Alpheus angulosus McClure, 2002

Anker, Arthur, 2012, Revision of the western Atlantic members of the Alpheus armillatus H. Milne Edwards, 1837 species complex (Decapoda, Alpheidae), with description of seven new species, Zootaxa 3386 (1), pp. 1-109: 31-35

publication ID

http://doi.org/ 10.11646/zootaxa.3386.1.1

persistent identifier

http://treatment.plazi.org/id/03A41310-FF8E-7D6C-16FC-FBE91A45F819

treatment provided by

Felipe

scientific name

Alpheus angulosus McClure, 2002
status

 

Alpheus angulosus McClure, 2002  

( Figures 19–26, 64D, 65D, 66D, 67D, 68E, F, 69F)

Alpheus angulatus   (nec A. strennus var. angulatus Coutière 1905   ) McClure 1995: 85, figs. 1, 2.

Alpheus angulosus McClure, 2002: 368   ; Mathews 2007: 471; Spence & Knowlton 2008: 208, fig. 3a, 4a, 6–8.

Alpheus cf. angulosus   — Rodrigues et al. 2009: 336.

Alpheus cf. angulosus   A1, A2, A3— Mathews & Anker 2009: 277.

Crangon armillatus   (not H. Milne Edwards 1837) — Hay & Shore, 1918: 386, fig. 9, pl. 27, fig. 1.

(?) Alpheus armillatus   — Williams 1965: 67 (part.?); Chace 1972: 62 (part.?); Hendrix 1971: 59, 60 (part., yellow colour pattern); Coelho & Ramos 1972: 149 (part.?); Williams 1984: 92, fig. 63 (part.); Christoffersen & Ramos 1988: 63, 65 (part., banded-spotted type); Christoffersen 1998: 356 (part.); Coelho et al. 2006: 51 (part.?).

