Alpheus nuttingi ( Schmitt, 1924 )

Anker, Arthur, Hurt, Carla & Knowlton, Nancy, 2007, Revision of the Alpheus nuttingi (Schmitt) species complex (Crustacea: Decapoda: Alpheidae), with description of a new species from the tropical eastern Pacific, Zootaxa 1577 (1), pp. 41-60 : 44-47

Alpheus nuttingi ( Schmitt, 1924)

Figs. 1 , 5A , 6A , 7A–C , 8A

Crangon nuttingi Schmitt, 1924: 78 , pl. 2, figs. 4–6

Alpheus nuttingi – Hendrix, 1971: 111, pls. 14, 15; Chace, 1972: 68; Christoffersen, 1979: 304; Christoffersen, 1980: 92, figs. 21–23; Santos, 1981: 342, figs. 17f, g, 18a, b, f; Abele & Kim, 1986: 199, 214, 215, figs. e, h; Knowlton & Mills, 1992: 2; Hernández-Aguilera et al., 1996: 33; Martínez-Iglesias et al., 1997: 425; Christoffersen, 1998: 360; Santos & Coelho, 1998: 76, fig. 16; McClure, 2005: 147, fig. 18.

Alpheus nutting (lap. cal.) – Spivak, 1997: 72.

Not Alpheus nuttingi var.? – Schmitt, 1936: 368 (= A. cf. bouvieri A. Milne-Edwards, 1878 )

Alpheus heterochaelis (not Say 1818) – Smith, 1871: 23 (part.); Rathbun, 1900: 152 (part.); Luederwaldt, 1919: 429 (part.) (see Christoffersen, 1984).

Crangon heterochaelis (not Say, 1818) – Schmitt, 1939: 28 (part.) (see Christoffersen, 1984).

Material examined.— Panama: 1 male, USNM 1100678 , Bocas del Toro, Isla Carenero, near Bucaneer, under rocks on sand/silt, depth: 0.5– 1 m, coll. A. Anker, 25 Oct 2005 [fcn 05-143] ; 1 female, USNM 1100679 , same collection data as previous specimen [fcn 05-138] ; 1 male, USNM 1100680 , Bocas del Toro, Hospital Point, under rocks on sand/silt, depth: 0.5– 1 m, coll. A. Anker, 16 Oct 2005 [fcn 05-140]; 1 ovig. female, MNHN-Na 16364, Bocas del Toro, Isla Colon , between Big Creek and Playa Bluff, from crevices in coral rocks, depth: 1–2 m, coll. A, Anker, 18 Oct 2005 [fcn 05-142] ; 2 males, USNM 1100682 , Bocas del Toro, Isla Colon, Bocas del Drago , from coral rocks, depth: 0.5– 1 m, coll. A. Anker, 20 Oct 2005 [fcn 05-141] ; 1 male, USNM 1100681 , Coco Solo, near Colón, under rocks, coll. N. Knowlton lab, 22 Feb 1995 [fcn B331, C- 1239] . Costa Rica: 1 male, MNHN-Na 16365, Cahuita, Puerto Vargas, under rocks and coral rubble, among seagrass roots, depth: 0.5– 1 m, coll. A. Anker, 26–27 Nov 2005 [fcn 05-144] . Aruba: 1 male, 1 female, MNHN-Na 16366, southern coast east of international airport, Pos Chiquito, from coral rocks, depth: 0.5– 1 m, coll. A. Anker, 7–8 Dec 2003 [fcn 03-013] .

Description.—For complete description see Schmitt (1924) and Hendrix (1971). An adult male from Panama is illustrated in Fig. 1 for comparison with the below-described A. millsae , n. sp.

Size.—The largest examined male is 12.7 mm CL and 36.8 mm TL. Hendrix (1971) gave the size range for Florida specimens as 5.5–10.0 mm CL for males and 6.0–9.16 mm CL for females.

