Tryphosites psittacus sp. nov.

(Figs 42–45)

Types. Holotype female, 7.5 mm, AM P.69287, east of Broken Bay, New South Wales, Australia (33°31' S, 152°08’E), 914 m, 2.5 m sled dredge, 10 December 1980, R. T. Springthorpe, FRV Kapala stn K80-20-08 . Paratypes: male, 6.7 mm, AM P.69288; 2 specimens, 6.4–7.6 mm, AM P.69289; 1 specimen, 6.8 mm, AM P.69291, all same collection data as holotype; 1 specimen, 7.0 mm, AM P.69290, east of Broken Bay, New South Wales, Australia (33°37' S, 152°04’E), 896–923 m, dredged, 10 December 1980, R . T. Springthorpe, FRV Kapala stn K80- 20-09 .

Additional material examined. New South Wales: 2 specimens, NMV J67518, 54 km ESE of Nowra, New South Wales, Australia (34°52.72'S 151°15.04'E), 996 m, mud, fine sand, fine shell, WHOI epibenthic sled, 22 October 1988, G.C.B. Poore et al., RV Franklin, SLOPE stn 53. Tasmania: 79 specimens, NMV J67519, off Freycinet Peninsula, Tasmania, Australia (42°0.20'S 148°37.70'E), 720 m, coarse shelly sand, WHOI epibenthic sled, 27 July 1986, M.F. Gomon et al., RV Franklin SLOPE stn 46. 2 specimens, NMV J67520, off Freycinet Peninsula, Tasmania, Australia (41°58.60'S 148°38.80'E), 500 m, coarse shell, WHOI epibenthic sled, 27 July 1986, M.F. Gomon et al., RV Franklin, SLOPE stn 47. 3 specimens, NMV J67521, off Freycinet Peninsula, Tasmania, Australia (42°2.20 'S 148°38.70'E), 800 m, coarse shelly sand, WHOI epibenthic sled, 27 July 1986, M.F. Gomon et al., RV Franklin, SLOPE stn 45. 3 specimens, NMV J67524, 48 km ENE of Cape Tourville, Tasmania, Australia (42°00.25'S 148°43.55'E), 1264 m, gravel with lumps of sandy mud aggregate, WHOI epibenthic sled, 30 October 1988, G.C.B. Poore et al., RV Franklin, SLOPE stn 81. 1 specimen, NMV J14618, off Freycinet Peninsula, Tasmania, Australia (41°57.50'S 148°37.90'E), 400 m, coarse shell, WHOI epibenthic sled, 27 July 1986, M.F. Gomon et al., RV Franklin, SLOPE stn 48 .

Victoria: 157 specimens, NMV J67522, south of Point Hicks, Victoria, Australia (38°17.70'S 149°11.30'E), 400 m, coarse sand, gravel, mud, many sponges, WHOI epibenthic sled, 24 July 1986, M.F. Gomon et al., RV Franklin, SLOPE stn 40. 12 specimens, NMV J67523, south of Point Hicks, Victoria, Australia (38°19.60'S 149°24.30'E), 930 m, rock, rubble, clay, sand, biogenic sed., WHOI epibenthic sled, 23 July 1986, M.F. Gomon et al., RV Franklin, SLOPE stn 33 .

Type locality. East of Broken Bay, New South Wales, Australia (33°31' S, 152°08’E), 914 m depth .

Etymology. Named psittacus (Latin), meaning parrot, referring to the epistome and upper lip complex which resembles a parrot’s beak.

Description. Based on holotype, female, 7.5 mm, AM P.69287. Head lateral cephalic lobe semidome, apically subacute. Antenna 1 peduncular article 1 without anterodistal lobe; article 2 without anterodistal lobe; accessory flagellum present, not forming operculum, terminal article not offset; flagellum with weak 2-field callynophore, robust setae absent from proximal articles; calceoli absent. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged; flagellum short, calceoli absent. L abrum epistome/upper lip separate; epistome slightly produced beyond upper lip, narrowly rounded; upper lip not produced. Mandible molar columnar, with oval fully triturating surface; palp attached midway. Maxilla 1 outer plate setal-tooth 7 present, left and right symmetrical, cuspidate distally; palp distal margin with apical robust setae. Maxilliped outer plate with 2 short, broad apical robust setae.

Pereonites 1–7 dorsally smooth. Gnathopod 1 subchelate; coxa large, about as long as coxa 2, distally subovate; basis moderately setose along anterior margin; ischium short; carpus long, longer than propodus, without posterior lobe; propodus small, margins subparallel, sparsely setose along posterior margin, palm moderately acute, entire, straight. Gnathopod 2 minutely chelate propodus palm moderately obtuse. Pereopod 5 basis longer than broad, not posteroproximally excavate, posterior margin not serrate. Pereopod 7 basis posterodistally produced less than halfway along merus.

Pleonites 1–3 without mid-dorsal carina, not produced dorsodistally. Epimeron 3 posterior margin smooth, posteroventral corner broadly rounded. Urosomite 1 dorsally straight. Uropod 2 inner ramus with constriction. Uropod 3 peduncle without dorsolateral flange; inner and outer rami well developed, outer ramus article 2 short, without plumose setae on rami. Telson moderately cleft, longer than wide, with 3 dorsal robust setae per lobe and 1 apical robust seta on each lobe.

Sexually dimorphic characters. Based on paratype male AM P.69288. Antenna 1 flagellum article 1 with strong 2-field callynophore; calceoli present, small. Antenna 2 peduncular article 3 short; articles 4 and 5 slightly broader than female; flagellum long, calceoli present. Uropod 3 with plumose setae on both rami.

Remarks. Tryphosites psittacus sp. nov. differs from all other Tryphosites species by lacking the acutely produced epistome. Instead this species has an unusual epistome and upper lip complex in which the epistome is slightly produced in front of the upper lip and both are apically rounded.

Depth range. 400–1264 m.

Distribution. Australia. Continental slope from Broken Bay, New South Wales, to the Freycinet Peninsula, Tasmania.