Zuzalpheus agelas

Ríos, Rubén & Duffy, J. Emmett, 2007, A review of the sponge‑dwelling snapping shrimp from Carrie Bow Cay, Belize, with description of Zuzalpheus, new genus, and six new species (Crustacea: Decapoda: Alpheidae), Zootaxa 1602 (1), pp. 1-89 : 7-8

Zuzalpheus agelas ( Pequegnat and Heard, 1979) n. comb.

( Plate 1 )

Synalpheus agelas Pequegnat and Heard, 1979:110–116 , figs. 1–4; Dardeau 1984:12–18, Figs. 3–6 .

Material examined. ( 1) Holotype ♂ ( USNM 171424 ), CL 4.6 mm, West Flower Garden Bank, Gulf of Mexico, 25 m.

( 2) Allotype ovigerous ♀ ( USNM 171425 ), CL 4.6 mm, Florida Middle Ground, Gulf of Mexico, 30–34 m.

(3) 3 ♀ (at least one ovigerous), 3.8, 3.9, and 4.3 mm ( VIMS 93 CBC7501) , 5 ♂, 3.2 – 3.8 mm ( VIMS 93 CBC7502), Carrie Bow Cay , Belize, 5 April 1993, in demosponge Agelas clathrodes ( Schmidt 1870) , 20 m .

(4) 1 male, 4.8 mm; 1 ovigerous ♀, missing carapace, slightly larger than ♂ ( VIMS 90 CBC0101), Carrie Bow Cay , Belize, 26 April 2001, in Agelas dispar Duchassaing and Michelotti 1864 , 17 m.

(5) 1 ovigerous ♀, 4.9 mm ( VIMS 90 CBC2902), Carrie Bow Cay , Belize, 11 December 1990, in Agelas dispar , 6 m.

(6) 1 ovigerous ♀, 4.4 mm ( VIMS 93 CBC8201), 2 ♂ , 3.8 and 3.5 mm ( VIMS 93 CBC8203, 93CBC8205), spur and groove reef, Carrie Bow Cay , Belize, 6 April 1993, in Agelas dispar , 10 m.

Diagnosis. Body subcylindrical; carapace smooth, sparsely setose, with pterygostomian corner produced into bluntly acute angle, posterior margin with cardiac notch distinct. Rostrum clearly narrower than, and falling slightly short of, ocular hoods. Orbitorostral process absent. Ocular hoods dorsally convex, bluntly acute, separated from rostrum by deep adrostral sinus. Ocular process broad. Ocellary beak in lateral view broad at base, not rod-like. Stylocerite with mesial margin slightly concave and lateral margin strongly convex; tip acute, not sharp, falling distinctly short of distal margin of first segment of antennular peduncle; latter without ventromesial tooth, with 2 basal ventral processes. Basicerite with dorso-lateral corner forming right angle; longer ventrolateral spine clearly overreaching distal margin of first segment of antennular peduncle. Scaphocerite blade reduced, acute lateral spine robust, with lateral margin slightly concave, almost reaching distal margin of second segment of antennular peduncle; mesial projection at base of scaphocerite present. Third maxilliped with distal circlet of spines on distal segment and without ventrodistal spine on antepenultimate segment.

Major pereopod 1 massive, fingers shorter than half length of palm; fixed finger reduced, much shorter than dactyl; in ventral view, outer face of fixed finger without distinct lateral protuberance. Palm of chela with distal superior margin produced into prominent bluntly acute tubercle, downwardly oriented. Merus, extensor margin strongly convex, with distal flat, angular projection.

Minor pereopod 1 with palm less than 2 times longer than high; fingers shorter than palm; dactyl straight, blade-like, with short distinct subdistal teeth, perpendicular to dactyl axis; extensor margin of dactyl with conspicuous transverse dorsal setal combs; fixed finger straight, blade-like, with subdistal bump. Merus extensor margin convex, ending distally in obtuse angle.

Pereopod 2 with carpus 4-segmented, shorter than merus.

Pereopod 3 dactyl biunguiculate, with proximal tooth on flexor margin thicker than distal one; merus rather thick, usually less than 3.5 times longer than wide, without movable spines on flexor margin; coxa with mesial lamella. Pereopods 4 and 5 normal.

Pleura 1 of male with lower edge sinuous, posteroventral corner produced into thick hook; remaining pleura broadly obtuse. Pleopod 1 of male with about 3 terminal setae on endopod; pleopod 2 with marginal setae on exopod originating close to base; appendix interna on second to fifth male pleopods present. Telson posterior margin with space between spines more than one-third width of posterior margin; latter with medial convex lobe. Anal flaps, perianal setae, and postanal setal brush absent. Uropods with 1 fixed tooth, occasionally 2, on lateral margin of exopod anterior to, and distinctly removed from, slightly longer mobile spine, latter closely adjacent to internal fixed tooth.

