Zuzalpheus williamsi ( Ríos and Duffy, 1999 ) Ríos, Rubén & Duffy, J. Emmett, 2007

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 : 68-69

publication ID	https://doi.org/ 10.11646/zootaxa.1602.1.1
publication LSID	lsid:zoobank.org:pub:24A69D4F-F24D-4042-9149-3548430509F3
persistent identifier	https://treatment.plazi.org/id/03CB7D6B-5721-FFF4-1DBB-FBB5FE486854
treatment provided by	Felipe
scientific name	Zuzalpheus williamsi ( Ríos and Duffy, 1999 )
status	comb. nov.

Treatment

Zuzalpheus williamsi ( Ríos and Duffy, 1999) n. comb.

( Plate 5 View PLATE 5 )

Synalpheus williamsi Ríos and Duffy 1999: 541 View in CoL , fig. 1–6; Ríos 2003:152, figures.

Material examined. ( 1) Holotype ♂ ( USNM 276158 View Materials ), 3.6 mm, allotype ovigerous ♀, 4.5 mm ( USNM- 276159 ), Carrie Bow Cay , Belize, 13 June 1996, in Hymeniacidon caerulea , 18 m.

(2) Paratypes: ♂, 4.4 mm, 2 ovigerous ♀, 4.3, 4.8 mm ( USNM 276160 View Materials ), Carrie Bow Cay , Belize, 4 April 1993, in H. caerulea , 13 m ;

(3) Paratype ♂, 2.3 mm ( CNCR 17987 ) Carrie Bow Cay , Belize, 12 June 1996, in H. caerulea , 18 m .

(4) Paratype ♂, 3.7 mm ( MNHN Na 13561) Ulagsukun Reef , Panamá, 17 January 1991, in H. caerulea , 1– 2 m .

(5) 1 ♂ ( VIMS 91 P6301), 4.1 mm, Mamitupo Reef , San Blas Islands, Panama, 19 Jan 1991, in orange tubular sponge, 1– 2 m .

Diagnosis. Body subcylindrical; carapace smooth, sparsely setose, with pterygostomian corner produced into bluntly acute angle, and posterior margin with cardiac notch distinct. Rostrum about as long as, but clearly narrower than, ocular hoods, and distally upturned; margins in dorsal view, straight; ventral margin convex. Orbitorostral process absent. Ocular hoods dorsally convex; in dorsal view, acute, separated from rostrum by deep adrostral sinus. Ocular processes broad. Ocellary beak in lateral view, with inner margin concave and exterior convex. Stylocerite slender; mesial margin slightly concave; tip acute; reaching about as far as distal margin of first antennular peduncle; this latter segment without ventromesial tooth, and with 2 basal ventral processes. Basicerite with broad spine on dorsal margin, and with longer ventrolateral spine reaching distal half of second segment of antennular peduncle. Scaphocerite blade broad, slightly reduced, acute lateral spine robust, with lateral margin slightly concave, clearly overreaching antennular peduncle; mesial projection at base of scaphocerite present. Maxilliped 3 with distal circlet of spines on distal segment and without ventrodistal spine on antepenultimate segment

Major pereopod 1 massive, fingers clearly not longer than half length of palm; fixed finger reduced, much shorter than dactyl; in ventral view, outer face of fixed finger with a strong obtuse basal protuberance. Palm of chela with distal superior margin produced into prominent tubercle with seconadry acute spine on ventral surface. Merus, extensor margin strongly convex, with distal flat angular projection.

Minor pereopod 1 with palm clearly less than 2 times longer than high; fingers clearly shorter than palm; dactyl with flexor surface excavate, with subdistal accessory bump oriented perpendicular to dactyl axis; transverse dorsal setal combs on extensor surface of dactyl very conspicuous; fixed finger with flexor surface obliquely concave, and subdistal accessory bump. Extensor margin of merus convex, with flat distal angular projection.

Pereopod 2 with carpus 5-segmented, slightly longer than merus.

Pereopod 3 slender; dactyl biunguiculate, with flexor tooth slightly thicker than extensor tooth; merus without movable spines on flexor margin; mesial lamella on coxa present. Pereopods 4 and 5 normal.

Pleura 1 of male with posterior corner distinctly produced ventrally into anteriorly directed hook; second pleura of male broadly rounded. Pleopod 1 of male, with 4 or 5 terminal setae on endopod; second pleopod of male with marginal setae on exopod originating close to base; appendix interna on second to fifth male pleopods, present. Telson, space between distal spines greater than one-third of distal margin; marginal convex lobe present; posterior corners adjacent to spines rectangular. Anal flaps, perianal setae, and postanal setal brush absent. Uropods with 3 to 6 fixed teeth on outer margin of exopod.

Color ( Plate 5 View PLATE 5 ). Translucent faint gold to golden brown, with tips of chelae (fingers and distal part of palm included) of first pereopods bright orange to red; second legs golden; third to fifth, transparent; and traces of blue in the gut and in the branchiae. These traces were the same dark blue as the host sponge, Hymeniacidon caerulea , and they still can be seen in some of the preserved specimens ( Ríos and Duffy 1999).

Variations. The number of immovable teeth on the lateral margin of the uropodal exopod varies from three to six, with a mode of four; this variation may relate to size and perhaps sex, considering that the smaller specimens have fewer teeth, and that the only 2 specimens with 6 teeth were males ( Ríos and Duffy 1999).

Hosts and ecology. Zuzalpheus williamsi is most often found within the midnight-blue sponge Hymeniacidon caerulea . We have recorded occasional specimens in an unidentified orange tubular sponge growing among coral rubble ( Ríos and Duffy 1999), and in another unidentified yellow sponge.

Distribution. Western Atlantic: San Blas islands, Panama; Belize Barrier Reef (this study).

Remarks. Z. williamsi can be unequivocally distinguished from the morphologically similar Z. goodei by several features of the latter, which include lack of ventrolateral protuberance on the fixed finger of the major chela; a wider submesial fixed tooth, a shorter mobile spine, and more fixed teeth on the outer margin on the uropodal exopod; the presence of a tuft of setae behind the anal opening; and the absence of marginal setae around the anal opening.