Wallametopa cabon J.L. Barnard, 1974

Krapp-Schickel, Traudl, 2009, Stenothoidae *, Zootaxa 2260 (1), pp. 872-879 : 875-878

Wallametopa cabon J.L. Barnard, 1974

( Figs 3 , 4 , Pl. 6C, D)

Wallametopa cabon J.L. Barnard, 1974: 132 , figs 82, 83. — Ledoyer, 1979: 132, fig. 85. — Ledoyer, 1986: 977, fig. 386.

Material examined. 1 female, 2.4 mm AM P71316 (QLD 1782); 1?male, 2.0 mm AM P71326 (QLD 1780), both from North Point , Lizard Island (14°38.760’S 145°27.31’E) .

Type locality. Western Port , Victoria, Australia (~ 38°22'S 145°20'’E) .

Description. Based on female, 2.4 mm, AM P71316.

Head. Eyes large. Antenna 1 long (distinctly longer than head and pereonites 1–4), distinctly longer than antenna 2; peduncle not geniculate; peduncular article 1 without anterodistal lobe, without posterodistal lobe; peduncular article 2 without anterodistal lobe; flagellum 14-articulate; accessory flagellum present and minute, 1 - articulate (hidden under distal margin of peduncular article 3). Mandible palp 1-articulate, very short. Maxilla 1 palp 1-articulate, about 3–4 times as long as wide. Maxilla 2 plates not sitting one upon the other, but next to each other, inner plate distinctly shorter than outer one.

Pereon. Pereonite 4 similar in length to pereonite 3, without dorsal carina. Gnathopods 1–2 dissimilar in shape. Coxa 1 subquadrate. Gnathopod 1 simple; merus not enlarged or produced distally; carpus elongate, wider distally than proximally; propodus 3–4 x as long as broad; dactylus outer margin with many robust setae. Gnathopod 2 propodus oblique/rounded, with posterodistal expansion, about 2 x as long as broad, not transverse, posterior margin without or with scarcely developed corner, evenly rounded, crenulate along most of the palmar margin, with scattered or no fine setae; dactylus reaching distinctly further than half length of propodus, posterior margin not or minutely serrate. Pereopod 3 coxa rectangular. Pereopod 4 coxa ventral margin convex. Pereopod 5 basis not expanded. Pereopod 6, 7 basis fully expanded; merus distally twice as wide as ischium, with row of robust setae on posterior margin, expansion reaching to or past mid length of carpus; dactylus large (subequal or longer than carpus).

Pleon. Pleonite 3 without dorsal elevation. Epimeron 3 posteroventral corner produced, subacute. Urosomites free. Urosomite 1 without dorsal carina. Uropod 1 peduncle without a distoventral spine; inner ramus well developed, subequal in length to outer ramus. Uropod 2 inner ramus well developed, longer than outer ramus. Uropod 3 with peduncle and single ramus; ramus subequal to peduncle; ramus 2–articulate, article 2 subequal in length or longer than article 1. Telson laminar, with dorsolateral robust setae, apically acute or subacute.

Male (sexually dimorphic characters). Based on? male 2.0 mm AM P71326. Stridulation with scarce ridges on coxa 4; coxa 3 without stridulation ridges.

Habitat. Marine. Hydroids, granite rock face with some corals and turf algae, 6– 11 m.

Remarks. This species seems to have a wide distribution. It was described first from Victoria (J.L. Barnard 1974), based on 8 specimens found in 7 samples. The only other report of the species is from Madagascar ( Ledoyer 1979). The material from Australia and Madagascar shows no significant morphological differences. In present material, some length ratios do not match perfectly with the type material (maxilla1 palp is somewhat shorter, pereopod 7 basis somewhat smaller), but due to the small sample size these differences cannot be evaluated.

Distribution. Australia. Queensland: Lizard Island (current study). Victoria: Western Port (J.L. Barnard 1974). Madagascar ( Ledoyer 1986).

Figures

FIGURE 3. Wallametopa cabon J.L. Barnard, 1974, female, 2.4 mm, AM P71316, North Point, Lizard Island, Great Barrier Reef.

FIGURE 4. Wallametopa cabon J.L. Barnard, 1974, female, 2.4 mm, AM P71316, North Point, Lizard Island, Great Barrier Reef.