Alpheus viridari ( Armstrong, 1949 )

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 : 85-93

Alpheus viridari ( Armstrong, 1949)

( Figs. 60 –63, 65L, 66L)

Crangon viridari Armstrong, 1949: 8 , fig. 2.

Alpheus viridari — Rouse 1970: 137; Hendrix 1971: 147, pls. 23, 24; Chace 1972: 73;

Abele 1976: 273; Carvacho 1979: 455; Rodríguez 1980: 150; Gore et al. 1981: 490; Abele & Kim 1986: 198, 212-213, figs. gi; Rodríguez 1986: 160, fig. 37; Martínez-Iglesias et al. 1993: 11; Ferraris et al. 1994: 397-406; Martínez-Iglesias et al. 1996: 34; Martínez-Iglesias et al., 1997: 424, fig. 17; Mathews & Anker 2009: 272, fig. 6A, 277.

Alpheus viridaris (lap. cal.)—Campos 1995: 61.

Crangon armillatus (not H. Milne Edwards, 1837)— Darby 1934: 349; Darby 1935: 151; Darby 1938: 78; Darby 1939: 61 (at least part.; see Armstrong 1949 and Williams 1984).

Material examined. Panama: 1 male (cl 10.9), MNHN-IU-2010-4099, Isla Grande, southern coast near village, shallow sand flat close to rubble and seagrass beds, 1 m, leg. A. Anker, 21.04.2006 [fcn 06-408]; 1 male (cl 10.2), RMNH D54828, Bocas del Toro, Isla Colón, off STRI dock, sand-mudflat with seagrass and pieces of rubble, suction pump, in burrow, 0.5–1.5 m, leg. A. Anker, 14.08.2008 [fcn 08-240]; 1 male, 1 ov. female (cl not measured), OUMNH. ZC. 2011-06-041, Bocas del Toro, Isla Solarte, sand-mudflat with seagrass, under rubble, 0.5–1 m, leg. A. Anker, 30.10.2005 [fcn 05-137]. Dominican Republic: 1 ov. female (cl 12.5), MNHN-IU-2010-4100, Boca Chica, shallow lagoon-type sand flat with some seagrass and rubble, close to mangrove stands, 1–1.5 m, leg. A. Anker, 05- 06.01.2005 [fcn 05-136]. Belize: 1 male (cl 7.8), 1 ov. female (cl 7.8), OUMNH. ZC. 2009-01-0035, Carrie Bow Cay, Twin Cay, 16°49.424’N 88°06.346’W, in eroded sunken wood, 0.5 m, leg. S. De Grave, 20.02.2009 [fcn CBC-067]. Curaçao: 7 specimens (males and females, cl not measured), USNM 63522, lagoon, 1 fathom (about 1.8 m), small beam trawl, 26.07.1965. British Virgin Islands: 1 male (cl 6.9), LACM-MBPC 11731, Tortola Island, sta. BVI-99 25B, Tortola Island, open anchorage approximately 100 m east of Tortola - Beef Island toll bridge, edge of rock wall near and off mangroves ( Avicennia ), in soft mud/sand bottom (slight smell of H 2 S), dense Halimeda & Caulerpa , 0–1 m, leg. L.H. Harris, 26.07.1999 [fcn LH-0198]. Guadeloupe: 1 male (cl 6.5), OUMNH. ZC. 2011-06-044, Anse du Vieux-Bourg, shallow bay, small, mangrove-fringed island, in dead conch shell, 1–2 m, leg. F. Fasquel, 24.12.1999 [fcn 99-01, dissected]; 1 male (cl 10.0), MNHN-Na 15642, Anse du Vieux Bourg, mangroves, mud bottom, 15.07.2002; 1 female (cl 8.5), MNHN-Na 14148, Canal Perrin, station 2, dredge, 3 m, leg. Guyard-Laubscher, 19.11.1976. St. Martin: 1 ov. female (cl 10.4), FLMNH UF Arthropoda 30332, Réserve Naturelle de Saint-Martin, sta. 37, south side of Baie de l'Embouchure, near drainage of Étang aux Poissons, seagrass with mangroves, leg. A. Anker, J.F. Maréchal, 16.04.2012 [fcn BSTM-0735]; 1 ov. female (cl 9.5), FLMNH UF Arthropoda 30333, same collection data [fcn BSTM-0734]; 2 males (cl 5.9, 6.5), FLMNH UF Arthropoda 30334, Réserve Naturelle de Saint-Martin, sta. 33, Plage du Galion, in burrows and under seagrass mats, 0.5–1 m, leg. A. Anker, J.F. Maréchal, 14.04.2012 [fcn BSTM-0527]; 1 female (cl 6.8), FLMNH UF Arthropoda 30335, Réserve Naturelle de Saint-Martin, sta. 35, Plage du Galion, in burrows and under seagrass mats, 0.5–1 m, leg. A. Anker, J.F. Maréchal, 15.04.2012 [fcn BSTM-0706]; 1 ov. female (cl 7.4), FLMNH UF Arthropoda 30336, same collection data [fcn BSTM-0705]. Mexico: 1 male (cl 7.3), 1 ov. female (cl 8.0), OUMNH. ZC. 2012-03- 0009, Yucatan, Quintana Roo, Mahahual, sand flat with abundant seagrass and some rocks, under large rocks and coral rubble pieces, 0.5 –1.5 m, leg. A. Anker, J. Duarte-Gutiérrez, 06.06.2010 [fcn MAH-022, with hemiarthrine parasite]. USA: 1 male, 1 ov. female (cl not measured), OUMNH. ZC. 2011-06-042, Florida Keys, Little Duck Key, lagoon near mangroves on gulf side, under large rocks on silty sand, 0.5–1 m, leg. A. Anker, 06.09.2008 [fcn 08-268, with bopyrid parasite]; 1 male (cl not measured), OUMNH. ZC. 2011-06-043, Florida Keys, Bahia Honda, ocean side, north side of channel, under rocks, ~ 0.5 m, leg. A. Anker, C. Hurt, A.L. Rhyne, 25.09.2007 [fcn 07- 282]; 1 ov. female (9.0), RMNH D16988, Florida, Virginia Key (near Miami), near Bear Cut marine laboratory, seagrass bed, night, leg. L.B. Holthuis, 15.09.1960.