Color.—Body greenish (combination of reddish and bluish chromatophores) speckled with numerous pale yellow or greenish dots, some interconnected, forming chains and small reticulations; flanks of carapace dull greenish to whitish; legs reddish with some spots and white patches marking articulations; third and fourth abdominal somite occasionally with a pair of minute dark-brown dorsolateral spots; fifth somite occasionally with one minute brown mediodorsal spot; major and minor chelae mesially greenish-brown with numerous whitish spots and patches, many of them interconnected, especially on distal half of palm and fingers; pale orange or yellow areas marking palmar depressions; dactylus of major chela pinkish-white distally; antennular and antennal flagella pale blue ( Fig. 7A, B ); ovigerous females with yellow-orange eggs ( Fig. 8A ); young individuals paler, more reticulated ( Fig. 7C ). A similar color description was provided by Hendrix (1971).

Type locality.— Pelican Island , Barbados ( Schmitt, 1924) .

Distribution.—Western Atlantic: from southern Florida ( Abele & Kim, 1986) and southwestern Gulf of Mexico ( McClure, 2005) throughout Caribbean Sea ( Chace, 1972) to Santa Catarina, southern Brazil ( Christoffersen, 1998). Brazilian specimens are genetically distinct from the Caribbean specimens (Williams et al., 2001; see also below) despite having the same color pattern (A. Anker, pers. obs., based on color photographs by E. Mossolin).

Ecology.— Alpheus nuttingi is a very common Alpheus species in the Caribbean region and along the Brazilian coast. It occurs mostly on sandy bottoms with abundant coral rubble and rocks, often near Thalassia beds; in crevices of coral rocks; among sandy reefs of sabellariid polychaetes; in clumps of Halimeda and similar habitats in depths ranging from the intertidal to about 5 m ( Hendrix, 1971; Chace, 1972; Christoffersen, 1998).

Remarks.— Alpheus nuttingi differs from the closely related A. millsae , n. sp. (see description below) mainly by the shorter rostral carina ( Fig. 1C ); the larger and more robust plunger of the dactylus of the major chela ( Fig. 5A ); the broader dorsal notch on the palm of the major chela ( Fig. 5A ); the relatively thicker fingers of the minor chela ( Fig. 6A ); and by the color pattern, especially by the pale dots being mostly chained or interconnected (vs. isolated in A. millsae , n. sp., cf. Fig. 7 ) (see also Table 1). It differs from A. galapagensis by the absence of a spine on the ischium of the third pereiopod ( Fig. 1N ), which is always present in A. galapagensis (see Kim & Abele, 1988, fig. 30j), and by the color pattern, especially the blue antennal and antennular flagella (orange in A. galapagensis , cf. Fig. 7 ) (see also Table 1).

The presence or absence of small dark (blackish or dark brown) spots on the third (two dorsolateral), fifth (one median) and occasionally fifth (one median) abdominal somites is shown here not to be a reliable character. These spots are always present in A. millsae , n. sp. ( Fig. 7G, H ) and are usually absent in A. nuttingi ( Fig. 7A, C ); however, at least two examined specimens of the latter species have feebly marked brown spots on the abdomen ( Fig. 7B ), thus making this feature too ambiguous to be used for species discrimination. The color of freshly-laid eggs (orange in one photographed female of A. nuttingi , cf. Fig. 8A ), if shown to be constant, may also separate A. nuttingi from the two eastern Pacific species, in particular from A. galapagensis , in which the eggs are bright green (cf. Fig. 8B ).

The shape of the tooth on the mesioventral carina of the first segment of the antennular peduncle appears to be variable in A. nuttingi and other species of the complex (see below). This tooth usually bears an acute or subacute point ( Fig. 1D ), but is bluntly subtriangular in some specimens, resembling the tooth in A. galapagensis illustrated by Kim & Abele (1988, fig. 30c). The minor chela is more slender in younger males and females compared to larger adult males.

A minor detail that Hendrix (1971) overlooked in his otherwise very detailed description of A. nuttingi is the presence of spinules on the distal margin of the telson and uropodal endopod ( Fig. 1R ); these spinules are also present in A. galapagensis ( Kim & Abele, 1988, fig. 30l) and A. millsae , n. sp. ( Fig. 4R , see below).

GenBank number.— COI 5’ EF092281 (fcn 05-127), EF092282 (fcn 06-417); COI 3’ AF309922 (fcn 98-330) AF309921 (fcn 98-282), AF309000 (fcn 98-282) .

