Pseudambasia acuticaudata ( Ledoyer, 1984 )

Lowry, J. K. & Stoddart, H. E., 2009, Lysianassidae *, Zootaxa 2260 (1), pp. 561-597 : 565-568

Pseudambasia acuticaudata ( Ledoyer, 1984)

( Figs 3 , 4 , Pl. 4C)

Parambasia acuticaudata Ledoyer, 1984: 84 , fig. 41. — Barnard & Karaman, 1991: 514. — Lowry & Stoddart, 1994: 182.

Pseudambasia acuticaudata . — Lowry & Stoddart, 1995: 113, figs 8, 9.

Material examined. 1 unsexed, AM P68838 ( FNQ 79-26 ) ; 7 unsexed, AM P68850 ( JDT / LIZ 15 ) ; 1 male, AM P68860 ( JML 20-10 - 2 ) ; 7 unsexed, AM P68859 , 1 female, ovigerous (3 eggs), 2.5 mm, AM P68938 and 1 male, AM P68939, ( JML 81 /26-11-4) ; 1 unsexed, AM P68812 ( NCL 110 ) ; 1 unsexed, AM P68813 ( NCL 156 ) ; 2 unsexed, AM P68831 ( NT 3 ) ; 1 unsexed, AM P68832 ( NT 24 ) ; 2 unsexed, AM P68833 ( NT 25 ) ; 1 unsexed, AM P68834 ( NT 26 ) ; 6 unsexed, AM P68835( NT 55 ) ; 1 unsexed, AM P68836 ( NT 66 ) ; 1 unsexed, AM P68837 ( NT 76 ) ; 5 unsexed, NTM ( PD 1 ); 2 unsexed, NTM ( PD 2 ); 6 unsexed, NTM ( PD 3 ); 3 unsexed, NTM ( PD 4 ); 4 unsexed, NTM ( PD 5 ); 4 unsexed, NTM ( PD 6 ); 3 unsexed, NTM ( PD 7 ); 13 unsexed, NTM ( PD 8 ); 1 unsexed, NTM ( PD 9 ); 16 unsexed, NTM ( PD 10 ); 7 unsexed, NTM ( PD 11 ); 1 female, AM P68846 ( QLD 25 ) ; 1 ovigerous female, AM P68847 ( QLD 35 ) ; 1 male, AM P68845 ( QLD 48 ) ; 1 unsexed, AM P68841 ( QLD 87 ) ; 1 unsexed, AM P68842 ( QLD 88 ) ; 1 unsexed, AM P68843 ( QLD 90 ) ; 1 unsexed, AM P68844 ( QLD 91 ) ; 2 unsexed, AM P68839 ( QLD 94 ) ; 2 unsexed, AM P68840 ( QLD 95 ) ; 1 unsexed, AM P68848 ( QLD 103 ) ; 1 unsexed, AM P71932 ( QLD 1350 ) ; 1 unsexed, AM P71933 ( QLD 1364 ) ; 1 unsexed, AM P70676 and 2 unsexed, AM P70687 ( QLD 1641 ) ; 1 unsexed, AM P70694 ( QLD 1636 ) ; 2 unsexed, AM P70713 ( QLD 1636 ) ; 6 unsexed, AM P71180 ( QLD 1730 ) ; 2 unsexed, AM P71158 ( QLD 1732 ) ; 1 unsexed, AM P71094 ( QLD 1733 ) ; 2 unsexed, AM P71166 ( QLD 1751 ) ; 3 unsexed, AM P71292 ( QLD 1763 ) ; 3 unsexed, AM P71470 ( QLD 1792 ) ; 1 unsexed, AM P71361 ( QLD 1800 ) ; 2 unsexed, AM P71460 ( QLD 1803 ) ; 2 unsexed, AM P71401 ( QLD 1806 ) ; 1 unsexed, AM P71414 ( QLD 1815 ) ; 1 unsexed, AM P75694 ( QLD 1863 ) ; 1 unsexed; AM P75695 ( QLD 1873 ) ; 1 unsexed, AM P78687 ( QLD 1889 ) ; 8 unsexed, AM P75693 ( QLD 1979 ) ; 5 unsexed, AM P75691 ( QLD 1983 ) ; 1 unsexed, AM P75692 ( QLD 1988 ) .

