Zuzalpheus elizabethae, 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 : 23-29

Zuzalpheus elizabethae , n. sp.

( Figs. 7–10 , Plate 2 )

Synalpheus “ rathbunae A”: Duffy 1996c; Morrison et al. 2004; Macdonald et al. 2006.

Synalpheus sp. 2 , new species Ríos 2003: 67, figures 2–6 through 2–9, plate III.

Material examined. ( 1) Holotype ♂, 3.0 mm ( USNM 1019042 , VIMS 01CBC6602), allotype ovigerous ♀, 3.6 mm ( USNM 1019043 , VIMS 01CBC6601), The Pinnacles (Sand Bores), SW of Carrie Bow Cay, Belize,

2 May 2001 in demosponge Hymeniacidon caerulea , 2 m. Paratypes: 1 ♂, 2.7 mm ( USNM 1019044 , VIMS 01CBC6602), 1 ♂, 2.9 mm ( USNM 1019045 , VIMS 01CBC6602), from same sponge specimen as holotype .

(2) 1 ♂, 3.1 mm ( USNM 1019046 , VIMS 99CBC2803), outer ridge (16°48'N, 88°05'W) Carrie Bow Cay , Belize, 6 Dec 1999, in Lissodendoryx sp. , 18 m .

(3) 1 ovigerous ♀ ( VIMS 99 CBC5101), 4.0 mm, 5 ♂ ( VIMS 99 CBC5105–99CBC5109), 3.0– 3.3 mm, from colony of 101 individuals, outer ridge at Carrie Bow Cay , Belize, 9 December 1999, in Lissodendoryx sp. , ~ 15 m.

(4) 1 ovigerous ♀ ( VIMS 04 CBC1702), 3.4 mm, 26 ♂ ( VIMS 04 CBC1701), 2.5–3.0 mm, from a colony of 30 individuals, The Pinnacles (Sand Bores), SW of Carrie Bow Cay, Belize, 13 March 2004, in Hymeniacidon caerulea , 2 m.

(5) 1 ovigerous ♀ ( VIMS 99 CBC2901), 3.9 mm, 14 ♂ ( VIMS 99 CBC2903–99CBC2916), 2.9–3.5 mm, from a colony of 122 individuals, outer ridge at Carrie Bow Cay , Belize, 6 December 1999, in Lissodendoryx sp. , ~ 15 m.

Description of holotype. Body subcylindrical; carapace smooth, sparsely setose, with pterygostomian corner produced into broad acute angle, posterior margin with cardiac notch distinct. Rostrum lanceolate, about as long as, but clearly narrower than, ocular hoods, distally upturned. Ventral surface of carapace behind rostrum flat. Ocular hoods dorsally convex; in dorsal view, broad, bluntly triangular, margins slightly convex, separated from rostrum by deep adrostral sinus. Ocular process like a swollen thick surface. Ocellary beak in lateral view rod-like. Stylocerite thick; mesial margin slightly concave; tip acute; distinctly shorter than 1 st segment of antennular peduncle; latter segment without ventromesial tooth, and with 2 basal ventral processes. Basicerite with strong sharp spine on dorsal margin, reaching about as far as tip of stylocerite, and with longer lateral spine almost reaching distal margin of 2 nd segment of antennular peduncule. Scaphocerite blade absent, lateral spine robust, with lateral margin straight, clearly overreaching antennular peduncle, but not reaching as far as distal margin of carpocerite; mesial corner at base of scaphocerite obtuse. Maxilliped 3 with distal circlet of spines on distal segment and without ventrodistal spine on antepenultimate segment.

Major pereopod 1 massive, somewhat inflated proximally, fingers clearly not longer than half length of palm; fixed finger reduced, clearly shorter than dactyl; in ventral view, outer face of fixed finger with an obtuse basal protuberance. Palm of chela with distal superior margin produced into prominent tubercle with acute ventrally directed spine. Merus with extensor margin strongly convex, with distal angular projection.

Minor pereopod 1 with palm less than 2 times longer than high; fingers clearly shorter than palm; dactyl with flexor surface obliquely concave, with no hint of subdistal tooth; transverse dorsal setal combs on extensor surface of dactyl very conspicuous, arranged in two distinct sets, the mesial one shorter; fixed finger with flexor surface obliquely concave, and no hint of second (subdistal) tooth. Extensor margin of merus convex, ending in obtuse angle.