Figures

FIGURE 1. Alpheus nuttingi (Schmitt, 1924), male specimen from Colón, Panama (USNM 1100681): A, frontal region, dorsal view; B, same, lateral view; C, orbital hoods and rostrum, dorsal view; D, tooth on ventromesial carina of first segment of antennular peduncle, lateral view; E, scaphocerite of antenna, dorsal view; F, third maxilliped, lateral view; G, major cheliped, mesial view; H, same, lateral view (chela slightly dorsolateral); I, same, chela, lateral view; J, minor cheliped, mesial view; K, same, lateral view; L, chela with opened fingers, lateral view; M, second pereiopod, lateral view; N, third pereiopod, lateral view; O, same, propodus and dactylus; P, fifth pereiopod, lateral view; Q, second pleopod, appendix masculina and appendix interna, mesial view; R, left uropod and telson, dorsal view. Scale bars: 5 mm (AFMNR, BCEO, GHJK, ILP), 1 mm (DQ).

FIGURE 4. Alpheus millsae, n. sp., male paratype (USNM 1100688) (A–R) and female paratype (USNM 1100689) (S) from Río Mar, Panama: A, frontal region, dorsal view; B, same, lateral view; C, orbital hoods and rostrum, dorsal view; D, tooth on ventromesial carina of first segment of antennular peduncle, lateral view; E, scaphocerite of antenna, dorsal view; F, third maxilliped, lateral view; G, same, detail of coxa and arthrobranch; H, major cheliped, mesial view; I, same, lateral view (chela slightly dorsolateral); J, same, chela, lateral view; K, minor cheliped, mesial view; L, same, lateral view; M, chela with opened fingers, lateral view; N, second pereiopod, lateral view; O, third pereiopod, lateral view; P, same, propodus and dactylus; Q, second pleopod, appendix masculina and appendix interna, mesial view; R, left uropod and telson, dorsal view; S, female major chela, lateral view. Scale bars: 5 mm (AFNOR, BJMS, CEGP, IH, LK), 1 mm (DQ).

FIGURE 5. Major chelae of large male specimens of Alpheus nuttingi (Schmitt, 1924) (A), Alpheus galapagensis Sivertsen, 1933 (B) and Alpheus millsae, n. sp. (C), showing differences in the shape of the dactylus plunger and dorsal notch of the palm (see arrows); A, male from Cahuita, Costa Rica (MNHN-Na 16365); B, male from Las Perlas, Panama (USNM 1100683); C, male from Casco Viejo, Panama (holotype, USNM 1100686).

FIGURE 6. Minor chela of large male specimens of Alpheus nuttingi (Schmitt, 1924) (A), Alpheus galapagensis Sivertsen, 1933 (B) and Alpheus millsae, n. sp. (C) showing slight differences in the relative thickness of the fingers; A, male from Cahuita, Costa Rica (MNHN-Na 16365); B, male from Las Perlas, Panama (USNM 1100683); C, male from Casco Viejo, Panama (holotype, USNM 1100686).

FIGURE 7. Color patterns, in dorsal view, of Alpheus nuttingi (Schmitt, 1924) (A-C), Alpheus galapagensis Sivertsen, 1933 (D–F) and Alpheus millsae, n. sp. (G, H): A, large adult male from Cahuita, Costa Rica (MNHN-Na 16365); B, adult male from Bocas del Toro, Panama (USNM 1100678); C, subadult female from Bocas del Toro, Panama (USNM 1100679); D, large adult male from Punta Culebra, Panama (OUMNH-ZC 2006-10-0005); E, adult male from Las Perlas, Panama (USNM 1100683); F, ovigerous female from Río Mar, Panama (MNHN-Na 16368); G, adult male from Casco Viejo, Panama (paratype, MNHN-Na 16369); H, large adult male from Casco Viejo (holotype, USNM 1100686).

FIGURE 8. Color patterns, in lateral view, of ovigerous females of Alpheus nuttingi (Schmitt, 1924) (A), Alpheus galapagensis Sivertsen, 1933 (B), and Alpheus millsae, n. sp. (C), showing color of eggs: A, specimen from Bocas del Toro, Panama (MNHN-Na 16364); B, specimen from Río Mar, Panama (MNHN-Na 16368); C, specimen from Casco Viejo, Panama (paratype, MNHN-Na 16369). Note that in the female of A. millsae, n. sp., eggs (see insert) started to develop and so their color cannot be used for direct comparison with A. nuttingi and A. galapagensis.