Tryphosella fortescue, Lowry & Stoddart, 2011

Tryphosella fortescue View in CoL sp. nov.

( Figs 24–26 View FIGURE 24 View FIGURE 25 View FIGURE 26 )

Tryphosella sp. 183. — Lowry & Smith, 2003: 56.

Type material. HOLOTYPE, female, ovigerous ( 6 eggs), 5.4 mm, AM P. 71619, east of Fortescue Bay , north of Hippolyte Rocks, Tasmania, Australia, 43°06.70'S 148°03.45'E, 100 m, baited trap, 9–10 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan, stn TAS-408 GoogleMaps . PARATYPES: 1 male, 5.0 mm, AM P.71620; 1 male, 4.4 mm, AM P.71621; 296 specimens, AM P.52145; all with same data as Holotype GoogleMaps .

Additional material examined. New South Wales: 10 specimens, AM P.69596, north of Toomeree Head, Port Stephens , 32°42.7'S 152°11.2'E, 15 m, close to rocky shore, baited trap set 1000 –1100 hrs, retrieved 0730–0830 hrs, 1– 2 June 1988, J.K. Lowry & S.J. Keable, stn NSW-304 GoogleMaps ; 28 specimens, AM P.47030, off Wollongong, 34°32.09'S 151°12.55'E, 200 m, baited trap, 13.7°C, 7–8 May 1993, P. Freewater, S. Keable & W. Vader, MV Robin E, stn NSW-797 GoogleMaps ; 1 specimen, AM P.47014, same data, stn NSW-798 GoogleMaps . Tasmania: 1 specimen, MV J11280 View Materials , 25 km northeast of Deal Island, eastern Bass Strait , 39°14.8'S 147°31.5'E, 57 m, medium sand, Smith-McIntyre grab, 18 November 1981, RV Tangaroa , stn BSS 174G GoogleMaps ; 7 specimens, MV J 62309 View Materials , 100 km south-south-east of Cape Liptrap, central Bass Strait, 39°45.9'S 145°33.5'E, 74 m, muddy fine sand, epibenthic sled, 13 November 1981, R. Wilson, RV Tangaroa , stn BSS-156S; many specimens, AM P.69594, about 100 m west of Turners Rock and 80 m offshore, north side of Cape Sorell , 42°11.5'S 145°10.8'E, 13 m, baited trap, probably rocky bottom with sand patches, 27– 28 April 1991, J.K. Lowry & S.J. Keable, stn TAS-301 GoogleMaps ; 7 specimens, AM P.69595, 50 m off Weatherhead, Freycinet Peninsula , 42°14'S 148°15'E, 13 m, baited trap, 30 April–1 May 1991, J.K. Lowry & S.J. Keable, stn TAS-339 GoogleMaps ; 1 specimen, AM P.45746, mouth of Fortescue Bay, 43°07.77'S 145°59.47'E, 50 m, baited trap, 16.2°C, 16-17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise , stn TAS-350 GoogleMaps ; 2 specimens, AM P.52088, same data, 17–18 April 1993, stn TAS-370 GoogleMaps ; 3 specimens, AM P.52090, same locality, 16.6°C, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan , stn TAS-386 GoogleMaps ; 1 specimen, AM P.52091, same data,, stn TAS-387 GoogleMaps ; 40 specimens, AM P.52095, same data, 9–10 April 1994, stn TAS-405 GoogleMaps ; 1 specimen, AM P.52096, same data, stn TAS-406 GoogleMaps ; 24 specimens, AM P.52087 and 3 specimens, AM P.57741, east of Fortescue Bay, north of Hippolyte Rocks, 43°06.70'S 148°03.45'E, 100 m, baited trap, 15.8°C, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise , stn TAS-354 GoogleMaps ; 2 specimens, AM P.52089, same data, 17–18 April 1993, stn TAS-372 GoogleMaps ; 23 specimens, AM P.52092, same locality,15.6°C, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan , stn TAS-389 GoogleMaps ; 24 specimens, AM P.52093 and 1 specimen, AM P.71618, same data, stn TAS-390 ; 110 specimens, AM P.52094, same data, stn TAS-391 ; 6 specimens, AM P.52146, same data, 9–10 April 1994, stn TAS-409 ; 1 specimen, AM P.52147, same data, 200 m, stn TAS-410 . South Australia: 11 specimens, SAM C6948 View Materials , Wedge Island , 35°11.00’S 136°29.85’E, 10 m, baited trap set overnight, 22 March 2001, V. Martin, Waterhouse Club Expedition GoogleMaps ; 3 specimens, SAM C6947 View Materials , Dangerous Reef, Spencer Gulf , approx. 34°49’S 136°12’E, dredged, K. Sheard GoogleMaps ; 6 females, 1 immature male, SAM C6949 View Materials , North Cove, Pearson Island , 33°56.30’S 134°15.9’E, 25 m, baited trap set overnight, 17–18 March 2001, V. Martin, Waterhouse Club Expedition GoogleMaps .

