Synalpheus irie, Iii, Kenneth S Macdonald, Hultgren, Kristin & Duffy, Emmett, 2009

Iii, Kenneth S Macdonald, Hultgren, Kristin & Duffy, Emmett, 2009, The sponge-dwelling snapping shrimps (Crustacea, Decapoda, Alpheidae, Synalpheus) of Discovery Bay, Jamaica, with descriptions of four new species, Zootaxa 2199, pp. 1-57 : 25-32

Synalpheus irie n. sp.

Figures 11–16 , Color plate 3C,D

Material examined. Holotype: non-ovigerous individual, CL: 4.88 mm, ( USNM 1126365, original VIMS 08JAM3602), fore-reef (near M1 channel marker), (18° 28.083΄ N, 77° 23.289΄ W), from canals of Auletta cf. sycinularia Schmidt. Allotype : ovigerous female, CL: 5.33 mm, ( USNM 1126366, original VIMS 08JAM3601), fore-reef (near M1 channel marker), from canals same of same individual Auletta cf. sycinularia as holotype. Paratypes: non-ovigerous individual, CL: 4.88 mm, ovigerous female, CL: 5.10 mm, ( USNM 1126367, 1126368, original VIMS 08JAM 2801-02), Dairy Bull Reef, Discovery Bay, (18° 28' 20.6 N, 77° 24' 36.4 W), from canals of Auletta cf. sycinularia . MaxCL ovigerous female: 5.33 mm. MaxCL nonovigerous individual: 4.88 mm.

Description. Body form subcylindrical; carapace smooth, sparsely setose, posterior margin with cardiac notch distinct. Rostrum shorter and narrower than ocular hoods ( Fig. 11 ). Ocular hoods dorsally convex; in dorsal view, blunt, separated from rostrum by adrostral sinus. Stylocerite acute, with sharp tip; mesial and lateral margins concave; reaching almost to distal margin of first segment of antennular peduncle. First antennular segment without ventromesial tooth, and with two basal ventral processes. Basicerite with acute angle on dorsomesial corner, with longer ventrolateral spine; reaching midpoint of second segment of antennular peduncle, ~60% length of scaphocerite. Scaphocerite blade narrow, slightly shorter than basicerite, acute lateral spine robust, with lateral margin concave; reaching beyond third segment of antennular peduncle. Third maxilliped ( Fig. 13 ) with distal circlet of approximately six spines on distal segment, without ventrodistal spine on antepenultimate segment.

Major first pereopod ( Fig. 11 , 12 ) massive, fingers clearly shorter than half length of palm; fixed finger ~75% length of dactyl. Fingers strongly curved dorsally. Palm of chela almost twice as wide distally as at base. Superior margin of palm with distinct distal two-pronged protuberance consisting of an elongated sharp spine closer to fingers and a rounded prominence on outside (i.e. lateral to spine in life position of chela). Minor first pereopod ( Fig. 13 ) with palm clearly less than two times longer than high; fingers clearly shorter than palm; dactyl with flexor margin concave, blade-like, with large, distinct second tooth basal and subequal in length to tip; extensor surface of dactyl with thick brush of curved setae; fixed finger with flexor margin straight, blade-like, with small but distinct tooth proximal to tip.

Second pereopod ( Fig. 14 ) with carpus 5-segmented, subequal in length to merus. Both fingers terminating in a narrow, curved tooth.

Third pereopod ( Fig. 14 ) slender; dactyl biunguiculate, with flexor and extensor unguis subequal in thickness, mesial margin of flexor unguis strongly convex; propodus with row of six movable spines on flexor margin and one pair of distal movable spines flanking base of dactyl; carpus without distal movable spine on flexor margin; merus almost four times longer than wide, without movable spines on flexor margin. Fourth pereopod ( Fig. 14 ) similar to third, carpus with distal movable spine on flexor margin. Fifth pereopod ( Fig. 14 ) weaker than fourth; propodus with three spines on flexor margin, and six transverse combs of stout setae on ventral face; carpus without distal spine.

First pleura ( Fig. 13 ) of male with posterior corner distinctly produced ventrally into short, broad, anteriorly directed hook; second through fourth pleura of male slightly concave ventral margin, anterior corners rounded, posterior corners subacute.

First pleopod ( Fig. 15 ) of male with 2 terminal setae on endopod; second pleopod of male with marginal setae on exopod originating in distal third; appendix interna present on second to fifth male pleopods. Second pleopod ( Fig. 12 ) of female with marginal setae on exopod originating in distal third; appendix interna present on second to fifth female pleopods.

Telson ( Fig. 13 , 16 ) with convex marginal lobe present; posterior corners adjacent to spines obtuse. Space between distal spines 50% of distal margin, lateral spines ~60% length of mesial. Distal margin with fan of 8 plumose setae between spines. Distal margin ~40% width of proximal margin. Dorsal spines strong, emanating from prominent longitudinal ridges ( Fig. 13 ). Uropods (fig 13, 16) with a single fixed tooth on lateral margin of exopod distinctly removed anteriorly from the movable one, the latter extremely long, slender, and curved.