Material examined. Panama: 1 male (cl 9.6), MNHN-IU-2010-4072, Bocas del Toro   , Isla Carenero, near Bucaneer , sand flat with seagrass and rocks and coral rubble, under rocks and rubble, 0.5 m, leg. A. Anker, 17.10.2005   [fcn 05-182]; 1 female (cl 8.4), MNHN-IU-2010-4073, same collection data [fcn 05-188]   ; 1 ov. female (cl 8.3), RMNH D54812 View Materials , same collection data [fcn 05-180]   ; 1 male (cl 7.4), RMNH D54813 View Materials , Bocas del Toro   , Isla Carenero, near Bucaneer , sand flat with seagrass and rocks and coral rubble, under rocks and rubble, 0.5 m, leg. A. Anker, 25.10.2005   [fcn 05-183]; 1 male (cl 7.4), UP   , Isla Grande , southern coast near Playa de la Punta, sand flat with abundant seagrass patches, rocks and rubble, under coral rocks and rubble, 0.5–1 m, leg. A. Anker, 21.04.2006   [fcn 06-403]; 1 ov. female (cl 9.7), MNHN-IU-2010-4074, Isla Grande , southern coast near Playa de la Punta, sand flat with abundant seagrass patches, rocks and rubble, under coral rocks and rubble, 0.5–1.5 m, leg. A. Anker, 04.09.2006   [fcn 06-429]; 1 male (cl 7.1), UP, same collection data [fcn 06-432]   ; 1 ov. female (cl 9.2), RMNH D54814 View Materials   , Isla Grande , lighthouse bay on north coast, large sand flat with rubble, leg. A. Anker, 05.09.2006   [fcn 06- 447]. Costa Rica: 2 males (cl 7.2, 8.2), 2 ov. females (cl 7.1, 8.6), OUMNH. ZC. 2011-06-045, Cahuita, Puerto Var- abundant rubble, clumps of Halimeda   , seagrass, less than 1 m, leg. A. Anker, 26- 27.11.2005   [fcn 05-185]. Mexico: 1 ov. female (cl 8.5), OUMNH. ZC. 2012-03-0005, southern Gulf of   Mexico off Yucatan, Arrecife Alacranes   , Isla Perez , 22º 22' 48.9'' N, 89º 40´58.2'' W, under rubble, 0.5–1 m, leg. N. Simões et al., 12.06.2008 GoogleMaps   [fcn ALA082 = 08- 252]   ; 1 male (cl 7.1), OUMNH. ZC. 2012-03-0006, same collection data [fcn ALA084 = 08-251]   ; 1 ov. female (cl 9.6), OUMNH. ZC. 2012-03-0007, southern Gulf of   Mexico off Yucatan, Arrecife Alacranes   , Isla Perez , 22º 22' 48.9'' N, 89º 40´58.2'' W, under rubble, 0.5–1 m, leg. N. Simões et al., 12.06.2008 GoogleMaps   [fcn ALA-083 = 08-244]; 1 ov. female (cl 6.0), OUMNH. ZC. 2012-03-0008, southern Gulf of   Mexico off Yucatan, Arrecife Alacranes   , Isla Perez , 22º 22' 48.9'' N, 89º 40´58.2'' W, under rocks, 0.5–1 m, leg. N. Simões et al., 12.06.2008 GoogleMaps   [fcn ALA-069 = 08-250]. Cuba: 9 males (cl 6.7–9.4), 5 ov. females (cl 6.1–9.5), 1 female (cl 8.0), OUMNH. ZC. 2011-06-029, Matanzas, Playa Girón, intertidal, sand-rocks, leg. A. Anker, 01.2003 [fcn 03-024, 03-025]   . British Virgin Islands: 1 male (cl 7.9), LACM-MBPC 11729, Guana Island, White Bay , sta. TZ-BI-98-001, 190 m east of beach house, snorkeling 10–40 m off beach, sand and coral rubble, 1–2 m, leg. T. Zimmerman, 19.07.1998   . Haiti: 1 male (cl 9.0), MNHN- Na 2171, locality not specified, leg. M. Ricord, year unknown   . Guadeloupe: 1 male (cl 7.9), 1 ov. female (cl 6.7), MNHN-IU-2010-4075, Grande Terre , between Sainte-Anne and Pointe des Chateaux, small lagoon near mangroves, intertidal, under rocks, leg. A. Anker, 05.2004 [fcn 04-022]   . St. Maarten: 1 male (cl not measured), RMNH D41990 View Materials , oyster pond, 0.3–0.6 m, leg. P.A. van den Heuvel, 22.07.1984   . USA: 1 male (cl 8.5), 1 ov. female (cl 7.9), OUMNH. ZC. 2011-06-030, Florida Keys, Bahia Honda , ocean side, north side of channel, 0.5 m, under rocks, leg. A. Anker, C. Hurt, A.L. Rhyne, 25.09.2007   [fcn 07-284]; 