A review of the Caribbean hamlets (Serranidae, Hypoplectrus) with description of two new species
Author
Lobel, Phillip S.
text
Zootaxa
2011
3096
1
17
journal article
46008
10.5281/zenodo.207418
bd98869e-e92c-4650-a71f-79124d0b3b3b
1175-5326
207418
Hypoplectrus randallorum
n. sp.
(
Figs. 5
,
6
; Tables 4, 5)
Hypoplectrus
sp “tan”,
Randall & Randall 1960
,
Thresher 1978
,
Domeier 1994
Hypoplectrus
sp “tan”,
Heemstra
et al
. 2002
: page 1368.
Holotype
:
MCZ
169250,
80.6 mm
SL, Carrie Bow Cay,
Belize
, ridge east of cay at 16
0 48.2’ N
, 88
0 4.5’W
,
18 m
depth, reef, spear,
6 June 1993
, J. E. Randall.
Paratypes
:
BPBM
35766,
70.9 mm
SL, collected, with
holotype
.
MCZ
169203
91.4 mm
SL, Glovers Atoll,
10 m
depth, ocean side reef, spear,
21 July 1999
, P. S. Lobel and J. E. Randall (GenBank
AY262253
).
MCZ
169204,
70.9 mm
SL collected with
MCZ
169203, (GenBank
AY262252
).
Diagnosis:
The tan hamlet is distinguished from its congeners by coloration. Its body is uniformly light brown to tan colored. It possesses distinct nose spots, a spot at the base of the pectoral fin and a caudal peduncle spot.
Description:
Dorsal X, 15; anal III, 7; dorsal and anal soft rays branched, the last to base; pectoral rays 14; pelvic I,5; branched caudal rays 17 or 18; vertebrae 23 or 24.
The following morphometrics are given as percentages of the standard length (range, min–max): body depth 45.6% SL (44.2–47.0); body compressed, width 16.6 (16.0–17.8); head length 39.8 (38.5–41.5); snout length 11.3 (10.3–12.2); orbit diameter 10.0 (9.6–10.4); interorbital width 8.9 (7.6–11.0); upper jaw length 17.7 (16.2–18.9); caudal-peduncle depth 14.0 (13.6–14.2); caudal-peduncle length 11.8 (9.9–13.8); predorsal length 43.3 (42.4– 46.4); preanal length 22.1 (16.8–26.9); prepelvic length 42.8 (40.7–44.9); base of dorsal fin 55.4 (49.8–57.7); longest dorsal spine 16.7 (16.1–17.3); base of anal fin 18.8 (16.5–20.7); longest anal spine 14.6 (13.9–15.6); longest anal ray 18.2 (15.3–20.4); caudal fin length 22.8 (21.4–25.9); pectoral fin length 32.1 (31.9–32.4); pelvic fin length 25.9 (22.4–28.6).
FIGURE 5.
Hypoplectrus randallorum
, paratype: MCZ 169203, 91.4 mm SL, Glovers Atoll, 10 m depth, ocean side reef, spear, 21 July 1999, P. S. Lobel and J. E. Randall.
FIGURE 6.
Hypoplectrus randallorum
, Belize.
Other characteristics similar to congeners as described above.
Coloration Live:
Trunk dark to light brown, head more tan colored. The belly, fins and head can sometimes have a faintly yellowish hue. Pectoral fins clear. Distinct nose spots present on nasal area, a dark spot present at base of pectoral fin and a dark spot present on the upper part of caudal peduncle. The size and intensity of spots can vary (
Figs. 5
,
6
).
Coloration Preserved:
Uniformly light brown color. Caudal fin is clear and other fins are pigmented. Spots on nose, pectoral fin base and upper part of caudal peduncle remain visible in preservative (
Fig. 7
).
Etymology:
Named in honor of Helen and John E. Randall, who first recognized the tan hamlet as a possible new species in their 1960 paper. The ending “
orum”
refers to “of man (men) and woman (women)”. J. E. Randall collected the
holotype
.
Remarks:
The “Tan Hamlet” has long been recognized as “another hamlet” by
Randall & Randall 1960
,
Thresher 1978
,
Domeier 1994
,
Heemstra
et al.
