Synalpheus antillensis Coutière, 1909,

Anker, Arthur, Pachelle, Paulo P. G., Grave, Sammy De & Hultgren, Kristin M., 2012, 3598, Zootaxa 3598 (1), pp. 1-96 : 16-18

Synalpheus antillensis Coutière, 1909 stat. nov.

( Figs 9 , 10a–c )

Synalpheus minus form antillensis Coutière 1909: 46 , fig. 27.

Synalpheus minus antillensis — Chace 1956: 148; Ray 1974: 153.

Synalpheus minus — Christoffersen 1979: 350 (partim), fig. 28 [not S. minus (Say, 1818) ].

? Synalpheus minus — Chace 1972: 95 (partim) [not S. minus (Say, 1818) ].

Material examined. US Virgin Islands: 2 males, syntypes, USNM 38397 , off St. Thomas , sta. 6079, 20–23 fathoms, M. Steamer Fish Hawk, 06.02.1899 . Dominican Republic: 1 female, MNHN-IU-2010-4108, Bayahibe , coral rocks, 1–2 m, coll. A. Anker, 02- 03.01.2005 [fcn 05-036*] . Mexico: 1 male, UNAM-Sisal, Mahaual , shallow rubble field with seagrass, in crevices of coral rocks, 0.5–1 m, coll. A. Anker, J. Duarte-Gutiérrez, 06.07.2010 [MAH-003] . Panama: 1 male, 1 female, OUMNH. ZC.2012-07-038 , Isla Grande, Playa de la Punta, coral rocks, 1–2 m, coll. A. Anker, C. Hurt, 06.10.2005 [fcn 05-055*]; 1 male, 1 female, RMNH D54856, La Guaira , coral rocks, 1–2 m, coll. A. Anker, J.A. Baeza, 04.08.2007 [fcn 07-222*]; 1 female, UP , Isla Grande, NE coast, 0.5–1 m, coralline algae and coral rocks, coll. A. Anker, J.A. Vera Caripe, J. Luque, 16.09.2007 [fcn 07- 246*] . Honduras: 1 male, OUMNH. ZC.2012-20-064, Utila, reef in front of Coral View Resort, 16º05.326’ N 086º54.652’ W, 10 m, in Ircinia sp. , coll. S. De Grave, A. Anker, 28.06.2007 [fcn H4]; 2 males, 1 ov. female, OUMNH. ZC.2012-20-058, Utila , small bay between Utila town and Coral View Resort, 16º05.458’ N 086º54.533’ W, ~ 1 m, coral rubble, A. Anker, S. De Grave, 03.07.2007 [fcn H80*, H91*, H98*] . St. Martin: 1 male, FLMNH UF 32399 , Réserve Naturelle de Saint-Martin, sta. 54, Baie de l'Embouchure , Îlet de L'embouchure, in crevices of coral rubble and coralline algae, 0.5–1 m, coll. J.F. Maréchal, A. Anker, 22.04.2012 [fcn BSTM-1422*] . Trinidad & Tobago: 1 specimen (sex not determined), FLMNH UF 10944 , Tobago, Canoe Bay , 11.1402° -60.7991°, coll. H.C. Liu, 03.02.2005 . Brazil: 1 immature male, UFC 442 , Ceará, locality not specified (“litoral do estado do Ceará ”), 35–40 m, coll. “Barco SWJ”, 24.11.1972; 1 female (dissected), MNRJ 17893 , Atol das Rocas, Canal da Barretão , in unidentified sponge, ~ 5 m, coll. F.B. Pitombo, R. Barroso, 26.12.2000; 1 male, MNRJ 23331 , Atol das Rocas, Piscina das Rocas, sta. P8, calcareous algae, coll. P.S. Young, P.C. Paiva, A.A. Aguiar, 07.10.2000; 1 male, OUMNH. ZC.2012-07-144, Alagoas, Maceió, Ponta Verde, deep tide pool on partly exposed reef, in rubble crevices, 0.5–1 m (at low tide), coll. A. Anker, P. Pachelle, 02.08.2012 [fcn 12-261]; 1 male, MZUSP 25337 , Espírito Santo, Supel (?), coll. unknown, 05.09.1994; 1 immature male, MZUSP 25338 , Rio de Janeiro, Baia de Sepetiba, sta. MBR, Q P3, 0.5 m, coll. J. Vianna da Silva, 12.2005; 1 male, MZUSP 22307 , São Paulo, São Sebastião, Praia Boissucanga, coll. M.L. Christoffersen, 17.02.1977 .

