Synalpheus obtusifrons Chace, 1972

Anker, Arthur, Pachelle, Paulo P. G., Grave, Sammy De & Hultgren, Kristin M., 2012, 3598, Zootaxa 3598 (1), pp. 1-96 : 61

Synalpheus obtusifrons Chace, 1972

Synalpheus obtusifrons Chace 1972: 99 , figs 37, 38; Lemaitre 1984: 426; Rodríguez 1986: 203, fig. 48; McClure 2005: 82, figs 47, 48.

Material examined. Aruba: 1 ov. female, OUMNH. ZC.2012-07-067, Baby Beach , coral rocks, 0.5–1 m, coll. A. Anker, 06.12.2003 [fcn 03-001] . Curaçao: 1 male, USNM 1187903 , Caracas Baai, in unidentified yellow “webby” sponge, 1–3 m, coll. K. Hultgren, 20.06.2008 [fcn CU08-4202] . Barbados: 1 ov. female, 1 male, USNM 1187907 , Breach Reef , in unidentified yellow “webby” sponge, 1–3 m, coll. K. Hultgren, 21.10.2008 [fcn BR08-6302 - 6303 ] .

Description. For description and illustrations see Chace (1972).

Size range. Males, 1.8–3.3 mm cl; females, 3.6–3.75 ( Chace 1972), female from Aruba slightly larger, at 3.9 mm cl.

Colour in life. Field notes from Aruba indicated “semitransparent pale greenish body, green eggs” (A. Anker, pers. obs.).

Type locality. Bahía de Espíritu Santo , Yucatan, Mexico .

Distribution. Western Atlantic: Bahamas [Cay Sal Bank]; Gulf of Mexico: Mexico [Campeche]; Caribbean Sea: Mexico’s Yucatan Peninsula [Bahía de Espíritu Santo, Bahía de la Ascensión], Venezuela [Los Roques Archipelago], Aruba, Curaçao, Barbados ( Chace 1972; Lemaitre 1984; Rodríguez 1986; McClure 2005; present study; see map in Fig. 52 ).

Ecology. Shallow reef and adjacent habitats; known depth range 1–14 m; in crevices of coral rocks and in an unidentified yellow webby sponge ( Chace 1972; Lemaitre 1984; present study).

Remarks. Synalpheus obtusifrons can be distinguished from all other species of Synalpheus by the combination of the following four features: (1) the minor cheliped without gambarelloid setae; (2) the stylocerite with a rounded tip overreaching the distal margin of the first article; (3) the frontal margin of the carapace with short, broadly rounded orbital hoods and a short triangular rostrum; and (4) the distal tooth on the major chela palm sharp and slightly descendent ( Chace 1972). This species appears to be uncommon, being known only from a few localities, and is herewith recorded from the former Netherlands Antilles for the first time.

Figures

FIGURE 52. Presently known geographic ranges of Synalpheus hoetjesi Hultgren, Macdonald & Duffy, 2010; S. idios (Ríos & Duffy, 2007); S. kensleyi (Ríos & Duffy, 2007); S. cf. longicarpus (Herrick, 1891); S. obtusifrons Chace, 1972; S. pandionis Coutière, 1909; S. parfaiti Coutière, 1898; S. pectiniger Coutière, 1909; S. rathbunae Coutière, 1909; S. regalis Duffy, 1996; S. sanctithomae Coutière, 1909; S. scaphoceris Coutière, 1910; S. senegambiensis Coutière, 1908; S. townsendi Coutière, 1909; S. ul (Ríos & Duffy, 2007) and S. yano (Ríos & Duffy, 2007).