea,
western Atlantic, 264–269m depth, 14 May 1965; UF
222947, 3 specimens, 162.9–180.0mm SL, Caribbean Sea,
373–434m depth, 14 July 1966. Epigonus pectinifer: HUMZ
190275, 67.1mm SL, 08°10′3″S, 109°49′3″E–08°09′4″S,
109°48′8″E, off Java, Indonesia, 280–285m depth, 13
September 2004.
Supplementary Information The online version contains supplemen-
tary material available at https:// doi. org/ 10. 1007/ s10228- 024- 00948-2.
Acknowledgments We are most grateful to the following persons and
institutions for specimen loans: M. McGrouther, A. Hay, and S. Reader
(AMS); M. Yabe, H. Imamura, F. Tashiro, and T. Kawai (HUMZ); P.
Pruvost and R. Causse (MNHN); J. Williams, E. Wilbur, D. Pitassy,
and K. Murphy (USNM), W.-J. Chen, M.-Y. Lee, H.-S. Lin, and J.-N.
Chen (NTUM); L. M. Page, R. H. Robins and R. A. Singer (UF). We
also thank M. Matsunuma (Kyoto University Museum), G. Shinohara
and K. Fujiwara (National Museum of Nature and Science, Tsukuba)
for taking x-rays. B. Brandt, B. Brown, T. Christiaan, L. Schenk, A.
‘‘Dutch’’ Schrier, and B. van Bebber assisted in various ways with
submersible operations; C. Castillo and T. Devine provided project
management and DNA technician services for DROP. M. Girard for
capturing and editing video. This is Ocean Heritage Foundation/Cura-
cao Sea Aquarium/Substation Curacao (OHF/SCA/SC) contribution
number OHF/SCA/SC#55.
Declarations
Conflicts of interest This paper has no conflict of interest.
Ethics approval Fish species, treated in this study, are not listed as
threatened or endangered by the IUCN Red List or CITES. Specimens
registered in fish collections of natural history museum were used in
this study.
References
Abramov AA (1987) A new Epigonus species (Perciformes, Epigoni-
dae) from the southern Pacific. Vopr Ikhtiol 27:1010–1013
Abramov AA (1992) Species composition and distribution of Epigonus
(Epigonidae) in the world ocean. J Ichthyol 32:94–108
Abramov AA, Manilo LG (1987) Epigonus angustifrons sp. n., a
new cardinal fish (Perciformes, Apogonidae) from submarine

M. Okamoto etal.
mountain ridges in the subtropical zone on the Indian Ocean. Bull
Mos Soc Nat Biol Ser 92:45–48
Ahlstrom EH, Butler JL, Sumida BY (1976) Pelagic stromateoid fishes
(Pisces, Perciformes) of the eastern Pacific: kinds, distributions,
and early life histories and observations on five of these from the
North-west Atlantic. Bull Mar Sci 26:285–402
Brauer A (1906) Die Tiefsee-Fische. I. Systematischer Teil. In: Chun C
(ed) Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expe-
dition “Valdivia”, 1898–99. Volume 15. Gustav Fischer, Jena, pp
1–432, pls 1–18
Dieuzeide R (1950) Sur un Epigonus nouveau de la Méditerranée
(Epigonus denticulatus nov. sp.). Bull Trav Publ Sta Aquic Peche
Castiglione 2:87–105
Gon O (1985) Two new species of the deepsea cardinalfish genus
Epigonus (Perciformes, Apogonidae) from the Hawaiian Islands,
with a key to the Hawaiian species. Pac Sci 39:221–229
Gon O (2003) Epigonidae, deepwater cardinalfishes. In: Carpenter KE
(ed) FAO species identification guide for fishery purposes. The
living marine resources of the western central Atlantic. Volume
3: Bony fishes part 2 (Opistognathidae to Moridae). FAO, Rome,
pp 1392–1394
Goode GB, Bean TH (1881) Description of a new species of fish, Apo-
gon pandionis, from deep water off the mouth of Chesapeake Bay.
Proc U S Nat Mus 4:160–161
Goode GB, Bean TH (1896) Oceanic ichthyology, a treatise on the
deep-sea and pelagic fishes of the world, based chiefly upon the
collections made by the steamers Blake, Albatross, and Fish Hawk
in the north-western Atlantic, with an atlas containing 417 figures.