2002
,
Ramon
et al
. 2003
,
Aguilar-Perera 2004
,
Nelson 2004
,
Williams
et al
. 2006
,
Aguilar-Perera & Gonzalez-Salas 2010
,
Holt
et al
. 2010
,
Kells & Carpenter 2011
). It is widespread in the western Caribbean from the West Indies to Central
America
(
Heemstra
et al
. 2002
,
Aguilar-Perera & Gonzalez-Salas 2010
,
Holt
et al
. 2010
). Although its body coloration can sometimes be dark,
H. randallorum
differs from the black hamlet by having nose spots. There are several variants of the black hamlet,
H. nigricans
that differ in the coloration of their fins and slightly in some body proportions (
Aguilar-Perera 2004
).
Puebla
et al
. (2008)
proposed, based on DNA data, that
H. nigricans
may actually represent several different lineages that have independently evolved from an ancestral
H. puella
stock during multiple evolutionary events. Three different color variants of
H. nigricans
that have been described by
Aguilar-Perera (2004)
are shown in
Fig. 7
.
FIGURE 7.
Hypoplectrus randallorum
. Holotype MCZ 169250, preserved specimen.
|
TABLE 4.
Proportional measurements
|
of |
Hypoplectrus
|
randallorum
.
Listed
|
by MCZ and BPBM |
number |
|
Specimen
|
169250
Holotype
|
BPBM 35766
Paratype
|
169203
Paratype
|
169204
Paratype
|
| SL, mm |
80.6 |
70.9 |
91.4 |
71.86 |
| Body depth |
45.4 |
46.0 |
47.0 |
44.2 |
| Body width |
16.0 |
16.1 |
17.8 |
16.6 |
| Head length |
40.3 |
39.1 |
41.5 |
38.5 |
| Snout length |
12.2 |
10.6 |
12.2 |
10.3 |
| Orbit diameter |
10.2 |
10.4 |
9.8 |
9.6 |
| Interorbital width |
8.2 |
8.7 |
11.0 |
7.6 |
| Upper-jaw length |
18.0 |
17.6 |
18.9 |
16.2 |
| Caudal peduncle depth |
13.6 |
13.9 |
14.2 |
14.2 |
| Caudal peduncle length |
11.5 |
13.8 |
11.9 |
20.1 |
| Predorsal length |
42.4 |
42.5 |
46.4 |
46.0 |
| Preanal length |
25.5 |
16.8 |
26.9 |
19.1 |
| Prepelvic length |
40.7 |
41.8 |
43.6 |
44.9 |
| Base of dorsal fin |
56.7 |
57.7 |
57.3 |
49.8 |
| Longest dorsal Spine |
16.4 |
17.2 |
16.1 |
17.3 |
| Base of anal fin |
19.4 |
20.7 |
18.7 |
16.5 |
| Longest anal spine |
14.7 |
14.2 |
13.9 |
15.6 |
| Longest anal ray |
20.4 |
18.7 |
18.2 |
15.3 |
| Caudal fin length |
21.6 |
21.4 |
25.9 |
22.1 |
| Pectoral fin length |
32.1 |
31.9 |
32.2 |
32.4 |
| Pelvic fin length |
26.7 |
28.6 |
25.8 |
22.4 |
TABLE 5. Meristic data for
Hypoplectrus randallorum
.
Listed by MCZ and BPBM number.
169250 BPBM 35766 169203 169204
Specimen
Holotype
Paratype Paratype Paratype
Dorsal
X 15
X
15 X 15
X 15 Anal
III 7 III 7 III 7 III 7
Caudal 17 17 18 17 Pelvic
I 5 I 5 I 5 I 5
Pectoral 14 14 14 13 Vertebrae
23 24 23 n
/a
Ecology:
Hamlets are predators of small benthic shrimp, crabs, mysids, stomatopods and tiny fishes (
Randall 1967
). In one study (
Randall 1967
), fishes constituted between 10 to 44.2% of hamlet’s food items with
H. nigricans
having the highest percentage of fishes in its diet. One specimen of
H. randallorum
(
70.2 mm
SL) collected
8 July 1990
on reefs off the Discovery Bay Marine Laboratory in
Jamaica
had a freshly consumed cleaner goby,
Elacatinus evelynae
(
16.5 mm
SL) in its stomach content (personal observation). I have also observed hamlets attack and consume
Elacatinus
spp in
Belize
both in the field and in an aquarium.
Randall (1967)
reported that a Nassau grouper,
Epinephalus guttatus
had eaten one
H. puella
.