Gymnothorax baranesi, a new moray eel (Anguilliformes: Muraenidae) from the Red Sea
Author
Smith, David G.
Author
Brokovich, Eran
Author
Einbinder, Shai
text
Zootaxa
2008
1678
63
68
journal article
10.5281/zenodo.180363
645462c6-7f1f-49d3-beec-d5e33a9f73bb
1175-5326
180363
Gymnothorax baranesi
n. sp.
(
Figs. 1–4
)
Holotype
:
HUJ
18976 (male,
857 mm
TL), Red Sea, Gulf of Aqaba,
29°29'33.0" N
, 34°55.07.8" E,
200 m
, S. Einbinder,
23 April 2002
.
Paratypes
:
HUJ
18975 (1: 762), Red Sea, Gulf of Aqaba,
29°29'37.7" N
,
34°55'10.7"E
,
200 m
, S. Einbinder,
22 February 2002
;
USNM
388603 (1: 828), Red Sea, Gulf of Aqaba, Same locality,
200 m
, S. Einbinder and E. Brokovich,
3 August 2005
.
Diagnosis
. A moderately large moray of the subfamily
Muraeninae
with a color pattern of irregular, complex, rosette-like pale spots on a brown background, the spots becoming smaller on head. Intermaxillary teeth in one peripheral and one median row. Maxillary teeth in 1–2 rows, the inner row, when present, consisting of only two depressible teeth. Mandibular teeth in one row. Vertebrae 6–7, 52–55, 137–142.
FIGURE 1.
Gymnothorax baranesi
, holotype, 857 mm TL, HUJ 18976.
Description
. Proportional measurements in percent of TL: preanal 47–49 (47), predorsal 12–13 (13), head 13–15 (13), depth at gill opening 5.6–8.3 (8.3), depth at anus 5.3–7.0 (7.0); in percent of head: snout 18– 21 (21), upper jaw 39–41 (39), eye 7.6–9.4 (7.6), interorbital 10–12 (12). Meristic characters: predorsal vertebrae 6–7 (7), preanal vertebrae 52–55 (52), total vertebrae 129+–142 (137).
A moderately stout moray eel with the anus slightly anterior to midlength. Dorsal and anal fins continuous with caudal fin, anal fin beginning immediately behind anus, dorsal fin beginning slightly anterior to gill opening. Jaws and snout moderately slender, arched in middle and not closing completely, teeth visible when mouth closed, this condition most obvious in the large
holotype
, upper and lower jaws nearly equal in length. Gill opening approximately midlateral in position. Anterior nostril tubular, short, not reaching edge of upper lip when depressed ventrally; posterior nostril small, elliptical, without a raised rim, located just above eye, about level with anterior margin of eye. Six pores in preoperculomandibular canal, all anterior to rictus; three supraorbital pores, one just above edge of upper lip anterior to anterior nostril, one just medial to anterior nostril, and one on dorsolateral surface of snout at a point between a third and a half of distance between tip of snout and eye; four infraorbital pores, one just posteroventral to anterior nostril, two just above upper lip between anterior nostril and eye, and one just anterior to a vertical through posterior margin of eye; two pores at anterior end of lateral-line canal, anterodorsal to gill opening.
FIGURE 2.
Head of holotype.
All teeth smooth, without serrations. Intermaxillary teeth in one peripheral and one median series: each
paratype
with 5 peripheral teeth on right and 7 teeth on left, continuous around anterior end of upper jaw, fixed, the anterior ones conical, posterior ones more triangular, a few tiny teeth around the base of the larger ones; a single median series of 1–3 depressible teeth (
3 in
holotype
), long, slender, needle-like, the posterior tooth the longest. Maxillary teeth in the two
paratypes
biserial, the inner row with two long, depressible teeth, the outer row with 14–17 shorter, fixed, triangular, slightly recurved teeth, the anterior and posterior ones smaller, those in the middle of the series larger, a distinct gap between maxillary and intermaxillary teeth. In
holotype
, maxillary teeth uniserial, inner row absent; outer teeth large, triangular, posterior ones smallest, middle and anterior ones larger; maxillary teeth continuous with peripheral intermaxillary teeth, without a noticeable gap, the teeth in the two series about equal in size, a combined total of 18 on each side. Vomerine teeth small, 3–12, in a staggered row. Mandibular teeth all fixed, the anteriormost nearly conical, the remain- der triangular, recurved, 17–24 on each side (
17–19 in
holotype
), the anterior teeth the largest; a few tiny teeth around base of large anterior teeth.
Head, body and tail brown, covered with moderate-sized pale spots. Spots discrete and irregularly rounded near end of tail, in approximately three irregular rows; anteriorly, the spots become more irregular in shape, with irregular borders, forming lichen-like or composite, rosette-like markings; the spots largest around midbody, becoming much smaller on head, inconspicuous or absent on snout and lower jaw; spots extend onto fins. Fins without a pale margin. Brown streaks in branchial area. Anterior nostril tube dark brown or black. Head pores narrowly outlined by dark rings. Gill opening somewhat darker than surrounding area. A dark slash at angle of jaw.
