Tryphosella martrudan, 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 : 46-49

Tryphosella martrudan sp. nov.

( Figs 30–32 )

Tryphosella sp. 486. — Lowry & Smith, 2003: 56.

Type material. HOLOTYPE, female, ovigerous (2 eggs), 4.0 mm, AM P.69438, mouth of Fortescue Bay , Tasmania, Australia, 43°07.77'S 145°59.47'E, 50 m, baited trap, 9–10 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan, stn TAS-405 . PARATYPES: 1 male, 3.5 mm, AM P.69441 and 5 specimens, AM P.52237, same data as Holotype ; 2 specimens, AM P.52238, same data , stn TAS-406; 2 specimens, AM P.52236, same data , 8–9 April 1994, stn TAS-387; 1 specimen, AM P.52235, same data , 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise, stn TAS-370 .

Additional material examined. Queensland: 1 specimen, AM P.48011, due east of Mooloolaba , 26°39.13'S 153°18.88'E, 51 m, baited trap, 19.9°C, 2–3 August 1994, J.K. Lowry & K. Dempsey, MV Capricorn I, stn QLD- 1123; 1 specimen, AM P.47914, same data, 3–4 August 1994, stn QLD-1142; 1 specimen, AM P.57728, same locality, 50 m, baited trap, 20°C, 2–3 July 1995, J.K. Lowry & K. Dempsey, MV Capricorn I, stn QLD-1195 . New South Wales: female, ovigerous (3 eggs), 4.0 mm, AM P. 69409, 1 male, 3.5 mm, AM P.69410, 1 male, 2.5 mm, AM P.69411, 2 immatures, 2.2 and 2.3 mm, AM P.69412 and P.69413, 1 ovigerous female, 3.5 mm, P.69414, 64 specimens, AM P.52234, due east of Coffs Harbour , New South Wales, Australia, 30°17.49'S 153°13.90'E, 45.4 m, baited trap, 11–12 August 1993, P. Berents, R. T. Springthorpe & W. Vader, MV Cheryl Lee, stn NSW-875; 5 specimens, AM P.48400, off Wollongong, 34°26.42'S 150°58.04'E, 50 m, baited trap, 19.5°C, 7–8 May 1993, P. Freewater, S. Keable & W. Vader, MV Robin E, stn NSW-792; 2 specimens, AM P.48229, same data, stn NSW-793; 1 specimen, AM P.69440, south-west of Montagu Roadstead, Jervis Bay , 35°02.26'S 150°45.06'E, 22 m, baited trap, 11–16 May 1993, C. Alvars; 1 specimen, AM P.69415, north-east of Hyams Beach, Jervis Bay , 35°05.58'S 150°44.32'E, 23 m, baited trap, 11–16 May 1993, C. Alvars; 2 specimens, AM P.69419, north-east of Hyams Beach, Jervis Bay , 35°05.45 'S 150°43.59'E, 22–23 m, baited trap, 11–16 May 1993, C. Alvars; 2 specimens, AM P.69439, north-east of Hyams Beach, Jervis Bay , 35°05.45'S 150°42.00'E, baited trap, 11–16 May 1993, C. Alvars; 1 specimen, AM P.69417, south-west of Longnose Point, Jervis Bay , 35°05.13'S 150°45.37'E, 27 m, baited trap, 11–16 May 1993, C. Alvars; 1 specimen, AM P.69418, north of Bowen Island , Jervis Bay , 35°06.18'S 150°46.17'E, 33 m, baited trap, 11–16 May 1993, C. Alvars, stn 18D; 1 specimen, AM P.69416, east of Bowen Island , Jervis Bay , 35°07.08'S 150°46.37'E, 39 m, baited trap, 11–6 May 1993, C. Alvars, stn 8D; 2 females, AM P.69401 and 2 specimens, AM P.69442, off mouth of Moona Moona Creek , Jervis Bay , NSW, 35°03.5'S 150°41'E, 8 m, air-lifted sediment, P.B. Berents, 29 January 1983, stn NSW-263 .

Type locality. Mouth of Fortescue Bay , Tasmania, Australia, 43°07.77'S 145°59.47'E, 50 m depth .

Etymology. The species is named for handsome cray fishing vessel, MV Martrudan from which the traps were set that caught the type material.

Diagnostic description. Head lateral cephalic lobe rounded, apically rounded; eyes apparently absent. Antenna 1 peduncular article 1 without anterodistal lobe; article 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 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 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 apical robust seta.

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 slightly acute, entire, straight. Gnathopod 2 propodus palm moderately obtuse. 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 or not serrate, without posteroventral lobe or spine. 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 a posteriorlydirected elongate 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 calceoli present. Gnathopod 1 simple; propodus margins tapering distally, palm absent. Uropod 3 with 1 plumose seta on outer ramus.

Remarks. Tryphosella martrudan belongs to a group of four Australian species ( T. betka , T. martrudan , T. toowoomba and T. wangaratta ) in which the male gnathopod 1 is simple. Within this group T. martrudan is most similar to T. betka (see Remarks there-under).

Tryphosella martrudan was uncommon (one catch of 70 specimens but usually less than 10 specimens) in baited traps set in shallow water (20 to 50 m depth) from southern Queensland to Tasmania.

Distribution. Queensland to Tasmania, eastern Australia; 8–51 m depth.

Figures

FIGURE 30. Tryphosella martrudan sp. nov. Female, 3.5 mm, P.69414, east of Coffs Harbour, New South Wales.

FIGURE 31. Tryphosella martrudan sp. nov. Holotype, female, 4.0 mm, AM P.69438; paratype, male, 3.5 mm, AM P.69441; Fortescue Bay, Tasmania. Scale for MX1 represents 0.05 mm, scales for G1, G2 represent 0.2 mm, remainder represent 0.1 mm.

FIGURE 32. Tryphosella martrudan sp. nov. Holotype, female, 4.0 mm, AM P.69438; paratype, male, 3.5 mm, AM P.69441; Fortescue Bay, Tasmania. Scales represent 0.1 mm.