Ampithoidae and Maeridae Amphipods from Timor-Leste (Crustacea: Peracarida)

Quadrimaera metinaro sp. nov.

Figs 22–24

Type material. Holotype male, 3.5 mm, dissected, 4 slides, AM P.90577, east of Metinaro, Secret Garden Reef (8°29'15" S 125°49'53" E), 20 m, tufts of red algae, coll. L.E. Hughes, 22 September 2012 (TM 2012-060); paratype female, 5.0 mm, dissected, 1 slide, AM P.90578, east of Metinaro, Secret Garden Reef (8°29'15" S 125°49'53" E), 20 m, tufts of red algae, coll. L.E. Hughes, 22 September 2012 (TM 2012-060); paratypes 10 specimens, AM P.90595, east of Metinaro, Secret Garden Reef (8°29'15" S 125°49'53" E), 20 m, tufts of red algae, coll. L.E. Hughes, 22 September 2012 (TM 2012-060).

Type locality. East of Metinaro, Secret Garden Reef (8°29'15" S 125°49'53" E).

Etymology. Named from the type locality, applied as a noun in apposition.

Diagnosis. Gnathopod 2 propodus palm with subacute distal shelf, convex sinus and long rectangular tooth, distal shelf elevation higher than proximal tooth, palm defined by corner with well-developed tooth extending beyond palm margin; dactylus closing along palm with medial bulge. Epimera 1–3 with small acute tooth. Telson lobes distally concave with 4 long robust setae, setae subequal to telson length.

Description. Head lateral cephalic lobe subquadrate, anteroventral corner produced into a sharp cusp, lacking

anteroventral slit. Antenna 1 peduncular article 2 subequal to article 1; accessory flagellum with 7 articles. Antenna 2 gland cone reaching end of short article 3. Mandible palp article 3 longer than article 2.

Pereon. Gnathopod 1 coxa subquadrate; carpus rectolinear, length 1.1 times propodus; propodus subovate, palm convex, defined by rounded corner with one robust seta. Gnathopod 2 basis with anterodistal lobe well developed; ischium anterior margin with well-developed lobes; propodus rectangular with parallel margins, palm with subacute distal shelf, convex sinus and long rectangular tooth, distal shelf elevation higher than proximal tooth, palm defined by corner with well-developed tooth extending beyond palm margin; dactylus closing along palm with medial bulge. Pereopods 3–7 with bifid dactylus. Pereopods 5–7 basis narrow, proximally broader.

Pleon. Epimera 1–3 with small acute tooth. Uropod 3 peduncle 0.9 times rami length; inner ramus 1.1 times outer ramus; rami apically truncate with many long robust setae. Telson deeply cleft (80%), lobes distally concave with 4 long robust setae, setae subequal to telson length.

Female (sexually dimorphic characters). Based on 5.0 mm, AM P.90578.

Gnathopod 2 propodus palm with subacute distal shelf, convex sinus and long rectangular tooth, distal shelf elevation higher than proximal tooth, palm defined by corner with well-developed tooth extending beyond palm margin.

Remarks. Quadrimaera metinaro sp. nov. is similar to Q. serrata (Schellenberg, 1938) and Q. reishi (Barnard, 1970), these species have the gnathopod 2 propodus palm with a concave sinus in mature male specimens. In Q. metinaro

and Q. reishi the telson apical margin lobes have 4 long robust setae, while only 3 setae are present in Q. serrata. In Q. metinaro and Q. reishi the epimeron 3 posterior margin is smooth, whereas it is serrate in Q. serrata.

Quadrimaera metinaro sp. nov. can be separated from Q. reishi by the gnathopod 2 palm margin. The proximal palm margin is raised higher in Q. metinaro than the distal margin, while the opposite is seen in Q. reishi.