Synalpheus corallinus, 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: 16-22
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Synalpheus corallinus n. sp.
Material examined. Jamaica: Holotype: non-ovigerous individual, CL: 3.40, ( USNM 112363, original VIMS 08JAM 7002), Dairy Bull Reef, (18 ° 28.083 ΄ N, 77 ° 23.289 ΄ W), from canals of Hyattella intestinalis . Allotype: ovigerous female, CL: 3.93 mm, ( USNM 112364, original VIMS 08JAM 7001), Dairy Bull Reef, from canals of same individual H. intestinalis as holotype.
Description. Body form subcylindrical; carapace smooth, sparsely setose, posterior margin with cardiac notch distinct. Frontal margin very shallow, rostrum slightly longer than ocular hoods ( Fig. 5 View FIGURE 5 ). Orbitorostral process absent. Ocular hoods dorsally convex; in dorsal view, blunt, separated from rostrum by shallow adrostral sinus. Stylocerite acute, with blunt tip; mesial margin concave; reaching midpoint of first segment of antennular peduncle. First antennular segment without ventromesial tooth, and with two basal ventral processes. Basicerite without sharp tooth on dorsomesial corner, with longer ventrolateral spine, not reaching third segment of antennular peduncle. Scaphocerite blade absent, acute lateral spine robust, with lateral margin slightly concave, slightly longer than basicerite spine, barely reaching third segment of antennular peduncle. Third maxilliped ( Fig. 6 View FIGURE 6 ) with distal circlet of approximately six spines on distal segment, without ventrodistal spine on antepenultimate segment.
Major first pereopod ( Fig. 5 View FIGURE 5 ) massive, fingers clearly shorter than half-length of palm; fixed finger slightly shorter than dactyl. Palm of chela with distal superior margin protuberance tapering distally and slightly curved downward, toward dactyl. Minor first pereopod ( Fig. 7 View FIGURE 7 ) with palm less than two times longer than high; fingers clearly shorter than palm; dactyl with flexor margin concave, blade-like, with two distinct distal teeth, subequal in length; extensor surface of dactyl with two closely set longitudinal rows of curved setae; fixed finger with flexor margin slightly concave, blade-like, and two distinct distal teeth subequal in length.
Second pereopod ( Fig. 8 View FIGURE 8 ) with carpus 5 -segmented, subequal in length to merus. Both fingers terminating in a narrow, curved tooth.
Third pereopod ( Fig. 8 View FIGURE 8 ) slender; dactyl biunguiculate, with flexor unguis clearly thicker than extensor, mesial margin of flexor unguis strongly convex; propodus with row of five movable spines on flexor margin and one pair of distal movable spines flanking base of dactyl; carpus with distal movable spine on flexor margin; merus almost four times longer than wide, without movable spines on flexor margin. Fourth pereopod ( Fig. 8 View FIGURE 8 ) similar to third, slightly weaker; three spines on flexor margin of propodus. Fifth pereopod ( Fig. 8 View FIGURE 8 ) weaker than fourth; propodus with only two spines on flexor margin, and four transverse combs of stout setae on ventral face; carpus without distal spine.
First pleura ( Fig. 6 View FIGURE 6 ) of male with posterior corner distinctly produced ventrally into strong hook; second pleura of male broadly rounded with slightly concave ventral margin; third to fifth pleura of male with rounded anterior corner, slightly obtuse posterior corner.
First pleopod ( Fig. 9 View FIGURE 9 ) of male with single terminal seta on endopod; second pleopod of male with marginal setae on exopod originating in distal half; appendix interna present on second to fifth male pleopods. Second pleopod ( Fig. 7 View FIGURE 7 ) of female with marginal setae on exopod originating in distal half; appendix interna present on second to fifth female pleopods.
Telson ( Figs. 5 View FIGURE 5 , 6 View FIGURE 6 ) with convex marginal lobe on distal margin; posterior corners adjacent to spines obtuse. Dorsal spines large, clearly removed from lateral margins. Posterior margin with six setae between two sets of spines, lateral spines half-length of mesial. Distance between distal spines 30 % width of distal margin. Telson 30 % as wide at distal margin as at base. Uropods ( Fig. 6 View FIGURE 6 ) with a single fixed tooth on lateral margin of exopod distinctly removed anteriorly from movable spine, latter much longer than adjacent posterior fixed tooth.
Color in life. Nondescript, translucent with dull gold tinge to thickened parts of cuticle; distal palm and fingers of major chela brownish; ovaries and embryos orange-tinged pink (Plate 2 D).
Etymology. We have named this species after the highly distinctive embryo color, which most closely matches “coral pink” from the ISCC-NBS Dictionary of Color Names ( Kelly & Judd 1976).
Variation. There is little variation between the two specimens of Synalpheus corallinus we examined. The dactyl of the female’s major chela ( Fig. 5 View FIGURE 5 ) is distally acute, rather than rounded as in the male. Additionally, the frontal margin ( Fig. 5 View FIGURE 5 ) of the female is shallower than that of the male, and the relative lengths of the lateral spines of the basicerite and scaphocerite differ between these individuals.
Distribution. Presently known only from Discovery Bay, Jamaica.
Remarks. Synalpheus corallinus n. sp. appears to be another member of the complex of closely related, morphologically similar species that includes S. brooksi , S. bousfieldi , S. chacei , S. thele n. sp. and S. plumosetosus n. sp. (see Table 3). Synalpheus corallinus is distinguished by the combination of very shallow frontal margin, two parallel longitudinal rows of setae on the dactyl of the minor chela, protuberance on the major chela palm tapered and curved downward distally, and distinctive coral-colored embryos and ovaries (Color Plate 2 D). While most of these individual characters are shared with one or more members of the S. brooksi complex, such as shallow frontal margin and minor chelae setal brush ( S. chacei , S. thele ), and the shape of the major chela protuberance ( S. bousfieldi , S. plumosetosus ), Synalpheus corallinus exhibits a unique combination of these characters.
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