Pereopod 2 with carpus 4-segmented, about as long as merus.

Pereopod 3 slender; dactyl biunguiculate, with proximal tooth clearly thicker than distal one; propodus with a row of 5 mobile spines on the flexor margin, and two paired subdistal spines; carpus about half as long as propodus, with a delicate mobile spine on distal flexor corner; merus longer than propodus, slightly more than 3 times as long as wide, without movable spines on flexor margin; ischium subtrapezoidal, about as long as carpus, devoid of spines; basis shorter than ischium, lower margin strongly convex; coxa with mesial lamella present. Pereopods 4 and 5 similar to 3 rd, but 5 th with 4 transverse rows of setae on flexor margin of propodus, and carpus without distal spine.

Pleura 1 of male with posteroventral corner strongly produced into tooth, with posterior margin convex, anterior corner slightly produced into acute angle; pleura 2–5 of male produced into acute angle ventroposteriorly. Pleopod 1 of male with 3 or 4 terminal setae on endopod; pleopod 2 of male with marginal setae on exopod originating near midpoint; appendix interna on male pleopods 2–5 present. Telson with space between posterior marginal spines equal to one-third width of posterior margin, and without convex lobe; posterior cor- ners adjacent to spines obtuse. Anal flaps, perianal setae, and postanal setal brush all absent. Uropods with 2 fixed teeth on outer margin of right exopod and one on left anterior to, and distinctly removed inwards from, movable spine, mesial fixed tooth slightly superimposed over mobile spine on left side; both of these abnormally duplicated on right exopod.

Color ( Plate 2 ). Translucent gold-orange with sparse chromatophores; the fingers and distal margin of palm of major chela are more intense orange. Digestive gland is olive-green to brown. Ovaries and eggs bright yellow-orange to red-orange.

First larva. Eight newly hatched larvae were obtained in the laboratory from a wild-caught ovigerous female (VIMS 93P3705). These first larvae are crawling megalopae similar to those described from Z. brooksi ( Dobkin 1965) . They have the front of the carapace trispinose, covering the eyes; both pairs of chelae are functional and not dimorphic; the carpus of the second pair has 3 segments; the pleopods and the uropods are both biramous. The first larva of Z. elizabethae , n. sp., differs from that of Z. brooksi in the following details: the fingers of the first pair of chelae are simple, not bifid; the telson has only one pair of spines on the distal margin; the scaphocerite is more slender, without any suggestion of a blade.

Etymology. We name this species after Dr. Elizabeth Canuel, Virginia Institute of Marine Science, in appreciation of her assistance with our early field research on Zuzalpheus and continuous support while studying these shrimps.

Variations. The number of fixed teeth on the exterior margin of the uropodal exopod is most frequently 2, occasionally 1 or 3, with rare records of 4 and 5 only in one of the uropods. In a few specimens one or both of the second to fourth pleura have 2 points instead of the normal 1, in almost every one of these instances, again it only happens on just one of the two sides of the abdominal segment. The holotype has a supernumerary pleopodal ramus emerging anteriorly to the first right pleopod, a peculiar abnormality that has not been recorded previously.

Hosts and ecology. In Belize, we have collected Zuzalpheus elizabethae , n. sp. most frequently from species of Lissodendoryx , including L. cf. strongylata and L. sp. on the outer reef ridge, and from L. colombiensis in shallow water, as well as from Hymeniacidon caerulea . There are also occasional records from other sponges. This species lives in eusocial colonies, consisting of tens to hundreds of individuals with only one or two breeding females. Whereas all other eusocial Zuzalpheus species in our area are reliably found in all or most specimens of at least one host species ( Duffy et al. 2000, Macdonald et al. 2006), Z. elizabethae exhibits a more “fugitive” distribution, being found in only occasional specimens of the several hosts from which it has been recorded.

Distribution. Florida Keys, USA (J.E. Duffy unpublished); Lee Stocking Island, Bahamas (K.S. Macdonald, pers. comm.); San Blas Islands, Panama (as S. “ rathbunae A”, Duffy 1996c); Belize Barrier Reef (this study).

