Elasmopus slatyeri, Lowry & Hughes, 2009

Lowry, J. K. & Hughes, L. E., 2009, Maeridae, the Elasmopus group *, Zootaxa 2260 (1), pp. 643-702 : 659-663

Elasmopus slatyeri sp. nov.

( Figs 9 , 10 )

Elasmopus pocillimanus . —J.L. Barnard, 1970: 130, figs 77, 78. —J.L. Barnard, 1971: 71, 75, figs 34, 35. — Ledoyer, 1972: 217, pl. 37. — Ledoyer, 1973: 52, 91.— Ledoyer, 1979b: 73. — Ledoyer, 1983: 478, fig. 180b. — Berents,

1983: 117, fig. 14. — Barnard & Barnard, 1983: 629 (in part). — Ren, 1998: 201, fig. 5. — Lowry & Stoddart, 2003: 178 (catalogue).

Type material. Holotype male, 4.9 mm, AM P30113, off western side of Palfrey Island , Lizard Island (14°40'S 145°28'E), reef rock, P.B. Weate & P.A. Hutchings, 12 January 1976 (76 LIZ 16 B) . Paratypes: 1 unsexed, AM P30111 (75 LIZ T-l) ; 1 male, 6.0 mm, AM P30112 (75 LIZ V-3) .

Type locality. Off western side of Palfrey Island, Lizard Island, Queensland, Australia (14°40'S 145°28'E) .

Etymology. This species is named for Cameron Slatyer who supported the Great Barrier Reef Amphipod Project from its inception and provided essential financial assistance for the Lizard Island Amphipod Workshop.

Description. Based on holotype, male, 4.9 mm, AM P30113.

Head. Head eyes ovate; lateral cephalic lobe broad, rounded, apically truncate, anteroventral margin with notch/slit, anteroventral corner rounded. Antenna 1 longer than antenna 2; peduncular article 1 subequal in length to article 2, without robust setae along posterior margin; accessory flagellum minute, with 3 articles (third tiny); flagellum with 5–6 articles. Antenna 2 peduncular article 4 longer than article 5; flagellum with 19 articles. Mandible incisor a smooth cutting edge with 2 apicomedial cusps; accessory setal row with 3 setae; palp well developed, 3-articulate; article 1 about as long as broad, shorter than article 2, inner margin not produced distally; article 2 subequal to article 3; article 3 short (2.7 x as long as broad) strongly falcate, longer than article 1.

Pereon. Gnathopod 1 coxa anteroventral corner produced, rounded, anterior margin concave; merus without posterodistal tooth; carpus about 2 x as long as broad; propodus palm acute, convex, defined by posterodistal corner, with posterodistal robust setae. Gnathopod 2 coxa posteroventral corner notch absent; basis slender; merus acutely produced distoventrally; carpus compressed, not enclosed by merus and propodus, length 0.67 x breadth; propodus expanded, with slender setae along posterior margin, palm acute, convex, smooth, palm about half length of propodus, without distomedial shelf, with group of 7 robust setae in shelf area, palmar margin without robust setae, without teeth, with long subpalmar seam, without posteroventral corner, without posterodistal robust setae; dactylus reaching end of palm, closing across medial surface of propodus, with 1 seta on anterior margin, with posteroproximal shelf, apically subacute. Pereopod 5 basis posterior margin slightly convex, without long slender setae, posteroventral corner broadly rounded; carpus and propodus without long, slender setae along anterior margin. Pereopod 6 basis posterior margin slightly convex, without long slender setae, posteroventral corner broadly rounded; merus and carpus not broadened; carpus and propodus without long, slender setae along anterior margin; propodus not expanded posterodistally. Pereopod 7 basis posterior margin slightly convex, smooth, without long slender setae, posteroventral corner broadly rounded; merus and carpus not broadened; propodus not expanded posterodistally.

Pleon. Pleonites 1–3 dorsally smooth, without dorsal setae, spines or carinae. Epimeron 1 posteroventral corner subquadrate. Epimeron 2 posteroventral corner subquadrate. Epimeron 3 posteroventral margin smooth, with posteroventral corner subquadrate. Urosomites 1–3 smooth, without dorsal spines or carinae. Uropod 1 peduncle with basofacial robust seta. Uropod 3 rami distally truncated; inner ramus short (length 2 x breadth), subequal in length to outer ramus; outer ramus longer than peduncle, 1-articulate. Telson moderately cleft (30 to 65%), as long as broad, lobes apically rounded, without dorsal robust setae, each lobe without apical/subapical robust setae, with 1 large robust seta on each outer margin.

Female (sexually dimorphic characters). Unknown.

Habitat. Marine epibenthic, living among coral and on coralline bottoms, in dead staghorn Acropora coral and reef rock covered with coralline algae Lithothamnion and Halimeda .

Remarks. Elasmopus pocillimanus Bate, 1862 was originally described from Genoa, Italy. The original description was sparse, but the text and illustrations of Karaman (1982) clearly define the species. It has regularly been reported from the Mediterranean Sea ( Della Valle 1893; Chevreux 1910; Chevreux & Fage 1925; Karaman 1982) and from the western Atlantic Ocean (see LeCroy 2000).

Berents (1983) reported E. pocillimanus from the Great Barrier Reef. We consider this taxon to be the new species, Elasmopus slatyeri sp. nov. This species is recognised by the male gnathopod 2 which lacks a distomedial shelf on the palm and has well developed subpalmar sculpturing and by the telson with two large, lateral, robust setae and apically rounded lobes without apical setae. These characters distinguish E. slatyeri from all other species of Elasmopus , including those on the GBR.

Elasmopus slatyeri has also been reported, as E. pocillimanus , from a number of places in the Indo-West Pacific: Hawaii (J.L. Barnard 1970, 1971); Madagascar ( Ledoyer, 1972, 1973, 1979 b, 1983); the Great Barrier Reef ( Berents, 1983); and South China Sea ( Ren 1998). Only the record of Schellenberg (1938) from Kiribati might be considered as E. pocillimanus , based on the illustration of the second gnathopod of a 6 mm male.

The adult material reported by J.L. Barnard (1970, 1971) from Hawaii is peculiar in that there is a tiny second article on the outer ramus of uropod.

Distribution. Australia. Queensland: Lizard Island ( Berents 1983). USA. Hawaiian Islands: Oahu (J.L. Barnard 1970, 1971).? Kiribati. ( Schellenberg 1938). Madagascar. Grand Récif de Tuléar ( Ledoyer 1972, 1983). South China Sea. Nansha (or Spratly) Islands ( Ren 1998).

Figures

FIGURE 9. Elasmopus slatyeri sp. nov., holotype, male, 4.9 mm, AM P30113, Lizard Island, Great Barrier Reef.

FIGURE 10. Elasmopus slatyeri sp. nov., holotype, male, 4.9 mm, AM P30113, Lizard Island, Great Barrier Reef.