Zuzalpheus

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 : 63-68

Zuzalpheus ul, n. sp.

( Figs. 27–30 , Plate 5 )

Synalpheus sp. 5 , new species Ríos 2003:140, figures 2–26 through 2–29, plate I.

Material examined. ( 1) Holotype ♂, 3.5 mm ( USNM 1019053 , VIMS 01CBC4605), allotype ovigerous ♀, 3.9 mm ( USNM 1019054 , VIMS 01CBC4604), Sand Bores , Belize, 30 April 2001, in Hymeniacidon caerulea , 2 m.

(2) Ovigerous ♀, 4.0 mm, 2 ♂, 3.0, 3.8 mm ( VIMS 90 SB1008), San Blas Islands , Panama, 13 April 1990, no host recorded, 1 m ; ♂, 5.1 mm, ovigerous ♀, 3.4 mm ( VIMS 90 SB0702), Porvenir and Aguadargana Islands, Panama, 12 April 1990, no host recorded .

Description of holotype. Body subcylindrical; carapace smooth, sparsely setose, with pterygostomian corner produced into bluntly acute angle, and posterior margin with cardiac notch distinct. Rostrum clearly narrower than ocular hoods, slightly longer than ocular hoods, and distally upturned; margins in dorsal view, straight. Orbitorostral process absent. Ocular hoods dorsally convex; in dorsal view, squared off and blunt anteriorly, margins convex, separated from rostrum by deep adrostral sinus. Ocular processes present, but not elongated. Ocellary beak in lateral view not rod-like. Stylocerite slender; mesial margin slightly concave; tip acute; distinctly shorter than distal margin of first segment of antennular peduncle; latter without ventromesial tooth, and with 2 basal ventral processes. Basicerite without spine on dorsolateral corner, and with longer ventrolateral spine clearly overreaching tip of stylocerite. Scaphocerite blade reduced, acute lateral spine robust, with lateral margin slightly concave, not overreaching antennular peduncle, slightly shorter than basicerite lateral spine; mesial projection at base of scaphocerite present. Maxilliped 3 with distal circlet of spines on distal segment and without ventrodistal spine on antepenultimate segment; other mouthparts as figured.

Major pereopod 1 massive, fingers shorter than half length of palm; fixed finger reduced, noticeably shorter than dactyl; in ventral view, outer face of fixed finger without pronounced protuberance. Palm of chela with distal superior margin produced into prominent tubercle with acute downwardly directed spine on its ventral face. Merus, extensor margin convex, with distal angular projection.

Minor pereopod 1 with palm about 2 times longer than high; fingers shorter than palm; dactyl with flexor margin straight, blade-like, with subdistal accessory protuberance parallel to dactyl axis; transverse dorsal setal combs on extensor surface of dactyl very conspicuous; fixed finger with flexor margin straight, bladelike, and subdistal accessory bump. Extensor margin of merus convex, ending in obtuse angle.

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

Pereopod 3 stout; dactyl biunguiculate, with clearly unequal teeth; and flexor tooth wider at base than extensor tooth; propodus with nine mobile spines on flexor margin and one pair on distal end; carpus with 1 mobile distal spine; merus without any spine on flexor margin; mesial lamella on coxa present. Pereopod 4 similar to third, but weaker. Pereopod 5 similar to fourth, but slender, without distal spine on carpus, and with 7 rows of setal combs on ventral face of propodus.

Pleura 1 of male with posterior corner distinctly produced ventrally and anteriorly, hook-like; second pleura of male with lower margin slightly concave, posterior corner broadly rounded; third to fifth pleura with posterior margin forming acute angle, not sharp. Pleopod 1 of male with seven 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 about one-third of distal margin; marginal convex lobe present; posterior corners adjacent to spines obtuse. Anal flaps, perianal setae, and postanal setal brush absent. Uropods with 5 fixed teeth on outer margin of exopod.

Color ( Plate 5 ). Live specimens are translucent with scattered reddish chromatophores regularly distributed. The distal edges of the major chela have a dull to bright orange tone. The digestive gland is maroongreen and the eyes are white. An ovigerous female had a faint hue of white along the lateral margins of the body and bright orange ovaries.

