Zuzalpheus androsi ( Coutière, 1909 ) 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 : 9-10

Zuzalpheus androsi ( Coutière, 1909) n. comb.

( Plate 1 )

Synalpheus androsi Coutière, 1909: 82 , fig. 50; Dardeau 1984:18; Ríos 2003: 45.

Material examined. ( 1) Holotype ♀ ( USNM 38409 ), 4.8 mm, Andros Island , Bahamas.

(2) 1 ♂, 2.1 mm ( VIMS 93 CBC4004), outer ridge of Carrie Bow Cay , Belize, 24 March 1993 in demosponge Pseudoceratina crassa ( Hyatt 1875) .

(3) 1 ♂, 3.2 mm ( VIMS 93 CBC5201), 1 ovigerous ♀, 3.5 mm ( VIMS 93 CBC5202), outer ridge of Carrie Bow Cay , Belize, 27 March 1993 in demosponge Hyattella intestinalis ( Lamarck 1814a) , 14 m .

(4) 2 ♀, 4.0 mm ( VIMS 99 CBC3801) and 3.8 mm (ovigerous, VIMS 99CBC3802) , 1 ♂, 3.6 mm ( VIMS 99 CBC3803), outer ridge of Carrie Bow Cay , Belize, 7 December 1999 in Hyattella intestinalis , 14 m .

(5) 1 ovigerous ♀, 4.6 mm ( VIMS 03 CBC0501), 1 ♂ , 4.0 mm ( VIMS 03 CBC0502), outer ridge of Carrie Bow Cay , Belize, 17 April 2003 in Hyattella intestinalis , 15 m.

Diagnosis. Body subcylindrical; carapace smooth, with pterygostomian corner produced into bluntly acute angle, posterior margin with cardiac notch distinct. Frontal region somewhat protruding over first segment of antennular peduncle, beyond commisure of stylocerite. Rostrum triangular, tip beveled, about as wide as ocular hoods, but slightly longer, and distally upturned. Orbitorostral process absent. Ocular hoods dorsally convex, bluntly acute, separated from rostrum by deep adrostral sinus. Ocular process nipple-shaped in lateral view, flanged posteriorly under eye. Ocellary beak in lateral view kidney-shaped. Stylocerite stout, mesial margin slightly concave, outer margin strongly convex; tip acute, not sharp, falling short of distal margin of first antennular peduncle; latter segment without ventromesial tooth, and with 2 basal ventral processes. Basicerite with obtuse dorsolateral corner, lateral spine clearly overreaching midlength of second segment of antennular peduncle. Scaphocerite blade absent; lateral spine acute, lateral margin slightly concave, usually 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, with ovoid profile; fingers shorter than half length of palm; fixed finger shorter than dactyl; in ventral view, fixed finger lacking conspicuous lateral protuberance. Palm of chela with distal superior margin produced into prominent bluntly acute tubercle. Merus extensor margin convex, with flat distal angular projection.

Minor pereopod 1 with palm less than two times longer than high; fingers shorter than palm; dactyl with flexor margin straight, blade-like, with obtuse emargination at midlength, and small subdistal bump parallel to dactyl axis; transverse dorsal setal combs on extensor surface of dactyl very conspicuous; fixed finger with flexor surface obliquely concave, and strongly convex keel behind apex. Carpus with conspicuous narrow ridge on interior margin. Extensor margin of merus almost straight, ending in obtuse angle.

Pereopod 2 with carpus 5-segmented, about as long as merus.

Pereopod 3 unique, dactyl biunguiculate, with flexor tooth thicker than extensor; propodus with distinctly concave flexor surface, defined by thin longitudinal crest or flange on posterior edge; carpus also with concave flexor surface between strong crest or flange on posterior edge and conspicuous longitudinal ridge on anterior edge; merus also with concave flexor surface and crest and ridge on distal half, matching those on carpus; coxa with mesial lamella. Pereopods 4 and 5 not modified.

Pleura 1 of male with ventroposterior corner acutely produced; pleura 2–5 broadly rounded to obtuse. Pleopod 1 of male with 3 terminal setae on endopod; pleopod 2 with marginal setae on exopod originating near midpoint; appendix interna present on male pleopods 2–5. Telson, space between posterior marginal spines greater than one-third width of posterior margin; margin with convex lobe; posterior corners adjacent to spines acute. Anal flaps, perianal setae, and postanal setal brush, absent. Uropods with single fixed tooth on outer margin of exopod anterior to, and slightly offset from, longer mobile spine, latter adjacent to internal tooth; diaeresis well developed across whole exopod.

Color ( Plate 1 ). Transparent with a faint hue of violet, most apparent on edges of abdomen. Edges of the distal portion of the major chela are translucent brown-green. The digestive gland and the ovaries are orangebrown. Mature embryos are brown, more intensely towards the center.

First larva. Hatching larvae (VIMS 99CBC4102), obtained in the laboratory, were large and exhibited the following characters: eyes not covered by carapace; antennule with three distinct segments and two flagella; antenna with fully developed blade on scaphocerite. First pair of pereopods with chelae; minor chela without the characteristic comb of setae on extensor surface. First to fourth pereopods with exopod. Pleopods biramous.

Hosts and ecology. Zuzalpheus androsi lives in heterosexual pairs, almost exclusively inside the demosponge Hyattella intestinalis at Carrie Bow Cay. On a few occasions we have collected single males inside Pseudoceratina crassa , Hymeniacidon caerulea Pulitzer-Finali 1986 , and probably also Agelas clathrodes . Such occasional records of single individuals are suspect because they may involve movement within clumps of rubble after collection. The eggs are large, fewer than 10 filling the brood chamber of a large ovigerous female.

Distribution. Western Atlantic: Andros Island, Bahamas ( Coutière 1909); Lee Stocking Island, Bahamas (K.S. Macdonald, pers. comm.); Belize Barrier Reef (this study).

Remarks. This species is remarkable in the unique structure of the carpus and merus of the third pereopod. It was previously known only from the female holotype, collected at Andros Island, Bahamas ( Armstrong 1949). We have found it to be common in the sponge Hyattella intestinalis on the outer ridge of the Belize Barrier Reef. In a male specimen from Carrie Bow Cay, there is a mobile spine in the cavity of the merus on the third pereopod. The description of the holotype ( Coutière 1909) mentions additional spines on the carpus, besides the distal one, which is present in our specimens, but our specimens do not have additional spines, only thick setae.

Figures

PLATE 1. Zuzalpheus agelas, male. (VIMS 04CBC4301) from Agelas clathrodes, Long Reef, Belize. Zuzalpheus androsi, female (VIMS 03CBC0901) from Hyattella intestinalis, Carrie Bow Cay, Belize. Zuzalpheus bousfieldi, female (VIMS 03CBC1201) from Hyattella intestinalis, Carrie Bow Cay, Belize. Zuzalpheus bousfieldi, male (VIMS 03CBC1202) from Hyattella intestinalis, Carrie Bow Cay, Belize. Zuzalpheus brevifrons, female (VIMS 03CBC3601) from unidentified sponge, Sand Bores, Belize. Zuzalpheus brooksi, female (VIMS 05FK14) from Spheciospongia vesparium, Key Largo, Florida, USA.