Tryphosella sorell, 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 : 55-59

Tryphosella sorell sp. nov.

( Figs 37–40 )

Tryphosella sp. 135. — Lowry & Smith, 2003: 56.

Type material. HOLOTYPE, female, ovigerous (4 eggs), 5.6 mm, AM P.69380, about 100 m west of Turners Rock and 80 m offshore, north side of Cape Sorell, Tasmania, Australia, 42°11.5'S 145°10.8'E, 13 m, baited trap, probably rocky bottom with sand patches, 27–28 April 1991, RV Flying Scud, J.K. Lowry & S.J. Keable, stn TAS- 301 . PARATYPES: 1 male, 5.5 mm, AM P.69381; 1 male, AM P.69382; 1 female, AM P.69383; 1085 specimens, AM P.69384; same data as Holotype .

Additional material examined. New South Wales: 1 specimen, AM P.48399, off Wollongong , 34°26.42'S 150°58.04'E, 50 m, baited trap, 7–8 May1993, P. Freewater, MV Robin E, stn NSW-792; 6 specimens, AM P.44299, off Wollongong , 34°26.54'S 150°57.98'E, 50 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E, stn NSW-939; 1 specimen, AM P.44315, same data, stn NSW-940 ; 5 specimens, AM P.44331, same data, 28–29 March 1994, stn NSW-958 . Victoria: 85 specimens, AM P.84634, Bay of Islands , 38°35'S 142°49.5'E, 1.5 m, airlift over rubble, 28 April 1988, R. T . Springthorpe , stn VIC-76 . Tasmania: 14 specimens, MV J2682 , 20 km north-north-east of North Point, central Bass Strait , 40°38.0'S 145°23'E, 36 m, muddy shell grit, epibenthic sled, 4 November 1980, M. Gomon & G.C.B. Poore, FRV Sarda , stn BSS 117S; 1 ovigerous female, 6.1 mm, AM P.71615, 1 mature male, 4.8 mm, AM P.71616, 1 immature male, 4.5 mm, AM P.71617 and 296 specimens, AM P.51830, east of Fortescue Bay, north of Hippolyte Rocks , 43°06.70'S 148°03.45'E, 100 m, baited trap, 15.8°C, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise , stn TAS-371 ; 163 specimens, AM P.51831, same data, stn TAS-372 ; 1 specimen, AM P.51832, mouth of Fortescue Bay , 43°07.77'S 145°59.47'E, 50 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan , stn TAS-386 ; 1 specimen, AM P. 58249, east of Fortescue Bay, north of Hippolyte Rocks , 43°06.70'S 148°03.45'E, 100 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan , stn TAS-389 . South Australia: many specimens, SAM C6950 and 21 specimens, AM P.85257, Marion Bay, Yorke Peninsula , approx. 35º14'S 136º59'E, 3 m, on dead crayfish in pot, 3 January 1977, W. Zeidler; many specimens, SAM C6951 , Marion Bay, Yorke Peninsula , approx. 35°14’S 137°00’E, 6–10 m, bait in craypot, 29 January 1979, W. Zeidler ; 35 specimens, SAM C6952 , Marion Bay, Yorke Peninsula , approx. 35º14'S 136º59'E, 15 m, on bait in cray pot, 28 January 1980, W. Zeidler .

Type locality. About 100 m west of Turners Rock and 80 m offshore, north side of Cape Sorell , Tasmania, Australia, 42°11.5'S 145°10.8'E, 13 m depth .

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 produced equally with 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 1.3 x breadth), subtriangular, tapering distally; basis moderately setose along anterior margin; ischium short; carpus long, subequal in length to propodus, without posterior lobe; propodus small, margins subparallel, sparsely setose along posterior margin, palm transverse. 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, 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 subquadrate. Urosomite 1 not projecting over urosomite 2, with anterodorsal notch and rounded boss. Uropods 1 and 2 outer rami with all robust setae stout and striated. Uropod 2 inner ramus without constriction. Uropod 3 peduncle without dorsolateral flange, with 1 short apicomedial robust seta; 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 subtriangular. Antenna 1 calceoli present, proximal calceolus very large. Antenna 2 peduncular articles 4 and 5 enlarged; flagellum long, calceoli present. Epistome/Upper lip epistome produced beyond upper lip, narrowly rounded. Uropod 3 with plumose setae on both rami.

Remarks. Tryphosella sorell is one of the group of six Australian species with stout striated robust setae on the outer rami of uropods 1 and 2 (see Remarks under T. fortescue ). Only two species, T. freycinet and T. sorell , have all of the robust setae in this form. See Remarks under T. freycinet .

Tryphosella sorell appears to be a widespread shallow-water scavenger in New South Wales, Victoria, Tasmania and South Australia from the subtidal down to 100 m depth (up to about 1085 specimens in a trap).

Distribution. South-eastern and southern Australia, 1.5–100 m depth.

Figures

FIGURE 37. Tryphosella sorell sp. nov. Paratype, female, 6.1 mm, AM P.71615, east of Fortescue Bay, Tasmania.

FIGURE 38. Tryphosella sorell sp. nov. Holotype, female, 5.6 mm, AM P.69380; paratype, male, 5.5 mm, AM P.69381, Cape Sorell, Tasmania. Scales represent 0.2 mm.

FIGURE 39. Tryphosella sorell sp. nov. Holotype, female, 5.6 mm, AM P.69380, Cape Sorell, Tasmania. Scales represent 0.2 mm.

FIGURE 40. Tryphosella sorell sp. nov. Holotype, female, 5.6 mm, AM P.69380; paratype, male, 5.5 mm, AM P.69381, Cape Sorell, Tasmania. Scales represent 0.1 mm.