Tryphosella bicheno, 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 : 21-23

Tryphosella bicheno sp. nov.

( Figs 10–12 )

Tryphosella sp. 168/182. — Lowry & Smith, 2003: 56.

Type material. HOLOTYPE, female, 7.0 mm, P.70514, east of Fortescue Bay , Tasmania, Australia, 43°8.96'S 145°15.36'E, 1000 m, baited trap, 5.1°C, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise, stn TAS-384 . PARATYPES: 1 female, 7.2 mm, AM P.70513; 1 male, 7.5 mm, AM P.70515; 1 male, 6.4 mm, AM P.70516; 1 female, 4.6 mm, AM P.70517; 1 male, 4.6 mm, AM P.70518; 1?female, 4.2 mm, AM P.70519; 1?male, 4.1 mm, AM P.70520; 1 female, 7.8 mm, AM P.70521; 2242 specimens, P.51935; all with same data as Holotype. 1611 specimens, P.51934, same data, stn TAS-383 ; 21 specimens, P.51928, same data, 16–17 April 1993, stn TAS- 365 ; 69 specimens, P.51929, same data, stn TAS-367 .

Additional material examined. Queensland: 5 specimens, P.58073, east of Flynn Reef , 16°41.61’S 146°17.94’E, 100 m, baited trap, 6–7 June 1993, J.K. Lowry, P. Freewater & W. Vader, RV Sunbird , stn QLD-918 ; 8 specimens, P.58071, same data, stn QLD-936 ; 971 specimens, P.57744, same locality, 50 m, baited trap, 18–19 May, 1994 J.K. Lowry & K. Dempsey, RV Sunbird , stn QLD-1033 . New South Wales: 1 specimen, P.44409, off Wollongong , 34°32.53'S 151°17.07'E, 400 m, baited trap, 6–7 May 1993, P. Freewater, S. Keable & W. Vader, MV Robin E, stn NSW-787; 4 specimens, P.44435 and 1 specimen, P.44446, off Wollongong , 34°32.39'S 151°15.00'E, 300 m, baited trap, 7–8 May 1993, P. Freewater, S. Keable & W. Vader, MV Robin E, stn NSW-802; 2 specimens, P.44420, off Wollongong , 34°33.01'S 151°16.54'E, 400 m, baited trap, 7–8 May 1993, P. Freewater, S. Keable & W. Vader, MV Robin E, stn NSW-804. Tasmania: 4 specimens, MV J62304 , off Freycinet Peninsula , 41°58.60'S 148°38.80'E, 500 m, coarse shell, WHOI epibenthic sled, M.F. Gomon et al., 27 July 1986, RV Franklin , stn SLOPE 47 ; 4 specimens, P.51936, mouth of Fortescue Bay , 43°07.77'S 145°59.47'E, 50 m, baited trap, 16.6°C, 8– 9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan , stn TAS-387 ; 33 specimens, P.57706, east of Fortescue Bay, north of Hippolyte Rocks , 43°6.70'S 148°03.45'E, 100 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise , stn TAS-372 ; 2 specimens, P.52239 and 12 specimens, P.58241, same locality, 100 m, baited trap, 8–9 April 1994, 15.6°C, J.K. Lowry & K. Dempsey on MV Martrudan , stn TAS-389 ; 3 specimens, P.57704, east of Fortescue Bay , 43°06.70'S 145°13.6'E, 200 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, 16–17 April 1993, MV Tasmanian Enterprise , stn TAS-356 ; 2 specimens, P.57705, same data, stn TAS-357 ; 1 specimen, P.57707, same data, 17–18 April 1993, stn TAS-376 ; 7 specimens, P.51937 and 17 specimens, P.57711, same locality, 200 m, baited trap, 13.2° C, J.K. Lowry & K. Dempsey, MV Martrudan , 8–9 April 1994, stn TAS-392 ; 1 specimen, P.51938, same data, stn TAS-393 ; 30 specimens, P.51226, same data, stn TAS-394 ; 1 specimen, P.51944, same data, 9–10 April 1994, stn TAS-412 ; 64 specimens, P.51925, east of Fortescue Bay , 43°09.37'S 145°13.6'E, 300 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, 16–17 April 1993, MV Tasmanian Enterprise , stn TAS-359 ; 30 specimens, P.51926, same data, stn TAS-361 ; 11 specimens, P.51930, same data, 17–18 April 1993, stn TAS-377 ; 3 specimens, P.51931, same data, stn TAS-378; 1414 specimens, P.51939, same locality, 300 m, baited trap, 11.0° C, J.K. Lowry & K. Dempsey, MV Martrudan , 8–9 April 1994, stn TAS-395 ; 758 specimens, P.51235, same data, stn TAS-396 ; 459 specimens, P.51940, same data, stn TAS-397 ; 274 specimens, P.51945, same data, 9–10 April 1994, stn TAS-414 ; 247 specimens, P.51946, same data, stn TAS-415; 1269 specimens, P.51022, east of Fortescue Bay , 43°07.36'S 145°13.75'E, 400 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, 16–17 April 1993, MV Tasmanian Enterprise , stn TAS-362; 1707 specimens, P.51927, same data, stn TAS-364; 1003 specimens, P.51932, same data, 17–18 April 1993, stn TAS-380 ; 234 specimens, P.51933, same data, stn TAS-382 ; 537 specimens, P.51941, same locality, 400 m, baited trap, 10.0° C, J.K. Lowry & K. Dempsey, MV Martrudan , 8–9 April 1994, stn TAS-398 ; 885 specimens, P.51942, same data, stn TAS-399; 1457 specimens, P.51943, same data, stn TAS-400; 1337 specimens, P.51947, same data, 9–10 April 1994, stn TAS-417; 1531 specimens, P.51948 and 1 specimen, P.71633, same data, stn TAS-418 .