Type locality. East of Fortescue Bay , north of Hippolyte Rocks, Tasmania, Australia, 43°06.70'S 148°03.45'E, 100 m depth GoogleMaps .

Etymology. The species is named for its type locality.

Diagnostic description. Head lateral cephalic lobe rounded, apically rounded; 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 absent from 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 slightly produced beyond upper lip, broadly rounded; 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 asymmetrical, left cuspidate along most of sinusoidal inner margin, right cuspidate along most of curved inner margin; palp distal margin with apical robust setae. Maxilliped basis without recurved hook; outer plate with 1 short apicolateral robust seta and 3 short apical robust setae.

Gnathopod 1 subchelate; coxa small (length 1.1 x breadth), subtriangular, tapering distally; 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 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 not projecting over urosomite 2, with deep notch and subtriangular, subacute boss. Uropods 1 and 2 outer rami with distal 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, without plumose setae on rami. Telson deeply cleft, with dorsal robust setae, with 2 apical robust setae on each lobe.

Male (sexually dimorphic characters). Head lateral cephalic lobe a semidome, apically subacute. Antenna 1 calceoli present, proximal calceolus very large. Antenna 2 flagellum long, calceoli present, proximal calceolus very large. Epimeron 3 posteroventral corner narrowly rounded. Urosomite 1 with wedge-shaped boss, obliquely truncated apically. Uropod 3 with plumose setae on both rami.

Remarks. Tryphosella fortescue belongs to a group of Australian species ( T. fortescue , T. freycinet , T. orana , T. sorell , T. tathra and T. tuckanarra ) in which some or all of the robust setae on the outer ramus of uropods 1 and/ or 2 are stouter than the others and have longitudinal striations. This group also share the characters of: no robust setae on antenna 1 flagellum, no long apical robust setae on the maxilliped outer plate, gnathopod 1 basis with a weakly setose anterior margin and a short ischium, urosomite 1 with some form of irregular or triangular boss and no plumose setae on uropod 3 of the females. They vary in: the shape of the lateral cephalic lobe, the number of apical robust setae on the maxilliped outer plate, the size of coxa 1, the angle of the gnathopod 2 palm, the shape of the boss on urosomite 1, the number of stout striated setae on uropods 1 and 2, the number of short apicomedial robust setae on the peduncle of uropod 3 and the number of apical robust setae on each lobe of the telson. It is interesting that all six species occur in southern Australia; none of the species from Queensland or nearby Papua New Guinea and New Caledonia have these unusual robust setae.

Of these six species all but T. tuckanarra have a significantly shortened subtriangular coxa 1 (about as long as broad). Only T. fortescue and T. sorell have a transverse palm on gnathopod 2. Tryphosella fortescue differs from T. sorell in having a subtriangular, subacute boss on urosomite 1 (rounded in T. sorell ) and 2 short apicomedial robust setae on uropod 3 peduncle ( 1 in T. sorell ).

Although T. fortescue occurred off the coast of New South Wales and South Australia it was captured most frequently off eastern Tasmania down to 200 m depth (up to 300 specimens in a trap).

Distribution. New South Wales, Tasmania and South Australia, eastern and southern Australia; 10–200 m depth.