1 ov. female (cl 8.7), RMNH D54816 View Materials , same collection data [fcn 07-296]   ; 1 male (cl 8.7), MNHN-IU-2010-4076, same collection data [fcn 07-283]   ; 2 males (cl 6.3, 9.8), MNHN-IU-2010-4077, Florida, Cedar Key , oyster beds with mud, under rocks and oyster clumps, low tide, leg. A. Anker, 29.09.2007   [fcn 07-268]; 1 male (cl 7.1), 1 female (cl 7.5), RMNH D54817 View Materials , same collection data [fcn 07- 269]   ; 1 male (cl 8.8), 1 ov. female (cl 8.1), MNHN-IU-2010-4078, same collection data [fcn 07-267]   ; 1 ov. female (cl 8.0), OUMNH. ZC. 2011-06-031, same collection data [fcn 07-272]   ; 1 male (cl 10.7), 1 ov. female (cl 11.2), OUMNH. ZC. 2011-06-032, Florida, Cedar Key, oyster beds with mud, under rocks and oyster clumps, low tide, leg. J.A. Baeza, 07.07.2007   [fcn 07-241]; 1 male (cl 8.8), MNHN-IU-2010-4079, Florida, near Melbourne , intertidal, under rocks, leg. A. Anker, A.L. Rhyne, 28- 29.09.2007   [fcn 07-274]; 1 male (cl 6.7), RMNH D54818 View Materials , same collection data [fcn 07-279]   ; 1 male (cl 9.4), OUMNH. ZC. 2011-06-033, same collection data [fcn 07-271]   ; 1 male (cl 8.5), MZUSP 25233 View Materials , same collection data [fcn 07-273]   ; 1 male (cl 7.9), MNHN-IU-2010-4080, same collection data [fcn 07-270]. French   Guyana: 1 male (cl 11.0), 1 ov. female (cl 12.6), MNHN-Na 14203, Anse de Montabo , Mission F. Geay, N 2620, 12.1901   . Brazil: 1 male (cl 8.1), 1 ov. female (cl 9.2), MZUSP 25234 View Materials , Ceará, Praia de dois Coqueiros , rocky shore exposed at low tide, on sand under large rocks, leg. A. Anker, 24.05.2011   [fcn 11- 010]; 1 male (cl 10.4), Ceará, Camocim, Praia do Farol de Trapiá , OUMNH. ZC. 2012-07-023, sand-rock intertidal, low tide, under rocks, leg. P. Pachelle, 08.04.2012   [fcn 12-003]; 1 female (cl 5.8), 1 ov. female (cl 6.4), 1 juv. female (cl 3.8), MNRJ 23321 View Materials , Atol das Rocas, in front of   Ilha do Farol , under large rocks, coll. P.S. Young, P.C. Paiva, A.A. Aguiar, 14.10.2000   ; 1 ov. female (cl 6.4), MNRJ 17922 View Materials , Atol das Rocas, northeast coast of   Ilha do Farol , in tide-pool, coll. C. Serejo, M.C. Rayol, 22.10.2001   ; 3 males (cl 7.7, 8.8, 9.9), 2 ov. females (cl 9.3, 10.3) MNRJ 17894 View Materials , LT 773, Atol das Rocas, between   Ilha do Farol and   Ilha do Cemitério , low tide, under clumps of algae, coll. C. Serejo, M.C. Rayol, 25.10.2001   ; 1 male (cl 9.7), 2 ov. females (cl 9.8, 11.2), 1 juv. male (cl 4.3), 1 juv. female (cl 3.7), MNRJ 23322 View Materials , LT 800, Atol das Rocas   , Ilha do Cemitério , intertidal, coll. C. Serejo, M.C. Rayol, 20.10.2001   ; 1 female (cl 5.0), 1 ov. female (cl 7.4), MNRJ 23323 View Materials , LT 795, Atol das Rocas, between   Ilha do Farol and   Ilha do Cemitério , low tide, coll. C. Serejo, M.C. Rayol, 31.10.2001   ; 1 immature female, MNRJ 23324 View Materials , LT 702, Atol das Rocas, between Piscina das Tartarugas and Piscina das Rocas , in tide pools among calcareous algae, coll. P.S. Young, P.C. Paiva, A.A. Aguiar, 28.10.2000   ; 3 males (cl 6.8, 8.3, 8.6), 1 ov. female (cl 9.8), 1 female (cl 7.3), MNRJ 23325 View Materials , Atol das Rocas, Piscina das Rocas, calcareous algae, coll. C. Serejo, M.C. Rayol, 26.10.2000   ; 1 male (cl 12.0), MZUSP 4869 View Materials , Rio Grande do Sul , Torres, leg. J. Bertoletti, 05.11.1964   ; 1 ov. female (cl 11.0), MZUSP 5333 View Materials , Rio de Janeiro , Angra dos Reis, leg. G. S. de Melo, 21.05.1966   .