Type locality. East of Fortescue Bay , Tasmania, Australia, 43°08.96'S 14515.36'E, 1000 m depth .

Etymology. The species is named for the town of Bicheno on the east coast of Tasmania.

Diagnostic description. Head lateral cephalic lobe a semidome, apically rounded; eyes lageniform but fading completely in alcohol. 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, 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 slightly 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 long apicolateral seta and 3 long apical robust setae.

Gnathopod 1 subchelate; coxa small (length 1.3 x breadth), subtriangular, tapering distally; basis moderately setose along anterior margin; ischium long; carpus long, longer than propodus, without posterior lobe; propodus small, margins subparallel, sparsely setose along posterior margin, palm moderately 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 weakly 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 acutely produced. Urosomite 1 not projecting over urosomite 2, with anterodorsal notch and rounded boss. 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, without plumose setae on rami. Telson deeply cleft, with dorsal robust setae, with 1 apical robust seta on each lobe.

Male (sexually dimorphic characters). Head lateral cephalic lobe subtriangular. Antenna 1 calceoli present, small. Antenna 2 flagellum long, calceoli present. Uropod 3 with plumose setae on both rami.

Remarks. Tryphosella bicheno appears to be most similar to T. astrolabensis and T. wongada (both from northern Papua New Guinea). They all have a long ischium on gnathopod 1, robust setae on the proximal articles of antenna 1 flagellum, an acutely produced posteroventral corner on epimeron 3 and a rounded boss on urosomite 1. Tryphosella bicheno differs from T. astrolabensis and T. wongada in having 1 long apicolateral and 3 long apical setae on the maxilliped outer plate, a transverse palm on gnathopod 2 and only 1 apical robust seta on each lobe of the telson.

Tryphosella bicheno is a scavenger along the east coast of Australia. It occurred in 50 to 100 m depth off the Great Barrier Reef (up to 970 specimens in a trap) and in small numbers off the New South Wales central coast in 300 to 400 m depth (up to 5 specimens in a trap). Off the Tasmanian coast it occurred in small numbers from 50 to 200 m depth (up to 65 specimens in a trap), but most frequently and in the highest numbers in depths from 300 to 1000 m (up to 2250 specimens in a trap) .

Distribution. Queensland to Tasmania, eastern Australia; 50–1000 m depth.

Figures

FIGURE 10. Tryphosella bicheno sp. nov. Paratype, female, 7.2 mm, P.70513, east of Fortescue Bay, Tasmania.

FIGURE 11. Tryphosella bicheno sp. nov. Holotype, female, 7.0 mm, P.70514; paratype, male, 7.5 mm, AM P.70515; east of Fortescue Bay, Tasmania. Scales for G1, G2 represent 0.5 mm, remainder represent 0.2 mm.

FIGURE 12. Tryphosella bicheno sp. nov. Holotype, female, 7.0 mm, P.70514; paratype male, 7.5 mm, AM P.70515; east of Fortescue Bay, Tasmania. Scales represent 0.2 mm.