Nagada uwedoae Lowry & Stoddart 1995

Nagada uwedoae Lowry & Stoddart, 1995

(Figs 5, 6)

Nagada uwedoae Lowry & Stoddart, 1995: 154, figs 34–36. –– Lowry & Stoddart, 2003: 282 (catalogue).

Type locality. Outer Barrier between Dam Awan (Rasch Passage) and Wongad Island, Astrolabe Bay, Papua New Guinea (5°08.59’S 145°49.65’E), 290 m depth.

Material examined. 1 ovigerous female, AM P69472 (JML 81/26-11-4); 48 specimens AM P69474 (QLD 630); 3 specimens AM P69475 (QLD 631); 1 specimen AM P69476 (QLD 671); 22 specimens AM P69477 (QLD 673); 16 specimens AM P69478 (QLD 748); many specimens AM P69480 and 1 female, AM P78943 (QLD 766); many specimens, AM P69479 (QLD 767); many specimens, AM P69481 (QLD 775); 5 specimens, AM P50744 (QLD 952); 11 specimens, AM P51116 and 2 specimens, AM P52655 (QLD 953); 127 specimens, AM P51120 and 8 specimens, AM P58342 (QLD 954); 285 specimens, AM P50746 (QLD 955/ SEAS); 28 specimens, AM P57616 (QLD 1055); 11 specimens, AM P50754 (QLD 1073); 16 specimens, AM P51123 (QLD 1075); 105 specimens, AM P50757 (QLD 1076); 154 specimens, AM P51121 (QLD 1078); 8 specimens, AM P50760 (QLD 1093); 45 specimens, AM P50762 (QLD 1096).

Description. Based on ovigerous female (2 eggs), 2.5 mm, AM P69472 and female, 3.2 mm, AM P78943.

Head and body. Body without dorsal carina. Head lateral cephalic lobes rounded, with apically rounded margins; eyes ovate. Antenna 1 subequal to antenna 2; peduncle article 1 not produced, peduncular article 1 without anterodistal lobe, without posterodistal spine; article 2 short, without anterodistal lobe or posterodistal spine; article 3 short; flagellum with weak 2-field callynophore, robust setae absent on proximal articles, calceoli absent; accessory flagellum with 3 articles. Antenna 2 less than 40% of body length; peduncle without brush setae, calceoli absent. Epistome / upper lip fused, weakly sinuous. Mandible molar a setose tongue; palp attached midway, article 3 without A3-setae. Maxilla 1 outer plate with setal-teeth in 7/4 crown arrangement (see Remarks); setal-tooth 7, left and right symmetrical, cuspidate distally; palp distal margin with apical robust setae and serrations. Maxilliped inner plates poorly developed, not reaching half the length of the outer plate; outer plates without apical robust setae; palp 4-articulate, article 4 well developed.

Pereon. Gnathopod 1 simple; coxa large, about as long as coxa 2, subrectangular with straight anterior margin; basis without setae along anterior margin; ischium long (length 2.4 x breadth); carpus long (length 2.2 x breadth), distinctly longer than propodus, without posterior lobe; propodus margins tapering; dactylus complex, with 2 large subterminal spines and row of short spines along posterior margin. Gnathopod 2 chelate; carpus longer than (1.7 x) propodus; palm obtuse; dactylus minute. Pereopod 4 coxa with well developed posteroventral lobe. Pereopod 5 coxa equilobate; basis distinctly longer than broad. Pereopod 7 basis posterodistally produced.

Pleon. Epimeron 3 posterodistal corner rounded. Urosomite 1 with anterodorsal notch and slightly rounded boss. Uropod 1 rami subequal. Uropod 2 rami subequal, inner ramus with slight marginal constriction. Uropod 3 without plumose setae on rami; outer ramus 2-articulate, article 2 long, inner ramus extending beyond article 1 of outer ramus. Telson subequal in length and breadth, entire, without dorsal robust setae, with 2 apical robust setae.

Male (sexually dimorphic characters). Based on paratype male, 2.1 mm, AM P41607. Antennae 1–2 with calceoli. Antenna 1 flagellum with strong 2-field callynophore.

Habitat. Scavenger living on muddy bottoms from the littoral to the continental slope, in 15 to 500 m depth.

Remarks. The illustrated specimen has the uropod 3 inner ramus slightly shorter than the outer ramus; in the holotype the rami are subequal. We have seen some variation in the relative lengths of these rami but the inner ramus is always longer than article 1 of the outer ramus and always shorter than the entire outer ramus. The presence of 12 setal-teeth on the maxilla 1 outer plate of the illustrated specimen seems to be an individual aberration. Other Australian specimens have the normal 11 setal-teeth in a 7/4 crown arrangement. Nagada uwedoae occurs from northern Papua New Guinea along the east coast of Australia from the northern Great Barrier Reef to Tasmania (Lowry & Stoddart 1995, 2003). It can be separated from other lysianassoid species on the GBR by the combination of head and body without scattered setae, gnathopod 1 simple and the posteroventral corner of the third epimeron broadly rounded.

Distribution. Australia. Queensland: Ashmore Reef, Boot Reef, Great Detached Reef, Portlock Reef (current study); Lizard Island (current study). New South Wales (Lowry & Stoddart 2003). Tasmania (Lowry & Stoddart 2003). Papua New Guinea. Astrolabe Bay (Lowry & Stoddart 1995).