Comparative material. Synalpheus minus (Say, 1818) : USA: 1 male, FLMNH-UF 9350 , off southern Florida, 25º38.15’N 81º58.74’W, grass bottom, 30’ otter trawl, ~ 9 m, coll. F. Michonneau et al., 15.03.2007 [fcn FRM-467, GHB-2007-15] ; 1 male, USNM 41655 , Florida, Marco, 1–2 fathoms, among sponges [specimen identified by H.

Diagnosis. Rostrum subequal to orbital teeth in length and width at base, subtriangular, more slender distally, tip acute; orbital teeth triangular, acute or subacute distally; notches between orbital teeth and rostrum deep, Ushaped. First abdominal somite in males acutely produced posteroventrally. Telson broad, tapering posteriorly, anterior margin less than 1.5 times as long as posterior margin; dorsal surface with two pairs of small spiniform second article as long as to slightly longer than wide; stylocerite not reaching distal of second article. Antenna with basicerite armed with small, subacute, distodorsal tooth and strong ventrolateral tooth, latter not reaching tip of stylocerite; scaphocerite with narrow blade, distolateral tooth reaching end of antennular peduncle, but not reaching end of carpocerite. Third maxilliped with crown of four to five spiniform setae on tip of ultimate article. Major chela with palm approximately 2.5–3.1 times as long as fingers; distal tooth projecting, not bulbous, with acute or subacute point; distolateral surface of palm with two blunt or subacute tubercles. Second pereiopod with carpus five-articulated, first article longer than remainig articles combined. Third pereiopod with merus slender, about 3.5–4 times as long as maximum width; propodus with about seven spiniform setae on ventral margin (including distal pair); dactylus biunguiculate, proximal unguis shorter and subparallel to distal unguis, both about equal in width. Uropodal exopod with one distolateral tooth adjacent to slender spiniform seta ( Fig. 6 ).

Description. For description and illustrations see Coutière (1909), as S. minus form antillensis ; illustrations of the Atol das Rocas material of S. antillensis are provided in Fig. 9 .

Size range. Males, 3.2–5.0 mm cl; females, 3.8–5.0 mm cl.

Colour in life. Semi-translucent pale greenish, with distinct dark red-purple bands between the eyes (possibly also on eyestalks); major chela distally very intense pink; minor chela also pink distally; walking legs with reddish or pinkish chromatophores; ovaries and freshly-laid eggs olive-green ( Fig. 10a–c ).

Type locality. St. Thomas , US Virgin Islands .

Distribution. Western Atlantic: Gulf of Mexico: off Texas [Flower Garden Banks]; Caribbean Sea: Mexico’s Yucatan Peninsula [Mahaual], Honduras [Utila], US Virgin Islands [St. Thomas], Panama [ Isla Grande, Bocas del Toro], Dominican Republic [Bayahibe], Venezuela [ Isla Margarita, Los Roques Archipelago], St. Martin, Trinidad & Tobago; Brazil: Ceará, Atol das Rocas, Alagoas, Bahia, Espírito Santo, Rio de Janeiro, São Paulo ( Coutière 1909; Chace 1956; Ray 1974; present study; see map in Fig. 51 ).

Ecology. Shallow reef and similar hard-bottom habitats; depth range 1–42 m; in crevices of coral rocks lined with coralline algae, sponges, and other epibionts, rarely in or among sponges (e.g., Ircinia spp. ); typically in heterosexual pairs.

Remarks. Synalpheus antillensis was originally described by Coutière (1909) as a “form” of S. minus (Say, 1818) and in all subsequent studies listed either as a subspecies of S. minus ( Chace 1956) or as its junior synonym ( Christoffersen 1979). However, very clear differences between S. minus and S. antillensis , especially in the proportions of the antennular peduncle and scaphocerite, colour pattern, and body size, leave no doubt that S. antillensis is a valid species.