Color. Nondescript, translucent with orange tinge to thickened parts of cuticle; distal 1/4 of palm and fingers of major chela bright orange with split white crescent spanning palm near fingers; ovaries and embryos green.

Etymology. We have named this species in honor of the nation in which it was found. The word “ irie ” is a Rastafari term referring to that which is good and peaceful.

Variation. Length of lateral distal spine of telson ranges from 25% length of mesial spine to 75% of mesial spine.

Hosts and ecology. Both pairs of Synalpheus irie , n. sp. were collected from the canals of Auletta cf. sycinularia .

Distribution. Jamaica (this study).

Remarks. Synalpheus irie , n. sp. is easily distinguishable from all other west Atlantic Synalpheus species by its distinctive major chela. The short fingers that curve dorsally almost into a bowl-shape, and the twopronged distal superior marginal protuberance are both unique within the genus in this region. The distinctive curved movable spine on the outer uropod is similar to that found in other Synalpheus species, but appears to be unique among members of the S. gambarelloides group. However, the presence of a thick brush of setae on the minor chela dactyl, as well as the triangular shape of the telson, firmly places S. irie within the S. gambarelloides group. With its curved major chela fingers, fan of setae on the distal margin of the telson, and antennal characters, this new species most closely resembles Synalpheus mcclendoni , but it is easily distinguished by the characters listed previously.

Figures

FIGURE 11. Synalpheus irie n. sp. Holotype non-ovigerous individual CL: 4.88 mm (USNM 1126365, original VIMS 08 JAM 3602) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: A, carapace, anterior region, and cephalic appendages, dorsal view; B, chela of major first pereopod, ventral view; C, same, mesial view. Allotype ovigerous female CL: 5.32 mm (USNM 1126366, original VIMS 08 JAM 3601) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: D, carapace, anterior region, and cephalic appendages, dorsal view; E, chela of major first pereopod, anterior region, ventral view. Scale bar = 0.75 mm for A, D; 1 mm for E; 1.25 mm for B, C.

FIGURE 12. Synalpheus irie n. sp. Paratype non-ovigerous individual CL: 4.88 mm (USNM 1126367, original VIMS 08 JAM 2801) from Auletta cf. sycinularia, fore-reef, Discovery Bay, Jamaica: A, carapace, anterior region, and cephalic appendages, dorsal view; B, chela of major first pereopod, anterior region, lateroventral view. Paratype ovigerous female CL: 5.10 mm (USNM 1126368, original VIMS 08 JAM 2802) from Auletta cf. sycinularia, fore-reef, Discovery Bay, Jamaica: C, carapace, anterior region, and cephalic appendages, dorsal view; D, chela of major first pereopod, anterior region, mesial view; E, same, ventral view; F, same, detail of distal superior margin protuberance. Scale bar = 0.75 mm for A, B, C, D, E; 0.4 for F.

FIGURE 13. Synalpheus irie n. sp. Holotype non-ovigerous individual CL: 4.88 mm (USNM 1126365, original VIMS 08 JAM 3602) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: A, chela of minor first pereopod, setae removed, lateral view; B, same, detail of distal region, mesial view; C, abdomen, right uropod, and telson, lateral view; D, third maxilliped; E, same, detail of distal region. Scale bar = 0.75 mm for A; 0.33 mm for B, 1 mm for C; 0.5 mm for D; 0.15 mm for E.

FIGURE 14. Synalpheus irie n. sp. Holotype non-ovigerous individual CL: 4.88 mm (USNM 1126365, original VIMS 08 JAM 3602) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: A, second pereopod; B, third pereopod; C, same, detail of distal region; D, fourth pereopod; E, same, detail of distal region; F, fifth pereopod; G, same, detail of distal region. Scale bar = 0.5 mm for A, B, D, F; 0.15 for C, E, G.

FIGURE 15. Synalpheus irie n. sp. Holotype non-ovigerous individual CL: 4.88 mm (USNM 1126365, original VIMS 08 JAM 3602) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: A, first pleopod; B, second pleopod. Allotype ovigerous female CL: 5.32 mm (USNM 1126366, original VIMS 08 JAM 3601) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: C, first pleopod; D, second pleopod. Scale bar = 0.33 mm.

FIGURE 16. Synalpheus irie n. sp. Holotype non-ovigerous individual CL: 4.88 mm (USNM 1126365, original VIMS 08 JAM 3602) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: A, left uropod and telson, dorsal view; B, telson, dorsal view, detail of distal margin. Allotype non-ovigerous individual CL: 5.32 mm (USNM 1126366, original VIMS 08 JAM 3601) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica: C, left uropod and telson, dorsal view. Paratype ovigerous female 5.10 mm (USNM 1126368, original VIMS 08 JAM 2802) from Auletta cf. sycinularia, fore-reef, Discovery Bay, Jamaica: D, telson, dorsal view. Scale bar = 0.5 mm for A, C, D; 0.25 for B.