Synalpheus belizensis, Anker, Arthur & Tóth, Eva, 2008

Anker, Arthur & Tóth, Eva, 2008, A preliminary revision of the Synalpheus paraneptunus Coutière, 1909 species complex (Crustacea: Decapoda: Alpheidae), Zootaxa 1915, pp. 1-28 : 19-24

Synalpheus belizensis n. sp.

( Figs. 12 , 13 , 14 I)

(?) Zuzalpheus paraneptunus (not Coutière, 1909) – Ríos and Duffy, 2007: 55, pl. 4.

Type material. Belize. Holotype, breeding female, USNM 1116695, Carrie Bow Cay, depth ~ 12 m, in cryptic sponge among rubble, coll. E. Tóth, 10 Oct 2005 [05-194, photo voucher]. Paratype: 1 male, USNM 1116696, same collection data as holotype [05-195].

Diagnosis. Rostrum not lower than orbital hoods, rather broad at base, not particularly slender, subequal to orbital teeth, with subacute tip; orbital teeth triangular, broad at base, subacute; both rostrum and orbital teeth slightly up-turned distally; notches between orbital teeth and rostrum moderately deep, between V- and U-shaped. Antennular peduncles with second segment distinctly longer than wide; stylocerite overreaching distal margin of first segment. Antenna with basicerite bearing blunt, almost non-projecting distodorsal tooth; scaphocerite without blade. Third maxilliped with crown of eight-nine spine-like setae on tip of ultimate segment. Major chela with palm about 2.5 times as long as fingers; distodorsal tooth on palm not bulging, with anteriorly directed acute point. Second pereiopod carpus with five segments, first carpal segment about four times length of second. Third pereiopod with propodus bearing nine spine-like setae (not including distal pair); dactylus stout. Uropodal exopod with two fixed teeth (including lateral tooth of diaeresis) and slender movable spine-like seta. Telson with longitudinal median depression and two pairs of moderately stout spine-like setae inserted anterior and posterior to mid-length, respectively; posterior margin broad, about half-length of anterior width, slightly rounded (see Figs. 10 , 11 ). For detailed description of general features of S. paraneptunus species complex see Dardeau (1984) and Ríos & Duffy (2007).

Etymology. The name of this new species obviously refers to the country of the type locality (Carrie Bow Cay), the Republic of Belize.

Colour pattern. Whitish semitransparent, with a few reddish chromatophores on abdomen; major chela pale beige, distal margin of palm and fingers pale orange-brown (except for pale area surrounded by darker margin on dactylus), tips amber-yellow; ovaries or fresh brood bright yellow-orange ( Fig. 14 I).

Size. Male, CL 4.3 mm; breeding female, CL 5.3 mm.

Type locality. Carrie Bow Cay, Belize.

Distribution. Presently known only from Belize.

Life history. This species probably occurs in pairs in cryptic sponges (possibly Calyx podatipa ) growing among coral rubble.

Remarks. Synalpheus belizensis n. sp. is closely related to S. bocas n. sp., differing from the latter species mainly by the presence of a more or less developed (but apparently always present) blade on the antennal scaphocerite (always absent in S. bocas n. sp.) ( Fig. 12 A), and by the less stout dorsal spine-like setae on the telson ( Fig. 12 G). In life, the two species can be separated by the colour of ovaries (or eggs / fresh embryos): bright yellow in S. belizensis n. sp., vs. green in S. bocas n. sp. ( Fig. 14 F–I). Synalpheus belizensis can be separated from S. paraneptunus , S. duffyi n. sp., S. riosi n. sp., and S. brevidactylus n. sp. by the same combination of characters as S. bocas n. sp. (see above and Table 1 ).

The male paratype of S. belizensis n. sp. ( Fig. 12 H) was collected from the same sponge as the female holotype. It has a somewhat aberrant frontal margin, and in addition, differs from the female by the somewhat longer orbital teeth; the scaphocerite with a very short blade; and the slightly more elongate second segment of the antennular peduncle. These differences are here considered to be intraspecific, however, more specimens are needed to show full range of variation in this species.

Ríos & Duffy’s (2007) record of S. paraneptunus from Carrie Bow Cays is tentatively listed under this species based on the colour photograph of a female with bright yellow embryos (see Ríos & Duffy, 2007, pl. 4).

Figures

FIGURE 10. Synalpheus bocas n. sp., paratype, male from Bocas del Toro, Panama (USNM 1116692): A, frontal region, dorsal view; B, same, lateral view; C, third maxilliped, tip of ultimate segment, lateral view; D, second pereiopod, lateral view; E, third pereiopod, lateral view; F, abdomen, lateral view; G, telson and uropods, dorsal view. Scale bar: 0.5 mm (A – E, G), 1 mm (F).

FIGURE 11. Synalpheus bocas n. sp., paratype, male from Bocas del Toro, Panama (USNM 1116692) [A – E]; paratype, male (USNM 1116690) [F]: A, major cheliped, lateral view; B, same, chela, mesial view; C, same, distal portion with opened fingers, lateral view; D, minor cheliped, lateral view; E, same, chela with opened fingers, mesial view, F, minor chela of young male with opened fingers, dorsolateral aspect. Scale bar: 0.5 mm (C – F), 1 mm (A, B).

FIGURE 12. Synalpheus belizensis n. sp., holotype, breeding female from Carrie Bow Cay, Belize (USNM 1116695) [A – G]; paratype, male (USNM 1116696) [H, I]: A, frontal region, dorsal view; B, same, lateral view; C, third maxilliped, lateral view; D, second pereiopod, lateral view; E, third pereiopod, lateral view; F, abdomen, lateral view; G, telson and uropods, dorsal view; H, aberrant frontal region, dorsal view; I, abdomen, lateral view. Scale bar: 0.5 mm (A – E, G, H), 1 mm (I), 2 mm (F).

FIGURE 13. Synalpheus belizensis n. sp., holotype, breeding female from Carrie Bow Cay, Belize (USNM 1116695): A, major cheliped, lateral view; B, same, mesial view; C, major chela, distal portion with opened fingers, lateral view; D, same, distodorsal tooth on palm, mesial view; E, minor cheliped, lateral view; F, same, carpus and chela with opened fingers, mesial view; G, same, dorsomesial aspect. Scale bar: 0.5 mm (C – G), 1 mm (A, B).

FIGURE 14. Life habitus and colour patterns. Synalpheus duffyi n. sp., Isla Grande, Panama [A, B]: A, larger queen and two smaller non-breeding colony members from the same colony, dorsal view; B, queen with embryos, lateral view. Synalpheus brevidactylus n. sp., Isla Grande, Panama [C, D]: C, breeding female and male (mated pair), dorsal view; D, breeding female, lateral view. Synalpheus bocas n. sp., Bocas del Toro, Panama [E – H]: E, male, dorsal view; F, breeding female; G, H, another breeding female, lateral and dorsal views on different backgrounds. Synalpheus belizensis n. sp., Carrie Bow Cay, Belize [I]: I, breeding female, dorsal view. Scale bars: ~ 2 mm.