Spec Bull U S Natl Mus 2:1–553
Ida H, Okamoto M, Sakaue J (2007) Epigonus cavaticus (Teleostei:
Perciformes), a new epigonid fish from Palau, western Central
Pacific. Ichthyol Res 54:131–136
Idrees Babu KK, Akhilesh KV (2020) Epigonus indicus, a new spe-
cies of deepwater cardinalfish (Perciformes: Epigonidae) from the
Indian Ocean. J Ocean Sci Found 36:20–27
Jordan DS, Jordan EK (1922) A list of the fishes of Hawaii, with notes
and descriptions of new species. Mem Carnegie Mus 10:1–92
Krupp F, Zajonz U, Khalaf MA (2009) A new species of the deepwater
cardinalfish genus Epigonus (Perciformes: Epigonidae) from the
Gulf of Aqaba, Red Sea. Aqua 15:223–227
Mabee PM (1988) Supraneural and predorsal bones in fishes: develop-
ment and homologies. Copeia 1988:827–838
Mayer GF (1974) A revision of the cardinalfish genus Epigonus (Perci-
formes, Apogonidae), with descriptions of two new species. Bull
Mus Comp Zool 146:147–203
Okamoto M (2011) A new species of deepwater cardinalfish, Epigo-
nus mayeri, from the eastern Central Atlantic, and redescription
of Epigonus heracleus Parin and Abramov 1986 (Perciformes:
Epigonidae). Ichthyol Res 58:101–108
Okamoto M (2012) Two new species of the genus Epigonus (Perci-
formes: Epigonidae) from the South Pacific, with a definition of
the Epigonus constanciae group. Ichthyol Res 59:242–254
Okamoto M (2015) Epigonus draco, a new species of deepwater car-
dinalfish (Perciformes: Epigonidae) from the Western Pacific.
Species Divers 20:121–127
Okamoto M (2018) First records of two deepwater cardinalfishes (Per-
ciformes: Epigonidae), Epigonus lifouensis and E. pectinifer, from
Indonesia, eastern Indian Ocean. Species Divers 23:243–248
Okamoto M, Bartsch P, Motomura H (2012) Epigonus merleni, a jun-
ior synonym of Epigonus macrops (Actinopterygii: Perciformes:
Epigonidae). Species Divers 17:123–126
Okamoto M, Chen W-J, Motomura H (2020) New distributional
records of three deepwater cardinalfishes Epigonus angustifrons,
E. denticulatus, and E. exodon (Perciformes: Epigonidae) in the
South Indian Ocean. Cybium 44:165–168
Okamoto M, Gon O (2018) A review of the deepwater cardinalfish
genus Epigonus (Perciformes: Epigonidae) of the Western Indian
Ocea, with description of two new species. Zootaxa 4382:261–291
Okamoto M, Miyamoto K (2022) First record of the epigonid fish
Epigonus elongatus off the coast of Okinawa Island, Japan. Jpn J
Ichthyol 69:43–50
Okamoto M, Motomura H (2011) Epigonus carbonarius, a new spe-
cies of deepwater cardinalfish (Perciformes: Epigonidae) from the
Marquesas Islands, with a redefinition of the Epigonus oligolepis
group. Ichthyol Res 58:155–160
Okamoto M, Motomura H (2012) Epigonus exodon, a new species of
deepwater cardinalfish (Teleostei: Perciformes: Epigonidae) from
Réunion, western Indian Ocean. Zootaxa 3453:84–88
Okamoto M, Motomura H (2013) Two new species of deepwater car-
dinalfish from the Indo-Pacific, with a definition of the Epigo-
nus pandionis group (Perciformes: Epigonidae). Ichthyol Res
60:301–311
Parin NV, Abramov AA (1986) Two new species of the bathypelagic
fishes of the genus Epigonus (Apogonidae) from the western
tropical part of the Indian Ocean. Byull Mosk Obsh Ispyt Prir
Otd Biol 91(3):53–57
Rafinesque CS (1810) Indice d’ittiologia siciliana; ossia, catalogo
metodico dei nomi latini italiani, e siciliani dei pesci, che si
rinvengono in Sicilia: disposti secondo un metodo naturale e
seguito da un appendice che contiene la descrizione di alcuni
nuovi pesci siciliani. Presso Giovanni del Nobolo, Messina
Risso A (1810) Ichthyologie de Nice, ou histoire naturelle des poisons
du départment des Alpes Maritimes. Chez F Schoell, Paris
Sabaj MH (2020) Codes for natural history collections in ichthyology
and herpetology. Copeia 108:593–669
Seutin G, White BN, Boag PT (1991) Preservation of avian blood and
tissue samples for DNA analyses. Can J Zool 69:82–90
Weigt LA, Driskell AC, Baldwin CC, Ormos A (2012) DNA barcoding
fishes. Chapter6. In: Kress WJ, Erickson DL (eds) DNA bar-
codes: methods and protocols. Humana Press, New Jersey, pp
109–126
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