Remarks. Z. elizabethae n. sp. is one of a complex of morphologically similar species related to Z. rathbunae . Aside from the genetic differences already documented ( Duffy 1996c), the following morphological characters appear consistent in separating them ( Table 2). The anterior corner of the first pleura in males of both Z. elizabethae , n. sp., and Z. regalis is clearly produced into an acute angle, whereas it is broadly rounded in Z. rathbunae . Also, the tubercle dorsally overhanging the base of the dactyl on the major first chela lacks the accessory spinule and is distinctly acute and upwardly oriented in Z. rathbunae , but it is blunter and has a small spine in the two other species. Additionally, Z. regalis differs from Z. elizabethae , n. sp., by having the abdominal pleura less pointed, a conspicuous fringe of long setae on the lower margin of the first abdominal pleura, and more slender fingers on the second chelae. Samples of Z. elizabethae , n. sp., collected from Lissodendoryx colombiensis in Panama have a remarkably high incidence of an abdominal parasitic isopod; every specimen appeared to be a partially feminized male, with the abdominal pleura broadly rounded, and an occasional hint of the anterior angle on the first one. The major chela in the Panamian specimens is indistinguishable from that of Z. elizabethae , n. sp., but the final identity of these samples remains to be established.

Z. elizabethae Z. filidigitus Z. rathbunae Z. regalis

Major Pereopod 1 chela, anterodorsal palmar margin inflated + spine inflated + spine flared, no spine inflated + spine

Minor Pereopod 1 chela, dactyl simple accessory spine simple simple

Male 1 st pleura, posterior corner long, hooked short, hooked long, acute long, hooked

Male 2nd pleura acute point widely obtuse acute point thick point

Figures

PLATE 2. Zuzalpheus carpenteri, female (VIMS 04CBC4202) from Agelas clathrodes, Long Reef, Belize. Zuzalpheus carpenteri, male (VIMS 04CBC4201) from Agelas clathrodes, Long Reef, Belize. Zuzalpheus chacei, female (VIMS 01CBC1101) from Lissodendoryx cf. strongylata, Curlew Reef, Belize. Zuzalpheus dardeaui, female (VIMS 01CBC7407) from Lissodendoryx colombiensis, Twin Cays, Belize. Zuzalpheus dardeaui, male (VIMS 01CBC706) from Lissodendoryx colombiensis, Twin Cays, Belize. Zuzalpheus elizabethae, female (VIMS 03CBC0801) from Lissodendoryx sp., Carrie Bow Cay, Belize.

FIGURE 7. Zuzalpheus elizabethae, n. sp. Holotype male 3.0 mm (USNM 1019042): a, anterior region of carapace and cephalic appendages, lateral view; b, same, dorsal view; c, abdomen, lateral view. Paratype male 2.9 mm (USNM 1019045): d, telson and uropods, dorsal view. Paratype male 2.7 mm (USNM 1019044): e, first pleopod; f, second pleopod. Allotype ovigerous female 3.6 mm (USNM 1019043): g, abdomen, lateral view; h, first pleopod; i, second pleopod. Scale bar = 1 mm for a, b, c, d; 1.1 mm for e, f, h, i; and 1.5 mm for g.

FIGURE 8. Zuzalpheus elizabethae, n. sp. Paratype male 2.7 mm (USNM 1019044): a, major first pereopod, dorsal view; b, same, lateral view; c, same, distal portion, lateral view; d, same, alternate view; e, same, tip of fixed finger, ventral view; f, minor first pereopod, lateral view; g, right second pereopod. Scale bar = 1 mm for a, b, c, d, e; and 0.7 mm for f, g.

FIGURE 9. Zuzalpheus elizabethae, n. sp. Paratype male 2.7 mm (USNM 1019044): a, right third pereopod; b, same, detail of distal portion; c, right fourth pereopod; d, same, detail of distal portion; e, right fifth pereopod; f, same, detail of distal portion. Scale bar = 1 mm for a, c, e; and 0.24 mm for b, d, f.

FIGURE 10. Zuzalpheus elizabethae, n. sp. Mouthparts. Paratype male 2.7 mm (USNM 1019044): 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. Scale bar = 1 mm for a, b, g; 2 mm for c, d, e; and 4 mm for f.