Diagnosis. Rostrum straight, usually reaching half-length of first article of antennular peduncle; rostral carina narrow, blunt dorsally, inconspicuously flattening posteriorly, not forming a post-rostral plate; rostro-orbital furrows shallow. Antennule with stylocerite acute distally, reaching or slightly overreaching distal margin of first article; ventromesial carina of first article with tooth bearing small subacute point above concave anterior margin; second article about twice as long as wide. Antenna with basicerite armed with stout, sharp distolateral tooth; scaphocerite Third maxilliped with ultimate slightly more slender than 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 spiniform setae, with strong, sharp distomesial tooth; palm with dorsal shoulder rounded, sloping gently and obliquely into adjacent transverse groove, not overhanging groove; ventral shoulder broadly rounded, not projecting, smooth laterally; fingers more than half-length of palm; pollex with small notch on cutting edge, without ridge mesially; dactylus with somewhat angular outline distally, plunger moderately large, stout, proximal height about 0.8 length of distolateral margin, anterior angle more than 90°. Female major cheliped usually smaller than male major cheliped, with chela somewhat smaller and with more or less different proportions. Male minor cheliped with merus rather slender, distodorsal margin blunt, ventromesial margin without spiniform setae, with small, acute distomesial tooth; chela slender, palm with length-height ratio at least 2.5 and usually approaching 3.0; palm without longitudinal depressions laterally or mesially, without ventral sinus, sometimes with slight dorsal sinus; fingers more or less same length as palm, very slender, simple, non-balaeniceps, with sharp cutting edges. Female minor cheliped generally similar to male minor cheliped. Second pereiopod slender, with first two carpal articles longest, first about 1.8 length of second. Third and fourth pereiopods similar, slender; ischium with stout spiniform seta ventrolaterally; merus more than six times as long as wide; propodus with stout spiniform setae, sometimes inserted in pairs, along ventral margin, incuding one pair adjacent to dactylus; dactylus close to half 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 and second abdominal sternites unarmed in both sexes. First to fourth pleopods without spiniform setae on ventrolateral margin of protopod in both sexes; male second pleopod with appendix masculina shorter than appendix interna, densely covered with stiff setae apically and mesially. 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 slender spiniform setae; posterolateral angles each with two stouter spiniform setae, mesial much longer than lateral ( Fig. 60 ; for additional figures see Armstrong 1949 and Hendrix 1971).

Size range. The present specimens range from 6.5 to 10.9 mm cl in males, and from 8.0 to 12.5 mm cl in females.

Colour pattern. Body semitransparent greyish with pale brown to red-brown reticulation on abdomen and carapace, formed by interconnected chains of chromatophore groups; antennular and antennal flagella pale or strawyellow; chelipeds with ischium, merus and carpus brown with white spots and blotches; mesial face of major chela brown with paler areas on ventral and dorsal depression, and with numerous irregular whitish spots and blotches; distal palm as well as dorsal margins of pollex and dactylus olive-greenish; distal portion of dactylus and pollex pink; ventroproximal portion of palm often tinged with pale purplish; second to fifth pereiopods reddish-brown mixed with yellow and colourless areas near articulations; telson and uropods with brown reticulation and larger colourless areas, uropodal exopod and endopod with distal margin dark bluish; eggs reddish (Figs. 61, 62); young individuals with more obvious reticulation (Fig. 63C); some individuals darker or with fine spotting rather than reticulation (Fig. 63A, B; see below).