Synalpheus antillensis can be distinguished from S. minus by the second article of the antennular peduncles being only slightly longer than wide (vs. much longer than wide in S. minus ); and the longer and sharper orbital teeth (shorter and blunter in S. minus ) (cf. Coutière 1909, Figs 25a , 27a ; see also Fig. 9a ). In addition, the two species differ greatly in body size: S. minus is one of the largest species of Synalpheus in the western Atlantic, with the carapace length reaching 12–13 mm and tl over 30 mm in the largest specimens in the USNM and FLMNH material, whereas the maximum total length known for S. antillensis is about 15 mm ( Coutière 1909; present material). Furthermore, S. antillensis can be distinguished from S. minus (and all other western Atlantic species of Synalpheus ) by its diagnostic and very striking colour pattern ( Fig. 10a–c ). In fact, in both S. minus and S. antillensis , the major and minor chelae are distally pink, but only in S. antillensis is the colour a very intense, uniform, purplish pink (Fig. 7a–c), contrasting to an orange pink marbled with white pattern in S. minus ( Fig. 10d, e ).

The taxonomic status of S. minus form bahiensis Coutière, 1909 from Brazil and S. minus var. somersi Verrill, 1922 from Bermuda will be re-examined elsewhere (see below), but both forms are morphologically clearly different from S. antillensis (cf. Coutière 1909; Verrill 1922). Christoffersen’s (1979) material of S. minus from Brazil contains at least two species, most likely S. minus (or S. m. bahiensis) and S. antillensis . Christoffersen’s figures of a specimen from Bahia ( Christoffersen 1979: fig. 28) and his description of the colour pattern of some Brazilian specimens (sparsely dotted with green chromatophores, with bright pink tips of chelae, cf. Fig. 10a–c ) clearly correspond to S. antillensis . In Brazil, S. antillensis appears to be relatively widespread, ranging from Atol das Rocas and Ceará to São Paulo.

It is important to note that many of the previous records of S. minus from the western Atlantic, especially from the Caribbean Sea, may actually refer to the closely related S. brevicarpus s. lat. and vice versa. The complex

Figures

FIGURE 6. Synalpheus agelas Pequegnat & Heard, 1979: ovigerous female from St. Martin (FLMNH UF 32276) in dorsal (a) and lateral (b) views. Photographs by A. Anker.

FIGURE 9. Synalpheus antillensis Coutière, 1909: female from Atol das Rocas, Brazil (MNRJ 17893); a, frontal region, dorsal; b, major chela, mesial; c, same, lateral; d, major cheliped, coxa to carpus, mesial; e, minor cheliped, lateral; f, minor chela, lateral; g, second pereiopod, lateral; h, third pereiopod, lateral; i, uropod, dorsal; j, telson, dorsal. Scale bars = 1 mm.

FIGURE 10. Synalpheus antillensis Coutière, 1909 (a–c) contrasted to Synalpheus minus (Say, 1818) (d, e); a, male from

FIGURE 25. Synalpheus elizabethae (Ríos & Duffy, 2007): a, ovigerous female (queen) and two colony members from Bocas del Toro, Panama (specimens not deposited); b, colony member from Isla Grande, Panama (MNHN-IU-2010-4129). Photographs: a, by E. Tóth; b, by A. Anker.

FIGURE 27. Synalpheus fritzmuelleri Coutière, 1909: a, male (above) and ovigerous female (below) from Isla Grande, Panama (MNHN-IU-2010-4131); b, male from Bocas del Toro, Panama (OUMNH.ZC.2012-07-096), infested by a bopyrid isopod; c, male from Marathon, Florida Keys, USA (RMNH D54839); d, female from Fort Pierce, Florida, USA (OUMNH.ZC.2012-07-098); e, f, ovigerous female from Bayahibe, Dominican Republic (RMNH D54838). Photographs: a, b, e, f, by A. Anker; c, by A.L. Rhyne, d, by J.A. Baeza.

FIGURE 51. Presently known geographic ranges of Synalpheus africanus Crosnier & Forest, 1965; S. cf. africanus (eastern and western Atlantic); S. agelas Pequegnat & Heard, 1979; S. anasimus Chace, 1972; S. antillensis Coutière, 1909; S. apioceros Coutière, 1909; S. bocas Anker & Tóth, 2008; S. bousfieldi Chace, 1972; S. brooksi Coutière, 1909; S. carpenteri Macdonald & Duffy, 2006; S. chacei Duffy, 1998; S. congoensis Crosnier & Forest, 1965; S. dardeaui (Ríos & Duffy, 2007); S. dominicensis Armstrong, 1949; S. elizabethae (Ríos & Duffy, 2007); S. filidigitus Armstrong, 1949; S. fritzmuelleri Coutière, 1909; S. goodei