Tryphosella cooee, Lowry & Stoddart, 2011

Lowry, J. K. & Stoddart, H. E., 2011, The tryphosine genera Photosella gen. nov. and Tryphosella Bonnier, 1893 (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae) in Australian waters 2956, Zootaxa 2956 (1), pp. 1-76 : 34-38

Tryphosella cooee sp. nov.

( Figs 20–23 )

Tryphosella sp. 146. — Lowry & Smith, 2003: 56.

Type material. HOLOTYPE, female, ovigerous, 10.0 mm, AM P.69623, east of Fortescue Bay , Tasmania, Australia, 43°08.96'S 145°15.36'E, 1000 m, baited trap, 4.9°C, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan, stn TAS-403 . PARATYPES: 1 male, 8.5 mm, AM P.69624 and 12 specimens, AM P.51973, same data as Holotype ; 10 specimens, AM P.51845, east of Fortescue Bay , Tasmania, 43°08.96'S 145°15.36'E, 1000 m, baited trap, 5.1°C, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise, stn TAS-365 ; 23 specimens, AM P.51846, same data , stn TAS-367; 21 specimens, AM P.51847, east of Fortescue Bay , Tasmania, Australia, 43°08.96'S 145°15.36'E, 1000 m, baited trap, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise, 17–18 April 1993, stn TAS-383 ; 8 specimens, AM P.51848, same data , stn TAS-384; 2 specimens, AM P.51980, east of Fortescue Bay , Tasmania, Australia, 43°08.96'S 145°15.36'E, 1000 m, baited trap 1, 9–10 April 1994, J.K. Lowry & K. Dempsey on MV Martrudan, stn NSW-419 ; 1 specimen, AM P.51981, same data , stn TAS-421; 6 specimens, AM P.51982, east of Fortescue Bay , Tasmania, Australia, 43°08.96'S 145°15.36'E, 1000 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan, stn TAS-422 ; 15 specimens, AM P.57979, same data , stn TAS-423.

Additional material examined. Tasmania: 5 specimens, AM P.51849, east of Fortescue Bay, 43°07.36'S 145°13.75'E, 400 m, baited trap, 10.0° C, J.K. Lowry & K. Dempsey, MV Martrudan , 8–9 April 1994, stn TAS- 398 ; 8 specimens, AM P.51971, same data, stn TAS-399 ; 13 specimens, AM P.51972, same data, stn TAS-400 ; 11 specimens, AM P.51974, same data, 9–10 April 1994, stn TAS-417 ; 22 specimens, AM P.51979, same data, stn

TAS-418; 22 specimens, AM P.76853 to AM P.76857, north of Hill U Seamount, Huon Study Area, 44°17'32"S 147°11'36"E, 1350 m, baited trap, 7 April 2007, S.J. Keable , RV Southern Surveyor , stn SS02/2007/57 .

Type locality. East of Fortescue Bay , Tasmania, Australia, 43°08.96'S 145°15.36'E, 1000 m depth .

Etymology. Named for the north-coast town of Cooee, Tasmania.

Diagnostic description. Head lateral cephalic lobe a semidome, apically subacute; eyes apparently absent. Antenna 1 peduncular articles 1 and 2 without anterodistal lobe; accessory flagellum not forming cap, terminal article not offset; flagellum with strong 2-field callynophore, robust setae present on proximal articles; calceoli absent. Antenna 2 peduncular article 3 short; articles 4 and 5 not enlarged; flagellum short, calceoli absent. Epistome/ Upper lip separate; epistome produced beyond upper lip, acute; upper lip slightly produced, straight. Mandible molar with asymmetrically reduced column, proximally setose, distally triturating; palp attached about midway, article 3 with proximal A3-seta. Maxilla 1 outer plate setal-tooth 7 left and right symmetrical, left and right cuspidate along most of slightly sinusoidal inner margin; palp distal margin with apical robust setae. Maxilliped basis without recurved hook; outer plate with 2 long apical robust setae.

Gnathopod 1 subchelate; coxa medium length (length 1.5 x breadth), subtriangular, tapering distally; basis densely setose along anterior margin; ischium short; carpus long, longer than propodus, without posterior lobe; propodus small, margins subparallel, sparsely setose along posterior margin, palm slightly acute, entire, straight. Gnathopod 2 palm transverse. Pereopod 4 coxa without distinct lateral ridge, with a well-developed posteroventral lobe. Pereopod 5 coxa without distinct lateral ridge, without umbo; basis about as long as broad, without photophore, not posteroproximally excavate, posterior margin not serrate. Pereopod 7 basis posterodistally produced less than halfway along merus, not posterodistally excavate.

Pleonites 1–3 without mid-dorsal carina, not produced dorsodistally. Epimeron 3 posterior margin smooth, posteroventral corner subacutely produced. Urosomite 1 posterodorsally straight. Uropods 1 and 2 outer rami without stout striated robust setae. Uropod 2 inner ramus without constriction. Uropod 3 peduncle without dorsolateral flange, with 2 short apicomedial robust setae; inner and outer rami well developed, outer ramus article 2 short, with 1 plumose seta on outer ramus. Telson deeply cleft, with dorsal robust setae, with 1 apical robust seta on each lobe.

Male (sexually dimorphic characters). Antenna 1 calceoli present, small. Antenna 2 flagellum long, calceoli present. Epistome/Upper lip epistome produced equally with upper lip, narrowly rounded. Epimeron 3 posteroventral corner narrowly rounded. Urosomite 1 with wedge-shaped boss, obliquely truncated apically. Uropod 3 with plumose setae on both rami.

Remarks. Within the Australasian area T. cooee and T. chinchilla are the only species which have the combined characters of gnathopod 1 with a medium-sized coxa and a densely setose anterior margin on the basis. See under T. chinchilla for further Remarks.

Tryphosella cooee was uncommon (1 to 23 specimens per trap) in baited traps from 400 and 1000 m depth off Tasmania .

Distribution. Victoria and Tasmania, southern Australia; 400–1840 m depth.

Figures

FIGURE 20. Tryphosella cooee sp. nov. Holotype, female, 10.0 mm, AM P.69623, east of Fortescue Bay, Tasmania.

FIGURE 21. Tryphosella cooee sp. nov. Holotype, female, 10.0 mm, AM P.69623; paratype, male, 8.5 mm, AM P.69624; east of Fortescue Bay, Tasmania. Scales represent 0.2 mm.

FIGURE 22. Tryphosella cooee sp. nov. Holotype, female, 10.0 mm, AM P.69623, east of Fortescue Bay, Tasmania. Scales represent 0.2 mm.

FIGURE 23. Tryphosella cooee sp. nov. Holotype, female, 10.0 mm, AM P.69623; paratype, male, 8.5 mm, AM P.69624; east of Fortescue Bay, Tasmania. Scales represent 0.2 mm.