Alpheus vanderbilti Boone, 1930

Anker, Arthur, Hurt, Carla, Jara, Javier A. & Knowlton, Nancy, 2008, Revision of the Alpheus cylindricus Kingsley, 1878 species complex (Crustacea: Decapoda: Alpheidae), with revalidation of A. vanderbilti Boone, 1930, Zootaxa 1943, pp. 53-68 : 60-64

Alpheus vanderbilti Boone, 1930

( Figs. 2; 3B, C; 4E–H, J, K)

Alpheus vanderbilti Boone 1930: 163 , fig. 5, pl. 58.

Alpheus cylindricus (not sensu Kingsley 1878) – Zimmer 1913: 394; Crosnier & Forest 1965: 606; Crosnier & Forest 1966: 257, fig. 16; Hendrix 1971: 71; Coelho & Ramos 1972: 149; Chace 1972: 65; Pequegnat & Ray 1974: 246, fig. 49d; Ray 1974: 92, figs. 72–78; Christoffersen 1979: 310; Christoffersen 1980: 50; Coelho & Ramos-Porto 1980: 135; Coelho et al. 1980: 48; Abele & Kim 1986: 196, 206-207, fig. a–c; Sterrer 1986: 326, text. pl. 105, pl. 9, fig. 7; Rodríguez 1986: 138, fig. 33; Martínez-Iglesias et al. 1993: 11; Knowlton et al. 1993: 1630 (part.); Martínez- Iglesias et al. 1996: 33; Martínez-Iglesias et al. 1997: 404, fig. 9; Williams et al. 2001: 377 (part.); McClure 2005: 136, not fig. 11; Coelho et al. 2006: 51.

Crangon cylindricus (not sensu Kingsley 1878) – Schmitt 1924: 74; Pearse 1950: 150.

Material examined. Panama ( Caribbean coast). 1 male (CL 5.9), USNM 1109165 , San Blas Islands, Tiantupo, in loggerhead sponge, Spheciospongia vesparia , coll. N. Knowlton et al., 22 Feb 1993 [fcn C-761] ; 1 male (CL 4.3), USNM 1109166 , San Blas Islands , Tiantupo, in loggerhead sponge, Spheciospongia vesparia , coll. N, Knowlton et al., 22 Feb 1994 [fcn C-763] ; 1 male (CL 6.7), USNM 1109167 , San Blas Islands , coll. N, Knowlton et al., 4 Apr 1992 [fcn C-435] ; 1 male (CL 5.3), USNM 1109168 , San Blas Islands , in sponge, coll. N, Knowlton et al., 3 Apr 1992 [fcn C-415] ; 1 female (CL 5.3), USNM 1109169 , San Blas Islands , Tiantupo, in loggerhead sponge, coll. N, Knowlton et al., 23 Feb 1994 [fcn C-764] ; 1 male (CL 6.5), USNM 1109170 , same collection data as previous specimen [fcn C-762] ; 1 male (CL 5.4), USNM 1109171 , San Blas Islands , in green sponge, coll. N, Knowlton et al., 4 Apr 1992 [fcn C-416] ; 1 male (CL 5.2), 1 ovig. female (CL 4.4), USNM 1109172 , San Blas Islands , “old yellow” (in yellow sponge?), coll. N, Knowlton et al., 4 Apr 1992 [fcn C-417, C-418] ; 1 female (CL 5.1), USNM 1109173 , San Blas Islands , Tiantupo, in loggerhead sponge, Spheciospongia vesparia , coll. N, Knowlton et al., 23 Feb 1994 [fcn C-765] . São Tomé. 1 male (CL 9.7), USNM 1109174 , ST 12: Ilha Santana , from crevices of rocks, depth 15–20 m, coll. N. Knowlton and F. Nunes 9 Feb 2006 [fcn 06-202] ; 1 female (CL 10.0), OUMNH-ZC 2007-13 - 035 , same collection data as for previous specimen [fcn 06-201] ; 1 male (CL 7.5), USNM 1109175 , same collection data as for previous specimen [fcn 06-200, cephalothorax and tail fan only] ; 1 male (CL 7.8), USNM 1109176 , ST 4: 2 km west of Lagoa Azul , near ship wreck, off rocky shore with crusts of coralline algae, from crevices of massive rock, depth at low tide about 4 m, coll. A. Anker and N. Knowlton, 1 Feb 2006 [fcn 06-104]; 1 ovig. female (CL 7.5), USNM 1109177 , same collection data as for previous specimen [fcn 06-101]; 1 ovig. female (CL 7.9), USNM 1109178 , same collection data as for previous specimen [fcn 06-102] ; 1 male (CL 7.1), USNM 1109179 , same collection data as for previous specimen [fcn 06-105] ; 1 male (CL 8.5), USNM 1109180 , same collection data as for previous specimen [fcn 06-106] .

Diagnosis. See under A. cylindricus , from which A. vanderbilti is morphologically virtually undistinguishable, whilst differing in color and DNA sequences (see below).

Description. For detailed description and some figures see Boone (1930); for additional illustrations see Zimmer (1913), Crosnier & Forest (1966), Pequegnat & Ray (1974), Rodríguez (1986) and Martínez-Iglesias et al. (1997).