Material identified as Alpheus cf. angulosus   : Brazil: 1 male (cl 10.5), OUMNH. ZC. 2012-03-010, near Pedra do Garapira, Atol das Rocas, Brazil, in tide pool, coll. P.S. Young, P.C. Paiva, A.A. Aguiar, 14.10.2000   .

Diagnosis. Rostrum straight, reaching at least half-length of first article of antennular peduncle; area posterior to rostral carina flattened, markedly but not abruptly delimited from adjacent, relatively shallow rostro-orbital furrows, forming more or less V-shaped post-rostral plate continuous with relatively broad, blunt rostral carina, margins of post-rostral plate not overhanging rostro-orbital furrows; post-rostral plate situated at about the same level as rostral carina or slightly above it, in latter case gently sloping. Antennule with stylocerite acute distally, overreaching distal margin of first article; ventromesial carina of first article with tooth bearing small subacute point on anterior margin; second article about twice as long as wide. Antenna with basicerite armed with stout, sharp distolateral tooth; scaphocerite with broadly concave lateral margin, strong distolateral tooth reaching well beyond moderately broad blade; carpocerite exceeding scaphocerite blade but not (or very slightly) distolateral tooth, reaching slightly past end of antennular peduncles. Third maxilliped with ultimate article as broad as penultimate, tapering distally. Major cheliped edwardsii   - type (see under A. armillatus   ). Male major cheliped with merus stout, distodorsal margin ending bluntly, ventromesial margin smooth, without stout spiniform setae distally, with strong, acute or subacute distomesial tooth; palm with dorsal shoulder rounded, sloping obliquely into adjacent transverse groove, not overhanging groove; ventral shoulder broadly rounded, not projecting, smooth laterally; fingers more than halflength of palm; pollex without ridge mesially; dactylus plunger large, stout, proximal height about 0.7 length of distolateral margin, anterior angle slightly more than 90°. Female major cheliped usually smaller than male major cheliped, with chela smaller, less stout, and with different proportions. Male minor cheliped with merus moderately stout, distodorsal margin blunt, ventromesial margin without spiniform setae, with small, sharp distomesial tooth; chela moderately stout, palm with length-height ratio about 2.0; palm without longitudinal depressions, with slight sinus on ventral margin; fingers about as long as palm, rather slender, simple, non-balaeniceps, with sharp cutting edges. Female minor cheliped generally similar to male minor cheliped, more slender; palm without or with very faint ventral sinus. Second pereiopod slender, with first two carpal articles longest, first about 1.4 length of second. Third and fourth pereiopods similar, moderately stout; ischium with spiniform seta ventrolaterally; merus slightly more than four times as long as wide; propodus with stout spiniform setae, sometimes inserted in pairs, along ventral margin, incuding one pair adjacent to dactylus; dactylus about 0.4 length of propodus, simple, conical. Fifth pereiopod much more slender than third and fourth; ischium unarmed in both sexes. Sternum at the base of fourth pereiopods without conspicuously projecting, slender, subacute processes. First abdominal sternite with small, blunt median process, second sternite unarmed in males; both first and second sternites unarmed in females. First to fourth pleopods without spiniform setae on ventrolateral margin of protopod in both sexes; male second pleopod with appendix masculina not exceeding appendix interna, densely covered with stiff setae, especially on apex. Uropod with exopod and endopod broadly rounded; exopod with sinuous diaeresis and stout distolateral spiniform seta; endopod with row of small spiniform setae on distal margin. Telson broad, slightly tapering posteriorly; dorsal surface with two pairs of spiniform setae inserted far from lateral margins; posterior margin broadly rounded, with row of small spiniform setae; posterolateral angles each with two spiniform setae, mesial much longer than lateral ( Fig. 19–21; see also McClure 1995 for additional figures).

Variation. The most important morphological variation in A. angulosus   affects the size and shape (proportions) of the major cheliped between the males and the females, and between younger and older individuals ( Fig. 20A, G; see also Figs. 23, 24). There is also some variation in the elevation of the post-rostral plate in relation to the rostro-orbital furrows and especially its width, i.e. a broader or a narrower V-shape ( Figs. 19A, 21A). The postrostral plate is generally slightly higher and more abruptly marked in larger specimens, and lower, more subtly delimited in younger specimens.

Size range. The present specimens range from 6.7 to 10.7 mm cl in males, and from 6.7 to 11.2 mm cl in females.

Colour pattern. Body background colour variable, often straw-yellow, pale greenish-yellow, greyish-green, bluish-green, olive-green, greenish-brown, pale brown, or pale bluish-grey; abdomen and carapace dotted with numerous brown-reddish or brownish-greenish chromatophores forming a fine reticulation; post-rostral plate with the same pattern, margins not particularly outstanding, brownish-greenish; antennular and antennal flagella pale blue-greenish; chelipeds with ischium, merus and carpus mostly whitish-greenish with some green-brown pattern distally and dorsally; mesial face of major chela with background varying from dark-brown to greenish-brown or olive-grey, with large white or pale green area proximally, dorsal and ventral depressions conspicuously marked by white or pale yellow area; dactylus and pollex greenish or brownish, with some bluish areas; distal portion of dactylus and pollex pinkish; mesial face of minor chela greenish or brownish, with some orange on finger tips; second to fifth pereiopods whitish with reddish chromatophores; telson and uropods as general body colour, exopod with patches of golden-yellow chromatophores; fresh eggs olive-green ( Figs. 22–24); specimens from northern Florida to North Carolina and northern Gulf of Mexico (Alabama, Texas) usually darker, dark-green to brown-green ( Fig. 25); specimens from Brazil ( Fig. 26) generally similar to those from the Caribbean and southern Florida; juveniles usually pale green-yellow with clearly delimited whitish dorsal and ventral depressions on major chela ( Fig. 69F). See also detailed colour description in McClure (1995) and colour photographs in Spence & Knowlton (2008); compare with “yellow colour pattern” in Hendrix (1971, p. 65).

