Alpheus formosus Gibbes, 1850

Anker, Arthur, Tavares, Marcos & Mendonça, Joel B., 2016, Alpheid shrimps (Decapoda: Caridea) of the Trindade & Martin Vaz Archipelago, off Brazil, with new records, description of a new species of Synalpheus and remarks on zoogeographical patterns in the oceanic islands of the tropical southern Atlantic, Zootaxa 4138 (1), pp. 1-58 : 20-22

Alpheus formosus Gibbes, 1850

( Fig. 5 )

Alpheus formosus Gibbes 1850: 196 ; Christoffersen 1979: 314 (partim); Anker et al. 2008d: 5 , figs. 1–4, 7c–e; Alves et al. 2008: 49; Souza et al. 2011: 46; Santos et al. 2012: 151, fig. 3E; Soledade & Almeida 2013: 100, fig. 5D; Soledade et al. 2015: 58, fig. 3D; Cunha et al. 2015: 48.

[for a more complete synonymy, especially prior to 2008, see Anker et al. (2008d)]

Material examined. Brazil: 1 female, MZUSP 33327, Trindade Island, Enseada Orelhas, 20°29’40.2”S – 29°20’32.9”W, depth: 6.9 m, coll. J.B. Mendonça, 12.xi.2014; 1 female, MZUSP 31006, Trindade Island, Paredão, 20°31’36.9”S – 29°18’14.3”W, depth: 19 m, coll. J.B. Mendonça, 19.vi.2014; 1 male, MZUSP 31108, Trindade Island, Enseada da Cachoeira, Farrilhões, 20°31’22.4”S – 29°19’52.0”W, depth: 10.4 m, coll. J.B. Mendonça, 09.vii.2013; 1 female, MZUSP 34135, Trindade Island, Praia do Lixo, 20°31’29.8”S – 29°19’43.9”W, depth: 13.7 m, coll. J.B. Mendonça, 25.x.2014; 1 ovig. female, MZUSP 33392, Trindade Island, large underwater boulder at Praia do Príncipe, 20°31’24.3”S – 29°18’46.5”W, depth: 14.4 m, coll. J.B. Mendonça, 23.iv.2014; 1 male, MZUSP 33260, Trindade Island, Ilha da Racha, 20°30’26.5”S – 29°20’40.0”W, depth: 25 m, coll. J.B. Mendonça, 12.xi.2014; 1 ovig. female, MZUSP 33276, Trindade Island, Enseada dos Portugueses, Farol, 20°29’52.3”S – 29°19’15.6”W, depth: 13.2 m, coll. J.B. Mendonça, 08.v.2014; 1 ovig. female, MZUSP 33267, Trindade Island, Enseada dos Portugueses, SECON 20°30’20.9”S – 29°18’43.7”W, depth: 10 m, coll. J.B. Mendonça, 14.v.2014; 1 ovig. female, MZUSP 30048, Trindade Island, Enseada dos Portugueses, SECON, 20°30’20.9”S – 29°18’43.7”W, depth: 11.6 m, coll. J.B. Mendonça, 18.vii.2012; 1 ovig. female, 1 male, MZUSP 33340, Trindade Island, Enseada dos Portugueses, SECON, 20°30’18.7”S – 29°18’31.6”W, depth: 15.6 m, coll. J.B. Mendonça, 31.iv.2014; 1 ovig. female, 1 male, MZUSP 33294, Trindade Island, Enseada dos Portugueses, Ponta da Calheta, 20°30’18.7”S – 29°18’31.6”W, depth: 15.6 m, coll. J.B. Mendonça, 20.v.2014; 1 male, MZUSP 33359, Trindade Island, Enseada dos Portugueses, Ponta da Calheta, 20°30’’18.7””S– 29°18’31.6”W, depth: 15.8 m, coll. J.B. Mendonça, 22.x.2014; 2 males, MZUSP 30355, Trindade Island, Praia do Andrada, 20°30’45.7”S – 29°18’21.9”W, tide pool, depth: 0.5 m, coll. J.B. Mendonça, 21.vii.2013; 1 male, MZUSP 34149, Martin Vaz Island, 20°28’28.4”S – 28°51’24.5”W, depth: 21.4 m, coll. J.B. Mendonça, 21.vi.2015. Size of largest male: cl 7.6 mm ( MZUSP 33294); largest female: cl 10.5 mm ( MZUSP 33267). Numerous additional specimens (not listed above) are deposited in MZUSP.

Description. Anker et al. (2008d) provided a detailed redescription and numerous illustrations of A. formosus , including colour photographs; for colour photographs of the Brazilian material see Santos et al. (2012), Soledade & Almeida (2013) and Soledade et al. (2015) (see also Fig. 5 ).

Distribution. Western Atlantic: Gulf of Mexico; Florida; throughout Caribbean Sea; Bermuda; Brazil: Ceará to Santa Catarina, Abrolhos Archipelago, Fernando de Noronha, Atol das Rocas , Trindade and Martin Vaz Archipelago ( Anker et al. 2008d and references therein; Soledade & Almeida 2013 and references therein; Soledade et al. 2015; Cunha et al. 2015; present study).

Ecology. Diverse shallow habitats, including coral reefs, intertidal fossilised reef flats, seagrass beds with abundant rubble, typically in crevices of coral rubble and under coral rocks, occasionally in sponges, intertidal to at least 40 m.

Remarks. Alpheus formosus is one of the most common and conspicuous snapping shrimps ( Fig. 5 ) in the western Atlantic, including Brazil where it is known from numerous localities along almost the entire continental coast, as well as from the oceanic islands of Fernando de Noronha, Atol das Rocas , and Trindade and Martin Vaz ( Anker et al. 2008d; Soledade & Almeida 2013; present study). The abundance of material from Trindade Island shows that A. formosus is fairly common in the shallow subtidal habitats in the studied area.

Figures

FIGURE 5. Alpheus formosus Gibbes, 1850, female from Enseada dos Portugueses, Trindade Island, Brazil (MZUSP 33276): A — dorsal view; B — lateral view. Photographs by J. B. Mendonça.