Alpheus galapagensis Sivertsen, 1933

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 : 47-50

Alpheus galapagensis Sivertsen, 1933

Figs. 2 , 5B , 6B , 7D–F , 8B

Alpheus strenuus var. galapagensis Sivertsen, 1933: 3 , pl. 1, figs. 1–5; Banner & Banner, 1982: 228.

Alpheus galapagensis — Kim & Abele, 1988: 102, fig. 43; Wicksten & Hendrickx, 1992: 5; McClure & Wicksten, 2000: 968, fig. 3; Hickman & Zimmerman, 2000: 36; Wicksten & Hendrickx, 2003: 64.

Alpheus canalis Kim & Abele, 1988: 72 , fig. 30; Villalobos Hiriart et al., 1989: 20; Ríos, 1989: 105, pl. 20; Ríos, 1992: 4; Flores-Hernández, 1991: 106; Lemaitre & Alvarez-Leon, 1992: 42; Wicksten & Hendrickx, 1992: 4; Hernández Aguilera & Martínez Guzman, 1992: 4; Hendrickx, 1992: 9; Hendrickx, 1993a: 306; Hendrickx, 1993b: 6; Hendrickx, 1995: 432; Camacho, 1996: 80; Vargas & Cortés, 1999: 899; Villalobos, 2000: 43, fig. 21; McClure & Wicksten, 2000: 968, fig. 3 (part., not fig. 3H).

Alpheus canalis sp-a— Knowlton & Mills, 1992: 2.

Alpheus canalis sp. a— Knowlton et al., 1993: 1630.

Alpheus canalis “orange” – Williams et al., 2001: 377.

Alpheus canalis “orange antennae” —Williams et al., 2001: 385.

Alpheus cryptodentatus Christoffersen & Ramos, 1988: 61 , figs. 1, 2.

Material examined.— Panama: 1 male, USNM 1100683 , Las Perlas, small island facing Contadora , rocky intertidal, under rocks on coarse sand, extreme low tide, coll. A. Anker, C. Hurt, E. Gómez, J. Jara and E. Tóth, 31 Mar 2006 [fcn 06-382] ; 1 male, 1 ovig. female, MNHN-Na 16367, Amador, Punta Culebra , rocky intertidal, under large rocks on sand, low tide, coll. A. Anker and C. Hurt, 2 Mar 2006 [fcn 06-284] ; 1 male, USNM 1100684 , same collection data as previous specimen [fcn 06-301]; 1 ovig. female, MNHN-Na 16367, same collection data as previous specimen [fcn 06-286] ; 1 male, 1 ovig. female, MNHN-Na 16368, Río Mar , intertidal, under rocks on silt/sand, low tide, coll. A. Anker, C. Hurt, J. Jara and E. Gómez, 3 Mar 2006 [fcn 06-298]; 1 ovig. female, USNM 1100685 , same collection data as previous specimen [fcn 06-256] ; 1 male, OUMNH-ZC 2006-10 - 0005 , Pacific coast of Panama near Panama City, rocky intertidal, coll. J. Jara, Jan 2006 [fcn 06-285] ; 1 female, UP, Amador Causeway, Isla Naos, Punta Culebra , under rocks at low tide, coll. A. Anker and I. Marin, 17 Apr 2004 [fcn 07-123] . Costa Rica: 1 male, 1 ovig. female, MNHN-Na 16384, Punta Morales, Playa Blanca , rocky intertidal, under oyster-covered rocks on coarse sand, low tide, coll. A. Anker, 22 Nov 2005 [fcn 05-145] .

Description.—For complete description see Sivertsen (1933), Kim & Abele (1988, as A. canalis ), Christoffersen & Ramos (1988, as A. cryptodentatus ) and McClure & Wicksten (2000).

Size.—The largest examined male from Panama (fcn 06-284) is 13.2 mm CL and 40.0 mm TL. Kim & Abele (1988) gave the size range for their specimens as following: males, 5.8–15.1 mm CL; females, 5.2–14.1 mm CL; ovigerous females, 6.1–15.0 mm CL.

Color.—Body greenish (combination of reddish and bluish chromatophores) speckled with numerous pale yellow dots or small yellowish spots, most of them isolated and not interconnecting; flanks of carapace dull greenish or whitish; legs reddish with some spots and white patches marking articulations; third and fourth abdominal somite usually with a pair of minute dark dorsolateral spots; fifth somite usually with one minute brown mediodorsal spot; major and minor chelae mesially greenish-brown with numerous whitish or pale bluish spots and dots, most isolated, not interconnecting; large yellow areas marking palmar depressions in larger specimens; dactylus of major chela pinkish distally; antennular and antennal flagella pale orange ( Fig. 2 , 7D–F ); ovigerous females with bright green eggs ( Fig. 8B ). A similar color description was provided by Christoffersen & Ramos (1988, as A. cryptodentatus ); a color photograph of a specimen from Galapagos was published by Hickman & Zimmerman (2000).

Type locality.—Floreana, Galapagos ( Sivertsen, 1933).

Distribution.—Eastern Pacific: from central Gulf of California through western Mexico, El Salvador, Costa Rica and Panama to Colombia and Galapagos ( Sivertsen, 1933; Kim & Abele, 1988; Christoffersen & Ramos, 1988; McClure & Wicksten, 2000; Villalobos, 2000; Wicksten & Hendrickx, 2003).

Ecology.— Alpheus galapagensis is a common snapping shrimp on the rocky and mixed rocky-sandy intertidal of the tropical eastern Pacific. It occurs on sand, mud, silt and rock bottoms, under rocks and rubble, in tidal lava pools, occasionally also in crevices of rocks and corals ( Villalobos, 2000; Wicksten & Hendrickx, 2003; present study). The depth range of this species extends from the mid-intertidal to about 15 m, exceptionally as deep as 37 m ( Villalobos, 2000). Some specimens were found under rocks together with fire worms ( Amphinomidae ), a facultative, protective association that is also observed in some other shallow water Alpheus species throughout the world (A. Anker, pers. obs.).

Remarks.— Alpheus galapagensis may be easily distinguished from both A. nuttingi and A. millsae , n. sp. (see description below) by the presence of a small spine on the ischium of the third pereiopod (see Kim & Abele, 1988, fig. 30j), and in life by the less densely spaced, usually rounded spots on the mesial face of the major claw (vs. more densely spaced, irregularly shaped and often interconnecting in the other two species, cf. Fig. 7 ), and the orange antennal and antennular flagella (vs. blue in the other two species, cf. Fig. 7 ) (see also Table 1). Like in A. nuttingi , the shape of the tooth on the mesioventral carina of the first segment of the antennular peduncle appears to be variable in A. galapagensis ; it may be blunt (cf. Kim & Abele, 1988, fig. 30c) or bear a minute acute point, as in some of the present specimens. The color of freshly-laid eggs (green in one photographed female of A. galapagensis , cf. Fig. 8B ), if shown to be constant, may separate A. galapagensis from A. nuttingi , in which the eggs are orange (cf. Fig. 8B ).

The synonymy of A. cryptodentatus with A. galapagensis , although very likely, needs confirmation by examination of the type specimens of A. cryptodentatus deposited in the collections of the Universidade Federal da Paraíba in João Pessoa, Brazil (UFPB).

GenBank number. — COI 5' EF092284 (fcn JJ-AC-28); COI 3' AF309883 (fcn 98-089) .

Figures

FIGURE 2. Alpheus galapagensis Sivertsen, 1933, color pattern, drawn from living male specimen from Playa Corona, Panama.

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.