Type locality. South Padre Island , Texas   .

Distribution. Atlantic coast of USA from North Carolina to Florida Keys; Gulf of Mexico from Florida to Texas and south to Yucatan; throughout Caribbean Sea: eastern Yucatan, Belize, Honduras, Costa Rica, Panama, Jamaica, Cuba, Hispaniola, Puerto Rico, St. Martin, Guadeloupe; French Guyana; Brazil: Ceará, Atol das Rocas, Fernando do Noronha, Paraíba, Bahia, Rio de Janeiro, Rio Grande do Sul (see map in Fig. 70 and remarks below).

Ecology. Various intertidal and shallow subtidal habitats at a depth range of 0–5 m; typically on fine sand or rubble-sand with rocks and large pieces of coral rubble, often near coral reefs, seagrass beds or mangroves, also in oyster beds and rocky tide pools, rarely on mud bottoms; typically found under rocks, large pieces of coral rubble, clumps of algae ( Halimeda   and others), or in crevices of coral rocks or coralline algae (younger individuals); typically in male-female pairs.

Remarks. Alpheus angulosus   is part of the large and genetically strongly structured Clade 2 of Mathews & Anker (2009, fig. 4), which is more distantly related to Clade 5 ( A. armillatus   , A. verrilli   ) and Clade 6 ( A. lancirostris   ). Alpheus angulosus   can be distinguished from both A. armillatus   and A. verrilli   by the non-abruptly delimited, V-shaped post-rostral plate, situated only slightly above rostral carina, and with margins not overhanging the adjacent rostro-orbital furrows (vs. more U-shaped post-rostral plate situated much higher than the rostral carina and with overhanging margins in A. armillatus   and A. verrilli   ); the unarmed ischium of the fifth pereiopod in both males and females (vs. armed with a small spiniform seta in in A. armillatus   and A. verrilli   ); and the presence of a small blunt median process on the first abdominal sternite in males only (vs. two strong processes on both first and second abdominal sternites and in both sexes in A. armillatus   and A. verrilli   ). Alpheus angulosus   can also be distinguished from A. lancirostris   , e.g., by the narrower and less abruptly delimited post-rostral plate, with margins not overhanging the adjacent rostro-orbital furrows (vs. broader, more triangular, and slightly overhanging the rostroorbital furrows in A. lancirostris   ); and the ventromesial carina of the first antennular article with a pronounced tooth bearing a small point anteriorly (vs. with a low, blunt tooth in A. lancirostris   ). In life, A. angulosus   can be easily distinguished from A. armillatus   , A. lancirostris   and A. verrilli   , as well as all the species reported below, by the uniform pale greenish or yellowish brown, finely spotted colour pattern (type NB 4 in Mathews & Anker 2009, fig. 2E). Especially diagnostic are the pale beige or whitish patches delimiting the dorsal and ventral depressions of the major chela, present in virtually all specimens examined throughout the species’ distribution range ( Figs. 22–26).

As pointed out by McClure (1995, 2002), many previous records of A. armillatus   , especially those from the Atlantic coast of the USA north of Florida, but also from the Gulf of Mexico and the Caribbean Sea, refer to A. angulosus   , and not to A. armillatus   .

This is also true for many Brazilian records. For instance, Christoffersen & Ramos (1988) reported two colour morphs of A. armillatus   in Brazil, a banded-spotted colour morph (see below), and a uniformly colour morph described as typically green, sometimes with grey or yellowish-brown pigments predominating, matching the colour type NB4 and thus A. angulosus   . The same colour pattern was described for the material from Paraíba reported as A. cf. angulosus   by Rodrigues et al. (2009). The presence of A. angulosus   in Brazil is confirmed in the present study by the abundant material from Atol das Rocas and fresh specimens from Ceará and Bahia accompanied by colour photographs ( Fig. 26).