Type locality. Barahona, Dominican Republic .

Distribution. Florida (Indian River Lagoon, Miami area, Florida Keys, Dry Tortugas); Caribbean Sea: Cuba (Batabano Gulf), Dominican Republic (Boca Chica), Puerto Rico, British Virgin Islands (Guana), Venezuela, Panama (Isla Grande, Bocas del Toro), Belize, Mexico, Guadeloupe, St. Martin, Tobago, and several other localities ( Armstrong 1949; Chace 1972; Martínez-Iglesias et al. 1996; present study) (see also map in Fig. 70 ).

Ecology. Lower intertidal and shallow subtidal habitats, mainly on soft bottoms; known depth range 0.5–3 m; typically on sand flats with seagrass ( Thalassia ) and scattered coral ubble, conch shells, and rocks, often near mangroves; in burrows under large rocks or rubble pieces, also in old conch shells; in male-female pairs.

Remarks. Alpheus viridari is closely related to species of the A. armillatus complex and was used as outgroup terminal in the phylogenetic analysis of Mathews & Anker (2009). Unlike species of the A. armillatus complex, A. viridari does not have a distinct post-rostral plate, although the rostral carina subtly flattens posteriorly to the eyes ( Fig. 60A ). In addition, A. viridari can be distinguished from all species of the A. armillatus complex by the pres- and the more slender minor chela in both sexes ( Fig. 60L ) (see also Table 1). Alpheus viridari can also be distinguished from A. armillatus and its close relatives by its colour pattern (Figs. 61, 62), especially diagnostic being the pale orange-brown or brown-greenish reticulation of the carapace and abdomen and the white-spotted chelae (colour type NB 6 in Mathews & Anker 2009, fig. 2O).

In some specimens from Panama and St. Martin (Fig. 63A, B), the background pattern is a uniform fine spotting rather than reticulation. The specimens of the spotted colour morph are also darker and have less spots or blotches on the major chela compared to the reticulated colour morph. Morphologically, these two colour morphs seem to be identical, although a very thorough morphological / morphometric analysis has not yet been performed. In addition, the spotted and reticulated individuals of A. viridari may occur syntopically, for instance, on the Atlantic coast of St. Martin and in Bocas del Toro, Panama. A molecular analysis (COI, 16S) of the present material of A. viridari will be performed in the near future to investigate the genetic structure of this species and the possible presence of an additional cryptic taxon.

GenBank accession numbers. Florida: DQ682894 (16S), FJ528483 ( COI) [not deposited]; Panama: FJ528440 (16S), FJ528484 ( COI) [ OUMNH. ZC. 2011-06-041] .

except for G, by G. Paulay.

Figures

FIGURE 60. Alpheus viridari (Armstrong, 1949): A, Q, male from Guadeloupe, French Antilles [MNHN-Na 15642]; B–P, different male from Guadeloupe [OUMNH.ZC. 2011-06-044]; A, frontal region of carapace and frontal appendages, dorsal view; B, rostroorbital region of carapace, lateral view; C, same, dorsolateral view; D, tooth on mesioventral carina of first article of antennular peduncle, lateral view; E, antennal scaphocerite, dorsal view; F, major chela, lateral view; G, same, mesial view; H, major chela pollex, lateral view; I, major chela dactylus, lateral view; J, major cheliped, ischium, merus and caprus, mesial view; K, minor cheliped, lateral view; L, minor chela, mesial view; M, second pereiopod, lateral view; N, third pereiopod, lateral view; O, telson, dorsal view; P, uropod, dorsal view; Q, major cheliped, lateral view. Scale bars as indicated, fig. D drawn without scale.

FIGURE 70. Preliminary distribution maps for 11 western Atlantic species of the Alpheus armillatus H. Milne Edwards, 1837 complex (A. armillatus H. Milne Edwards, 1837; A. lancirostris Rankin, 1900; A. verrilli (Schmitt, 1924); A. angulosus McClure, 2002; A. amarillo sp. nov.; A. punctatus sp. nov.; A. tampensis sp. nov.; A. carlae sp. nov.; A. mathewsae sp. nov.; A. brasileiro sp. nov.; A. nuno sp. nov.) and A. viridari (Armstrong, 1949); individual locations refer to material reported in this study, verified literature records and in situ colour photographs.