Color ( Plate 1 ). Bright orange with distal palm and fingers of major chela brighter orange. Ovaries and eggs yellow-orange. The black stomach is prominent in freshly collected specimens.

Hosts and ecology. As indicated by its name, Zuzalpheus agelas was described from specimens living inside an orange sponge identified by Pequegnat and Heard (1979) as " Agelas dispar ". At Carrie Bow Cay, we have collected this shrimp exclusively from two species of Agelas , A. dispar , which is brown ( Zea 1987) rather than orange, and A. clathrodes , which is orange. Our collections support the suggestion in the original description that Z. agelas is a specialist associate of sponges in the genus Agelas .

Variations. In some specimens the rostrum is lanceolate rather than triangular. Sometimes the merus of the third pereopod is elongated, almost four times longer than wide. The most frequent number of lateral fixed teeth on the uropodal exopod is one, but sometimes there are two.

Distribution. Western Atlantic: Florida Keys, USA (J.E. Duffy unpublished); Bahamas ( Dardeau 1984; J.E. Duffy unpublished); Gulf of Mexico ( Pequegnat and Heard 1979; Dardeau 1984); Puerto Rico ( Dardeau 1984); Cuba (Martínez Iglesias and García Raso 1999); Belize Barrier Reef (this study); San Blas Islands, Panama (J.E. Duffy unpublished).

Remarks. This species can be diagnosed relatively easily by the combination of four carpal segments on the 2 nd pereopod, absence of a spine on dorsal margin of basicerite, and the circlet of stout spines on the third maxilliped. In life, the combination of bright orange body color with dark black stomach distinguishes Z. agelas from its congeners inhabiting Agelas spp.

Figures

PLATE 1. Zuzalpheus agelas, male. (VIMS 04CBC4301) from Agelas clathrodes, Long Reef, Belize. Zuzalpheus androsi, female (VIMS 03CBC0901) from Hyattella intestinalis, Carrie Bow Cay, Belize. Zuzalpheus bousfieldi, female (VIMS 03CBC1201) from Hyattella intestinalis, Carrie Bow Cay, Belize. Zuzalpheus bousfieldi, male (VIMS 03CBC1202) from Hyattella intestinalis, Carrie Bow Cay, Belize. Zuzalpheus brevifrons, female (VIMS 03CBC3601) from unidentified sponge, Sand Bores, Belize. Zuzalpheus brooksi, female (VIMS 05FK14) from Spheciospongia vesparium, Key Largo, Florida, USA.

FIGURE 3. Zuzalpheus dardeaui, n. sp. Paratype female 9.1 mm (USNM 1019041): a, anterior region of carapace and cephalic appendages, dorsal view; b, same, lateral view. Paratype male 7.6 mm (USNM 1019040): c, abdomen, lateral view. Paratype ovigerous female 9.2 mm (USNM 1019040): d, abdomen, lateral view. Allotype ovigerous female 9.9 mm (USNM 1019039): e, abdomen, lateral view. Paratype male 8.2 mm (VIMS 01CBC7408): f, detail of 4th–6th abdominal pleurae, lateral view. Scale bar = 1 mm for a, b; 2 mm for c, d; 2.5 mm for e; and 1.2 mm for f.

FIGURE 4. Zuzalpheus dardeaui, n. sp. Paratype male 7.6 mm (USNM 1019040): a, major first pereopod, lateral view; b, same, tip of fixed finger, ventral view; c, same, merus, lateral view; d, minor first pereopod, lateral view; e, distal portion of same, alternate lateral view. Paratype ovigerous female 9.2 mm (USNM 1019040): f, distal portion of chela of major first pereopod, lateral view. Paratype female 9.1 mm (USNM 1019041): g, distal portion of chela of major first pereopod, lateral view; h, telson and uropods, dorsal view. Scale bar = 1 mm for a, c, g; 0.66 mm for b; 0.5 mm for d, f, h; and 0.12 mm for e.

FIGURE 5. Zuzalpheus dardeaui, n. sp. Paratype male 7.6 mm (USNM 1019040): a, left third pereopod; b, same, detail of distal portion; c, left fourth pereopod; d, same, detail of distal portion; e, left fifth pereopod; f, same, detail of distal portion; g, left second pereopod; h, same, detail of distal portion. Scale bar = 1 mm for a, c, e, g; 0.25 mm for b, d, f; and 0.5 mm for h.

FIGURE 6. Zuzalpheus dardeaui, n. sp. Paratype male 7.6 mm (USNM 1019040): a, right mandible; b, right first maxilla; c, right second maxilla; d, right first maxilliped; e, right second maxilliped; f, right third maxilliped; g, same, detail of tip; h, left first pleopod; i, left second pleopod. Paratype ovigerous female 9.2 mm (USNM 1019040): j, first pleopod; k, left second pleopod with egg. Scale