As mentioned above, A. angulosus   is a genetically diversified taxon that is possibly in the process of speciation. Three major clades can be recognised based on 16S and COI sequence dataset: (1) a subtropical Gulf of Mexico—Florida clade (probably extending to North Carolina); (2) a more tropical South Florida—Caribbean clade; and (3) a Brazilian clade (clades 2b, 2d and 2e, respectively in Mathews & Anker 2009, fig. 4) (see also Fig. 70). A more extensive sampling of populations from the US east coast north of Florida, the western Gulf of Mexico as well as Brazil, is needed to further investigate the phylogeography and speciation processes in A. angulosus   .

One male specimen from Atol das Rocas, Brazil (OUMNH.ZC. 2012-03-010), was tentatively identified as A. 

cf. angulosus. In the phylogeny of Mathews & Anker (2009), this specimen represented the terminal “ A. cf. armillatus   35”, which was recovered within Clade 3 (as sister to one of the below described new species), and distant from Clade 2. However, it appears to be morphologically indistinguishable from other Atol das Rocas specimens identified as A. angulosus   , including two specimens from Clade 2e (see Mathews & Anker 2009, fig. 4). In addition, field notes indicated that this shrimp had a yellowish body with greenish chelae in life, a colour pattern typical to A. angulosus   . This specimen may need to be re-sequenced to confirm its identity (see also below).

GenBank accession numbers. Florida (East coast): DQ682910 View Materials (16S)   FJ528507 View Materials ( COI); Florida (Gulf coast) [not deposited]   : FJ528552 View Materials (myHC)   , DQ682917 View Materials (16S)   , FJ528499 View Materials ( COI) [not deposited]; Puerto Rico   : FJ528451 View Materials (16S)   , FJ528501 View Materials ( COI) [not deposited]; Costa Rica   : FJ528551 View Materials (MyHC)   , FJ528453 View Materials (16S)   , FJ528503 View Materials ( COI) [ OUMNH. ZC. 2011-06-045]; Cuba   : FJ528454 View Materials (16S)   , FJ528504 View Materials ( COI) [ OUMNH. ZC. 2011-06-029]; Panama   : DQ682908 View Materials (16S)   , FJ528505 View Materials ( COI) [ RMNH D54812 View Materials ]; Brazil (Atol das Rocas)   : DQ682849 View Materials (16S)   , FJ528493 View Materials ( COI) [ MNRJ 17922 View Materials ]. Alpheus cf. angulosus (Atol das Rocas)     : FJ528458 View Materials (16S)   FJ528516 View Materials ( COI) [ OUMNH. ZC. 2012-03- 010]   .

eral view; G, same, distal propodus and dactylus, lateral view; H, fifth pereiopod, lateral view; I, diagrammatic representation of first two abdominal sternites, ventroposterior view; J, second pleopod, detail of appendix masculina and appendix interna, lateral view; K, telson, dorsal view; L, uropod, dorsal view. Scale bars as indicated, fig. I drawn without scale.

RMNH

National Museum of Natural History, Naturalis

UP

University of Papua and New Guinea

ZC

Zoological Collection, University of Vienna

T

Tavera, Department of Geology and Geophysics

COI

University of Coimbra Botany Department

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Alpheidae

Genus

Alpheus

Loc

Alpheus angulosus McClure, 2002

Anker, Arthur 2012
2012
Loc

Alpheus cf. angulosus

Rodrigues, F. M. de & Lomonaco, C. & Christoffersen, M. L. 2009: 336
2009
Loc

Alpheus cf. angulosus

Mathews, L. M. & Anker, A. 2009: 277
2009
Loc

Alpheus angulosus

Spence, H. R. & Knowlton, R. E. 2008: 208
Mathews, L. M. 2007: 471
McClure, M. R. 2002: 368
2002
Loc

Alpheus angulatus

McClure, M. R. 1995: 85
1995
Loc

Crangon armillatus

Hay, W. P. & C. A. Shore 1918: 386
1918