Type locality. Îlot Maître , Southwestern Lagoon, New Caledonia, western South Pacific Ocean (~ 22°16’S 166°26’E) .

Description. Based on female, 2.5 mm, AM P68938 and male, P68939.

Head and body. Body without dorsal carina. Head lateral cephalic lobes rounded, with apically rounded margins; eyes round. Antenna 1 subequal to antenna 2; flagellum article 1 slightly longer than article 2; without callynophore, robust setae absent from proximal articles; calceoli absent; accessory flagellum with 2 articles. Antenna 2 less than 40% of body length; peduncular article 3 elongate, at least three times as long as broad; calceoli absent. Mouthparts forming a subquadrate bundle. Mandible molar absent; palp attached extremely proximally, article 3 without A3–setae. Maxilla 1 outer plate with setal-teeth in 6/5 arrangement; setal-tooth 7, left and right symmetrical, cuspidate distally along inner margin; palp distal margin with serrations. Maxilliped inner plates well developed, greater than half the length of outer plate; outer plates without apical robust setae; palp 4–articulate, article 4 well developed.

Pereon. Gnathopod 1 weakly subchelate; coxa large, about as long as coxa 2, subrectangular with slightly concave anterior margin; basis sparsely setose along anterior margin; ischium short; carpus short (length 1.7 x breadth), subequal in length to propodus, without posterior lobe; propodus longer than broad, margins tapering, palm extremely acute, slightly excavate; dactylus inner margin not serrated. Gnathopod 2 subchelate; carpus twice as long as propodus; palm transverse; dactylus minute. Pereopod 4 coxa with well developed posteroventral lobe. Pereopod 5 coxa equilobate; basis about as long as broad.

Pleon. Epimeron 3 posterior margin smooth, posterodistal corner narrowly rounded. Uropod 1 rami subequal. Uropod 2 rami distinctly unequal, inner ramus with marginal constrictions. Uropod 3 peduncle with dorsolateral flange; rami distinctly unequal, without plumose setae on rami; outer ramus 1–articulate. Telson slightly longer than broad, entire, without dorsal robust setae, with 2 long, apical slender setae.

Habitat. Coral rubble, coarse sand, sand and silt, seagrasses and algae such as Padina and Halimeda in 0 to 32 m depth.

Remarks. Lowry & Stoddart (1994, 1995) discussed morphological differences between populations of P. acuticaudata from northern Papua New Guinea, New Caledonia (type locality) and the Austral Isles in French Polynesia. We can find no differences between the population living on the Great Barrier Reef and the one from the Southwest Lagoon in New Caledonia.

Pseudambasia acuticaudata and Shoemakerella barnardi are the only lysianassid species on the GBR with a constricted inner ramus on uropod 2. Pseudambasia acuticaudata differs from S. barnardi and indeed all GBR species in the combination of a weakly subchelate first gnathopod and an elongate third article on the peduncle of antenna 2.

Distribution. Australia. Queensland: Goodes Island, Torres Strait; Raine Island; Nimrod Passage, Wreck Bay; Ferguson Reef; No. 8 Sand Cay; No. 5 Sandbank Reef; Lizard Island; Myrmidon Reef; Rib Reef; John Brewer Reef; Lodestone Reef; Pandora Reef; Dingo Beach, Bowen; One Tree Island (all current study). Northern Territory: New Year Island; McCluer Island; Oxley Island (current study). New Caledonia. Southwest Lagoon ( Ledoyer 1984). Papua New Guinea. Madang Lagoon ( Lowry & Stoddart 1995). French Polynesia. Austral Isles: Rurutu ( Lowry & Stoddart 1994).

Figures

FIGURE 3. Pseudambasia acuticaudata Ledoyer, 1984, female, 2.5 mm, AM P68938, Raine Island, Great Barrier Reef.

FIGURE 4. Pseudambasia acuticaudata Ledoyer, 1984, female, 2.5 mm, AM P68938, Raine Island, Great Barrier Reef.