Alpheus fagei Crosnier & Forest, 1965

Anker, Arthur, Hurt, Carla & Knowlton, Nancy, 2008, Revision of the Alpheus websteri Kingsley, 1880 species complex (Crustacea: Decapoda: Alpheidae), with revalidation of A. arenensis (Chace, 1937), Zootaxa 1694, pp. 51-68 : 62-65

Alpheus fagei Crosnier & Forest, 1965

Figs. 4C, 5A–C

Alpheus fagei Crosnier & Forest 1965: 603 , fig. 1; Crosnier & Forest 1966: 233, fig. 8; Wicksten 1983: 42; Kim & Abele 1988: 30.

Material examined.— São Tomé. 1 female (CL 5.0), USNM 1109195, ST 5, Lagoa Azul, shallow bay with rocky shore, from coralline algae and rocks, depth 1–3 m, coll. N. Knowlton and A. Anker, 3 Feb 2006 [fcn 06-139]; 1 male (CL 7.4), 1 ovig. female (CL 9.6), USNM 1109196, ST 10, Ilha das Cabras, off beach near light house, depth about 2 m, coarse sand and rubble, under rocks and rock crevices, coll. A. Anker, 8 Feb 2006 [fcn 06-179]; 1 ovig. female (CL 5.8), USNM 1109197, ST 5A, Lagoa Azul, shallow bay with rocky shore, from coralline algae and rocks, depth 1–3 m, coll. N. Knowlton and A. Anker, 6 Feb 2006 [fcn 06-163]; 1 male (CL 5.1) 1 ovig. female (CL 6.6), USNM 1109198, same collection data as previous specimen [fcn 06- 161, 06-162]; 1 ovig. female, CL 10.1, USNM 1109199, ST 3, 200 m west of Lagoa Azul, rocky shore with coralline algae, from holes and under rocks, intertidal, extreme low tide, coll. N. Knowlton and A. Anker, 31 Jan 2006 [fcn 06-065]; 1 male (CL 8.7), 1 ovig. female (CL 9.1) MNHN-Na 16708, ST 6A: São Tome town, near fortress, shallow bay with sand-mud and scattered rocks, under rocks, depth 0.5–1 m, coll. N. Knowlton and A. Anker, 4 Feb 2006 [fcn 06-168, 06-167]; 1 juvenile (CL not measured), USNM 1109200, ST 2, Praia Lagarto, near hospital, sand with Montastraea , zoanthids and rocks embedded in sand, intertidal (extreme low tide), coll. N. Knowlton and A. Anker, 30 Jan 2006 [fcn 06-051].

Description.—See Crosnier & Forest (1965, 1966).

FIGURE. 4. Color patterns of juveniles of Alpheus websteri Kingsley, 1880 (A); Alpheus arenensis ( Chace, 1937) (B); Alpheus fagei Crosnier and Forest, 1966 (C); A, specimen from Utila, Honduras (OUMNH 2007-20 -002); B, specimen from Las Perlas Islands, Pacific coast of Panama (USNM 1109190); C, specimen from São Tomé (USNM 1109200).

Color pattern.—Background color cream white or pale grey; carapace with two broad transverse brown bands, one band at about mid-length, somewhat extending anteriorly on mid-dorsal line (Fig. 5A, B), and one more posterior band, with concave anterior margin and more or less sinuous posterior margin (Fig. 5A, B), and extending anteriorly dorsolaterally, but not reaching first band (Fig. 5C), both bands abruptly changing direction on carapace flanks (Fig. 5C); anterolateral areas of carapace below orbital hoods dark brown (Fig. 5C); rostral area also brownish, with pale greenish-brown rostral carina; inner organs visible through carapace dorsally as large purple-brown patch; abdomen with six broad dark brown or chocolate brown transverse bands with slightly concave posterior margins, extending to ventral margin of pleurae, abruptly changing direction laterally (towards posterior) but not touching on flanks (Fig. 5C); second abdominal band bifurcating laterally, reverse V-shaped (Fig. 5C); sixth abdominal somite almost completely dark brown except for large yellow spot posteriorly (Fig. 5A, B); white bands between brown bands with intense egg-yellow bands anteriorly, fringing posterior margins of brown bands (Fig. 5A, B); tail fan mostly purple-brown, with large white areas and spots of yellow chromatophores, proximal portion of telson and uropods whitish, dorsal spines whitish; distolateral spine black; walking legs and second pereiopods pinkish semitransparent speckled with minute red chromatophores except on articulations; cheliped merus and carpus orange-brown laterally; mesial face of palm of major chela orange-brown with paler areas (Fig. 5B) and sometimes transverse white streaks (Fig. 5A); pollex darker orange-brown with whitish tip; dactylus brown-grey proximally, pink distally (Fig. 5A); palm of minor chela brown-orange, white proximally; fingers dark brown, pale grey towards tip; antennular peduncles brown distally, whitish proximally; basicerite and scaphocerite mostly whitish with occasional brown-orange spots, lateral margin and distolateral tooth of scaphocerite brown; antennular and antennal flagella pale brown; corneas grey (Fig. 5A–C); juveniles with paler bands but more contrasting pattern, especially marked white patches on major chela (Fig. 4C).

Size.—The largest examined specimen is an ovigerous female with CL 10.1 mm and TL 27.9 mm.

FIGURE. 5. Color patterns of adults of Alpheus fagei Crosnier & Forest, 1966 (A–C) and Alpheus thomasi Hendrix & Gore, 1973 (D, E); A, female from São Tomé (USNM 1109199); B, C, male from São Tomé (MNHN-Na 16708); D, male from Bocas del Toro, Caribbean coast of Panama (MNHN-Na 16707); E, ovigerous female from Bocas del Toro, Caribbean coast of Panama (USNM 1109188). Notice similarities, especially in the presence of narrow yellow bands fringing brown bands and the bifurcating band on the second abdominal somite.

Ecology.—Lower intertidal to about 35 m ( Crosnier & Forest 1966); hard bottoms, in crevices of calcareous algal crusts and overgrown rocks, also in coral rubble and under rocks on mixed sand-rock bottoms.

Type locality.— São Tomé, Gulf of Guinea.

Distribution.—Eastern Atlantic: Ivory Coast; Gulf of Guinea: São Tomé and Principe ( Crosnier & Forest 1966).

Remarks.— Alpheus fagei differs from A. websteri and A. arenensis mainly by the shorter basicerite, not reaching level of stylocerite (vs. reaching to or slightly beyond stylocerite in A. websteri and A. arenensis ); the third pereiopod bearing a simple dactylus (vs. biunguiculate in A. websteri and A. arenensis ); and in life, by the palm of the major chela lacking dark spots (vs. with spots in A. websteri and A. arenensis ) (see also Table 1 ). The color pattern of A. fagei is remarkably similar to that of the western Atlantic A. thomasi (Fig. 5). The main color differences between the two species are the relatively broader bands on the carapace in A. fagei , and a brighter, more contrasting pattern on the major claw in A. thomasi . In addition to these, A. fagei may be easily separated from A. thomasi by the same morphological criteria as A. websteri (see above).

GenBank number.— EU339464 [06-086, not deposited, São Tomé], EU339465 [06-119, not deposited, São Tomé].