Elasmopus varanocephalensis, Lowry & Hughes, 2009

Lowry, J. K. & Hughes, L. E., 2009, Maeridae, the Elasmopus group *, Zootaxa 2260 (1), pp. 643-702 : 666-669

Elasmopus varanocephalensis sp. nov.

( Figs 13 , 14 )

Type material. Holotype, male, 8.0 mm, AM P78067, south of Lizard Head , Lizard Island (14°41’S 145°27’E), rubble, 2 m, J.D. Thomas, 29 January 1989 ( JDT / LIZ 14 c).

Type locality. South of Lizard Head , Lizard Island, Queensland, Australia (14°41’S 145°27’E) .

Etymology. Named for the type locality, Lizard Head.

Description. Based on holotype male, 8.0 mm, AM P78067.

Head. Head eyes ovate; lateral cephalic lobe broad, truncated, 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; article 2 longer than article 3; accessory flagellum short, with 4 articles; flagellum with 21 articles. Antenna 2 peduncular article 4 subequal in length to article 5; flagellum with 9 articles. Mandible incisor a smooth cutting edge with 2 apicomedial cusps; accessory setal row with 2 setae; palp well developed, 3-articulate; article 1 about as long as broad, shorter than article 2, inner margin not produced distally; article 2 shorter than article 3; article 3 long (4 x as long as broad), weakly 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, carpus subequal in length to propodus; propodus with setae in anterodistal bunches and along posterior margin; propodus palm acute, slightly convex, entire, defined by posterodistal corner, with posterodistal robust setae. Gnathopod 2 coxa posteroventral corner notch absent; basis slender; merus with subquadrate distoventral corner; carpus compressed, projecting between merus and propodus, length 1 x breadth; propodus expanded, without setal bunches along posterior margin, palm acute, slightly convex, slightly sculptured, palm about one third length of propodus, with reduced subtriangular distomedial shelf, with 6 robust setae on shelf, without midmedial excavation, palmar margin lined with a row of 6 robust setae, without teeth, subpalmar surface with short proximal subpalmar seam forming two nodules, without posteroventral corner, with posterodistal robust setae; dactylus reaching end of palm, closing along palm, without setae on anterior margin, without posteroproximal shelf, apically blunt. Pereopod 4 coxa posteroventral lobe slightly developed, with rounded posteromedial corner. Pereopod 5 basis slightly expanded, posterior margin straight, without long slender setae, posteroventral corner narrowly subquadrate; carpus and propodus without long, slender setae along anterior margin. Pereopod 6 basis posterior margin straight, minutely castelloserrate, without long slender setae, posteroventral corner narrowly rounded; carpus and propodus without long, slender setae along anterior margin; merus and carpus not broadened; propodus slightly expanded posterodistally to from a hood-like projection. Pereopod 7 basis posterior margin convex, with posterior margin minutely castelloserrate, not produced posterodistally, without long slender setae, posteroventral corner broadly rounded; merus and carpus not broadened; propodus expanded posterodistally to from a hood-like projection.

Pleon. Pleonites 1–3 dorsally smooth, without setae, spines or carinae. Epimeron 1 posteroventral corner with small acute spine. Epimeron 2 posteroventral corner with small acute spine. Epimeron 3 ventral margin smooth, posteroventral margin smooth, posteroventral corner with small acute spine. Urosomites 1–3 dorsally smooth, without setae, spines or carinae. Uropod 1 peduncle with basofacial robust seta. Uropod 3 rami distally rounded, apical robust setae long or short; inner ramus subequal in length to outer ramus; inner ramus long (length 2 to 2.5 x breadth); outer ramus short, length 2.2 x breadth, longer than peduncle, 1-articulate. Telson deeply cleft (more than 66%), longer than broad, tapering distally, each lobe with long inner and short outer apical cusps, apical conical extension reaching at least halfway along longest seta, without dorsal robust setae, with apical/subapical robust setae, each lobe with 2 long and short apical robust setae, without robust setae on outer and inner margins.

Female (sexually dimorphic characters). Unknown.

Habitat. Marine, epibenthic, living in coral rubble.

Remarks. Elasmopus varanocephalensis sp. nov. is most similar to E. alalo Myers, 1986b , E. spinicarpus Berents, 1983 and E. seticarpus Myers, 1985 . All of these species have an elongate, deeply cleft telson with short subapical setae and a relatively plain palm on male gnathopod 2. Elasmopus varanocephalensis differs from E. alalo in having a very reduced distomedial shelf, no midmedial excavation, a single row of robust setae on the palm and two subpalmar nodules of male gnathopod 2. It differs from E. spinicarpus in the presence of a weak posterodistal shelf on male gnathopod 2. Although the palms are more similar between E. varanocephalensis and E. seticarpus , the extremely setose carpus of male gnathopod 2 in E. seticarpus distinguishes these species.

Distribution. Australia. Queensland: Lizard Island (current study).

Figures

FIGURE 13. Elasmopus varanocephalensis sp. nov., holotype, male, 8.0 mm, AM P78067, Lizard Island, Great Barrier Reef.

FIGURE 14. Elasmopus varanocephalensis sp. nov., holotype, male, 8.0 mm, AM P78067, Lizard Island, Great Barrier Reef.