Etymology. The specific name is a Mayan word that describes a location in a space; it could be translated as “inside” or “within, with a sense of under”. It alludes to the sponge-dwelling habits of this and many other species of Zuzalpheus .

Variations. Several of the specimens have an abnormally reduced rostrum not reaching beyond half the length of the ocular hoods; one ovigerous female is lacking the rostrum altogether. The blade on the scaphocerite is conspicuously reduced, but always present, at least on one side, and it normally has short marginal setae throughout. In one female paratype, the spine overhanging the base of the dactyl on the major chela is slightly twisted inward. The number of fixed teeth on the outer margin of the uropodal exopod varies from 4 to 6, rarely 7, with 5 teeth most frequent.

Ecology. Zuzalpheus ul, n. sp., is one of several species found in canals of the midnight blue sponge Hymeniacidon caerulea . It has also been found inside a white unidentified soft sponge.

Distribution. San Blas Islands, Panama; Belize Barrier Reef (this study).

Remarks. This species is closely related to Zuzalpheus pandionis , Z. dardeaui , n. sp., and Z. yano , n. sp., but can be distinguished from them by the presence of a minute blade on the scaphocerite, a rounded posterior corner on the second male pleura, and clearly unequal spines on the posterior margin of the telson ( Table 1). Also, full grown individuals of Z. ul, n. sp., are never as large as those of the other species. Some of the specimens identified as Synalpheus grampusi by Coutière (1909) resemble Z. ul, n. sp., but the predicament of trying to retain that old name would prompt more instability in the taxonomy of the genus. See additional remarks under both Z. pandionis and Z. yano , n. sp.

Figures

PLATE 5. Zuzalpheus sanctithomae, female (VIMS 01CBC6001) from Hymeniacidon caerulea, Sand Bores, Belize. Zuzalpheus williamsi, female from Hymeniacidon caereulea. Zuzalpheus ul, female (VIMS 01CBC4002) from Hymeniacidon caereulea, Sand Bores, Belize. Zuzalpheus ul, male (VIMS 01CBC4001) from Hymeniacidon caerulea, Sand Bores, Belize. Zuzalpheus yano, female (VIMS 03P2401) from Lissodendoryx colombiensis, Isla Pastores, Bocas del Toro region, Panama. Zuzalpheus yano, female (VIMS 03P2401) from Lissodendoryx colombiensis, Isla Pastores, Bocas del Toro region, Panama. Zuzalpheus yano, male (VIMS 03P2403) from Lissodendoryx colombiensis, Isla Pastores, Bocas del Toro region, Panama.

FIGURE 27. Zuzalpheus ul, n. sp. Holotype male 3.5 mm (USNM 1019053): a, anterior region of carapace and cephalic appendages, dorsal view; b, same, lateral view; c, abdomen, lateral view; d, telson and uropods, dorsal view; e, left second pereopod. Scale bar = 1.0 mm for a, b, d, 1.5 for c, and 0.9 mm for e.

FIGURE 28. Zuzalpheus ul, n. sp. Allotype female 3.9 mm (USNM 1019054): a, abdomen, lateral view; b, minor first pereopod, lateral view; c, same, detail of distal portion (setal combs omitted), alternate lateral view; d, outer margin of exopod of right uropod; e, right corner of telson, lateral view; f, left first pleopod; g, left second pleopod. Holotype male 3.5 mm (USNM 1019053): h, chela of major first pereopod, lateral view; i, same, detail of distal portion, alternate lateral view; j, same, tip of fixed finger, ventral view. Scale bar = 1 mm for a, b, 0.6 mm for c, f, g, 0.5 for d, e, and 0.9 for h, i, j.

FIGURE 29. Zuzalpheus ul, n. sp. Holotype male 3.5 mm (USNM 1019053): 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 first pleopod; h, left second pleopod. Scale bar = 1 mm for a, c, e, g, h, and 0.28 mm for b, d, f.

FIGURE 30. Zuzalpheus ul, n. sp. Mouthparts. Holotype male 3.5 mm (USNM 1019053): a, left mandible; b, left first maxilla; c, left second maxilla; d, left first maxilliped; e, left second maxilliped; f, left third maxilliped. Scale bar = 1 mm for a, b, and 1.8 mm for c, d, e, f.