Color pattern. Western Atlantic specimens: background color pale grey, semitransparent; carapace with large complexly shaped patch of red chromatophores on gastric region, central area of this patch colorless, patches of red chromatophores also on rostral and post-rostral region; deep red transverse band also present along posterior margin of carapace and articulation between carapace and abdomen; abdomen with broad longitudinal band of red chromatophores running along lateral surface of pleurae; mediodorsal area of first to fourth somites colorless, that of fifth and sixth somites with red chromatophores; walking legs colorless; second pereiopod mostly colorless with some reddish chromatophores; antennular peduncles bright red; antennal peduncles including scaphocerite mostly transparent, margins of scaphocerite and basicerite orange-red, carpocerite distally reddish; antennular and antennal flagella pale yellow; cheliped meri and carpi mostly colorless mesially, reddish laterally; palm of major chela red-orange, darker distally; linea impressa delimiting paler, grey-pink oval proximolaterally; dactylus purple-red with whitish tip; minor chela pale red-orange, purple-red distally and on fingers ( Fig. 2, 3B). Eastern Atlantic specimens: very similar to western Atlantic specimens; gastric region of carapace with more regular and less contrasting oval patch, with slightly larger colorless central area ( Fig. 3C); developing embryos (“eggs”) in females bright yellow-orange.

Size. The CL and TL of the San Blas specimens ranged from 4.4 to 6.7 mm, and 10.8 mm to 17.0 mm, respectively. The largest specimen from São Tomé is a female with CL 10.0 mm and TL 28.7 mm.

Ecology. Western Atlantic: lower intertidal (rare) and subtidal to about 36–45 m ( Boone 1930; Christoffersen 1979); more common in shallow subtidal (3–10 m); lives in male-female pairs in loggerhead sponges, Spheciospongia vesparia (Lamarck, 1816) ( Pearse 1950; Chace 1972); also in algal crusts and crevices of dead corals ( Christoffersen 1979; Rodríguez 1986). Eastern Atlantic: lower intertidal (rare) and shallow subtidal to about 73 m; in crevices of coral rocks and crusts of red algae on basaltic rocks ( Crosnier & Forest 1966); all our specimens were extracted from crevices and tunnels thinly lined with purple or yellow sponges in coral rocks ( Fig. 3E).

Type locality. Sand Key, Key West , Florida .

Distribution. Western Atlantic: from Florida and Bermuda to Caribbean, Gulf of Mexico and northwestern Brazil ( Chace 1972; Sterrer 1986; Christoffersen 1998). Specific localities include: Bermuda ( Sterrer 1986); Florida: southern Florida and Florida Keys ( Boone 1930; Hendrix 1971); Texas: West Flower Garden Bank ( Pequegnat & Ray 1974); Bahamas: Bimini ( Pearse 1950); Grenadines ( Chace 1972); Barbados ( Zimmer 1913; Schmitt 1924); Cuba: Gulf of Batabano ( Martínez-Iglesias et al. 1997); Panama: San Blas Islands (present study); Venezuela: Los Roques ( Rodríguez 1986); Brazil: Maranhao, Paraiba and Bahia ( Coelho & Ramos 1972; Christoffersen 1979, 1998). Eastern Atlantic: São Tomé, Principe and Annobon in the Gulf of Guinea ( Crosnier & Forest 1966; present study).

Variation. Like the previous species, A. vanderbilti is variable in the configuration of the orbital teeth and rostrum ( Christoffersen 1979; see also Fig. 4E–H) and in the shape of the antennal scaphocerite ( Fig. 4J, K, compare with Fig. 4I).

Remarks. Alpheus vanderbilti may be separated from A. cylindricus by the presence of a patch of red chromatophores on the posterior dorsal half of the carapace and the colorless mediodorsal band laterally without distinct triangles (not “spruce-shaped”) and being interrupted on the fifth segment by a transverse red band, while the sixth somite is almost entirely red (compare Figs. 2, 3B, C and Figs. 1, 3A).

The eastern Atlantic specimens of A. vanderbilti differ from the western Atlantic specimens and from A. cylindricus only by some minor details in the color pattern, e.g., by the less contrasting red patch on the gastric region of the carapace, with a larger colorless central area (cf. Fig. 3C). These differences are too subtle and probably inconsistent (red chromatophores may fade away completely or become more intense in stressed specimens) to be considered as taxonomically important.

In all examined specimens from São Tomé, the uropodal endopod is furnished with a row of strong spines (usually 9–11) on the distolateral margin ( Fig. 5A); these spines are also present in the western Atlantic specimens ( Ray 1974: fig. 74; Christoffersen 1979) and in A. cylindricus ( Kim & Abele 1988: fig. 19l). They were apparently overlooked by Crosnier & Forest (1966) and not illustrated on the figure of the tail fan (fig. 16h). Furthermore, this figure does not show a deep mediodorsal groove on the telson, which is conspicuous in all of our specimens ( Fig. 5B), and which is also present in A. cylindricus (cf. Kim & Abele 1988: fig. 19l).

Other subtle but diagnostic features of both A. vanderbilti and A. cylindricus are the presence of a small acute tooth on the distomesial margin of the antennal carpocerite ( Fig. 5C); the presence of an acute tooth on both the dactylus and pollex of the major chela ( Fig. 5D); and especially the setation pattern on the chela of the second pereiopod (P2, Fig. 5E), consisting of particularly dense rows of setae ( Fig. 5F). This setation pattern is unusual and perhaps unique among Alpheus species (A. Anker, pers. obs.). Dense setal brushes are also present on the P2 of most Synalpheus species , but these patterns are different from those of A. cylindricus and A. vanderbilti (A. Anker, pers. obs.).

GenBank accession number. EU652329 , EU652330 ( A. vanderbilti WA ) ; EU652327 , EU652328 ( A. vanderbilti EA ) (specimens will be deposited in USNM) .