Hypoplectrus randallorum, Lobel, Phillip S., 2011

Lobel, Phillip S., 2011, A review of the Caribbean hamlets (Serranidae, Hypoplectrus) with description of two new species, Zootaxa 3096, pp. 1-17: 7-10

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http://doi.org/ 10.5281/zenodo.207418

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Hypoplectrus randallorum

n. sp.

Hypoplectrus randallorum  n. sp.

( Figs. 5View FIGURE 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 AY 262253View Materials). MCZ 169204, 70.9 mm SL collected with MCZ 169203, (GenBank AY 262252View Materials).

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).

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. 5View FIGURE 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. 7View FIGURE 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. 7View FIGURE 7.

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  .


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