Sex and sexual dimorphism
. The
holotype
is a male, with recognizable but not greatly enlarged testes. The HUJ
paratype
has been gutted, and nothing remains of the viscera. The USNM
paratype
, intermediate in size, is immature, and its sex cannot be determined. It appears, then, that
Gymnothorax baranesi
matures at a relatively large size, larger than the specimens described here. Sexual dimorphism has been reported in the dentition of several moray eels (
Collette, et al., 1991
: 347). Adult males have larger and fewer maxillary and mandibular teeth than females and immatures, and the inner maxillary teeth are lost. The evidence indicates that
Gymothorax baranesi
follows this pattern. In the adult male
holotype
the inner maxillary teeth are absent and the outer teeth are enlarged and continuous with those of the intermaxillary series. Both
paratypes
retain the inner maxillary teeth, and the outer maxillary teeth are smaller and more numerous. The
holotype
has 18 teeth in the combined outer maxillary and peripheral intermaxillary series, whereas the two
paratypes
have19– 21. The
holotype
has 17–19 mandibular teeth, whereas the
paratypes
have 19–24. One of the
paratypes
is sexually immature, thus conforming to the pattern of having more and smaller teeth than the adult male. The other
paratype
is indeterminate, but its dentition indicates that it is either a female or an immature male.
FIGURE 3.
Gymnothorax baranesi
, paratype, 762 mm, HUJ 18975.
Distribution
. Known only from the northern Red Sea (Gulf of Aqaba), in moderately deep water, ca.
200 m
.
Etymology.
Named for Dr. Albert (Avi) Baranes of the Hebrew University of Jerusalem, in recognition of his contributions to our knowledge of the fishes of the Red Sea.
Comparisons
.
Gymnothorax baranesi
is one of an indeterminate number of moray species in the western Indian Ocean that are characterized by pale spots on a dark background. Of these,
Gymnothorax meleagris
Shaw
in
Shaw and Nodder, 1795
is the most distinct. The maxillary teeth are biserial, with the inner and outer series about equal in length, and the intermaxillary teeth are arranged in a peripheral series, a median series, and an intermediate series on each side between the median and peripheral series.
Gymnothorax eurostus
(
Abbott, 1860
)
, known in the western Indian Ocean only south of
Mozambique
, has similar dentition to that of
G. meleagris
, and it has small, simple, pale spots, but it also has dark spots underlying the pale spots.
In the remaining species, the maxillary teeth are either uniserial or with an inner series much shorter than the outer, and the intermaxillary teeth consist of a peripheral series on each side, continuous around the front of the jaw, and a single median series.
Gymnothorax nudivomer
(Günther in
Playfair and Günther, 1867
) has simple spots, a relatively short, blunt snout, and the lining of the mouth is bright yellow in life. Larger specimens lack vomerine teeth and median intermaxillary teeth, and the largest teeth are finely serrate; the jaws are not arched, even in large specimens.
Gymnothorax sokotrensis
Kotthaus, 1968
is known from a single specimen collected in the northwestern Indian Ocean. It differs from
G. baranesi
in having simple spots, serrate teeth and more preanal vertebrae (62 vs 52–55).
Gymnothorax johnsoni
(
Smith, 1962
)
was described from off
South Africa
and
Mozambique
, and
G. punctatus
Bloch and Schneider, 1801
was described from off southern
India
. Both these species have similar vertebral counts (and similar to that of
G. baranesi
). They appear to differ mainly in the size of the pale spots, with
G. j o h n s o n i
having larger spots than
G. punctatus
.
Smith (1962: pl. 56 C, D)
presented photographs of both the
holotype
and
paratype
of
G. johnsoni
.
Bloch and Schneider (1801: 526)
did not illustrate
G. punctatus
, but
Day (1878: pl 173, fig. 1)
presented an illustration.
Randall and Golani (1995)
presented accounts, including photographs, of both species based on specimens collected in the Red Sea. Based on both Smith's and Randall and Golani's photographs, the spots in
G. johnsoni
decrease in size and increase in number with increasing size of the specimen. Two specimens from
Somalia
(USNM 301970) tentatively identified by the first author as
G. johnsoni
differ from these in having the spots larger and much more closely spaced anteriorly, with the interspaces reduced to narrow, dark reticulations. Whether all of these specimens belong to the same species is uncertain, and more material is needed to establish the range of variation. All of them, however, differ from
Gymnothorax baranesi
in having simple, discrete spots rather than the complex markings found in the latter.
Among extralimital species,
Muraena helena
Linnaeus, 1758
from the eastern Atlantic and Mediterranean has a similar color pattern of pale, irregular, rosette-like spots on a dark background.
Muraena helena
, however, has tubular posterior nostrils, and it has more vertebrae (142–148;
Jiménez, et al., 2007
).
FIGURE 4.
Dentition of holotype (A) and HUJ paratype (B).
The condition of the jaws in
Gymnothorax baranesi
, highly arched in the middle and not closing completely, raises the question of why we have not placed this species in the genus
Enchelycore
, which is characterized by such arched jaws. The species of
Enchelycore
, however, have a distinctly different pattern of dentition. In
Enchelycore nigricans
Kaup
, the
type
species of the genus, the intermaxillary teeth are arranged in a peripheral series, a median series, and on each side an intermediate series of long, depressible teeth more or less continuous with a long series of similar teeth on the inner row of the maxilla. The outer intermaxillary and maxillary teeth are more conical and less triangular.
Gymnothorax baranesi
has teeth typical of a large group of
Gymnothorax
species, i.e., a peripheral and a single median series of intermaxillary teeth, a short inner row of maxillary teeth, and the outer maxillary teeth distinctly triangular. In addition,
Enchelycore
species tend to be more slender in the snout and jaws. Individuals of other
Gymnothorax
species sometimes have arched jaws as well, and the genus
Enchelycore
probably needs to be defined more precisely than just on the condition of the jaws.