Stephonyx pirloti ( Sheard, 1938 )

Lowry, J. K. & Kilgallen, N. M., 2014, A generic review of the lysianassoid family Uristidae and descriptions of new taxa from Australian waters (Crustacea, Amphipoda, Uristidae), Zootaxa 3867 (1), pp. 1-92 : 68-74

Stephonyx pirloti ( Sheard, 1938)

( Figs 42–44 )

Euonyx normani .— Chilton, 1921: 52, figs 5a–d.— Pirlot, 1933: 120 (key).— Sheard, 1937: 19.

Euonyx pirloti Sheard, 1938: 170 , figs 1–3.—J.L. Barnard, 1958: 92.— Zeidler, 1986: 109.— Barnard & Ingram, 1990: 3 (key).— Barnard & Karaman, 1991: 485.

Euonyx pirloti .— Springthorpe & Lowry, 1994: 28.

Stephonyx pirloti .— Lowry & Stoddart, 1989: 521.— Lowry & Stoddart, 2003: 284.— Diffenthal & Horton, 2007: 39 (key).— Senna & Serejo, 2007: 13 (key).— Narahara et al., 2012: 1505 (key).

Types. Syntypes, five specimens (one dissected), SAMA C2177 ; one microscope slide (lost) SAMA C2201 .

Type locality. Nepean Bay, Kangaroo Island , South Australia (~ 35°42'S 137°45'E) .

Additional material examined. New South Wales. 1 specimen, AM P.57649, north-east of Coffs Harbour (30°14.63’S 153°24.68’E), 199 m, baited trap, 12–13 August 1993, P.B. Berents, R. T . Springthorpe & W. Vader, MV Cheryl Lee [NSW-882]; 5 specimens, AM P.63983; 320 specimens, AM P.44268; 1 specimen, AM P.63984, off Wollongong (34°31.48’S 151°13.22’E), 200 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-946]; 628 specimens, AM P.44258, off Wollongong (34°31.48’S 151°13.22’E), 200 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-944]; 87 specimens, AM P.43486, off Wollongong (34°31.48’S 151°13.22’E), 200 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-945]; 446 specimens, AM P.44245; 446 specimens, AM P.44307, off Wollongong (34°31.48’S 151°13.22’E), 200 m, Globigerina ooze, baited trap, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-964]; 439 specimens, AM P.46909, off Wollongong (34°32.02’S 151°13.0’E), 200 m, baited trap, 6–7 May 1993, P. Freewater & party, MV Robin E [NSW-781]; 2 specimens, AM P.44417, off Wollongong (34°33.02’S 151°16.53’E), 400 m, Globigerina ooze, baited trap, 7–8 May 1993, P. Freewater & party, MV Robin E [NSW-803]; 1 female, AM P.96595; 1 male, AM P.96594, 1832 specimens, AM P.44231, off Wollongong (34°31.48’S 151°13.22’E), 200 m, Globigerina ooze, baited trap, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-962]; 1 specimen, AM P.44429, off Wollongong (34°32.38’S 151°15.0’E), 300 m, Globigerina ooze, baited trap, 7–8 May 1993, P. Freewater & party, MV Robin E [NSW-801]; 377 specimens, AM P.46928, off Wollongong (34°32.02’S 151°13.0’E), 200 m, baited trap, 6–7 May 1993, P. Freewater & party, MV Robin E [NSW-780]; 437 specimens, AM P.47037, off Wollongong (34°32.08’S 151°12.55’E), 200 m, baited trap, 7–8 May 1993, P. Freewater & party, MV Robin E [NSW-797]; 1 specimen, AM P.51131, north-east of Coffs Harbour (30°10.88’S 153°32.22’E), 1000 m, baited trap, 12–13 August 1993, P.B. Berents, R . T . Springthorpe & W. Vader, MV Cheryl Lee [NSW-877] ; 1 specimen, AM P.85714, south-east of Port Stephens (32°52’S 152°32’E), 145 m, dredge, 6 December 1978, FRV Kapala [K78-26-07]; 367 specimens, AM P.47023, off Wollongong (34°32.08’S 151°12.55’E), 200 m, baited trap, 7–8 May 1993, P. Freewater & party, MV Robin E [NSW-798]; 1 specimen, AM P.85715, east of The Entrance (33°22’S 152°04’E), 205 m, benthic trawl, 11 February 1986, FRV Kapala [K86-01- 04]; 59 specimens, AM P.43513, off Wollongong (34°31.48’S 151°13.22’E), 200 m, baited trap, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-963]; 1 specimen, AM P.24235, east of Long Reef (33º44’S 151º22’E) 32 m, 1973, Australian Museum Shelf Benthic Survey .

South Australia. 1 specimen, AM P.68511, Kangaroo Island, Penneshaw, 8 km off Hogg Point , (35°37’S 137°57’E), 25 m, trawl, 30 May 2001, W. Rumball, MRV Ngérin ; 1 specimen, AM P.85719, Gulf St Vincent , 8–10 km off Semaphore (34°52'S 138°20'E), 9 m, 1925–1925, H.M. Hale [ SA 74 ]; 1 specimen, AM P.85718, Investigator Strait (35°33'S 137°37'E), 50–80 m, J.C. Verco; 5 specimens, AM P.85709, Yorke Peninsula, Edithburgh Pier (35°05'S 137°45'E), 3 m, baited trap, 16 April 2008, T. Laperousaz; 2 specimens, AM P.85713, Gulf St Vincent, Marino (35°03'S 138°31'E), 1910, W.H. Baker [ SA 79 ]; 2 specimens, SAMA C8034 , Dangerous Reef, Spencer Gulf, South Australia, [approx. 34°49’S 136°12’E], dredged, K. Sheard; 1 specimen, SAMA C8035 , 8 miles off Halletts Cove, Gulf St Vincent, South Australia [approx. 35°05’S 138°30’E], 30 m, A. T. trawl, 2-2.30 a.m., 14 April 1945, H.M. Hale & K. Sheard; 1 specimen, SAMA C8036 , Whalers Bay, Thistle Island , South Australia [approx. 35°00’S 136°11’E], 7 fms [12.8 m], 3 March 1941, K. Sheard .

Tasmania. 1 male, AM E.6521, Bass Strait , east coast of Flinders Island (40°00'S 148°30'E), 1909-1914, FIS Endeavour; 87 specimens, AM P.38829; 11 specimens, AM P.50876; 450 specimens, AM P.50877, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-386]; 549 specimens, AM P.51037, east of Fortescue Bay (43°06.7’S 148°13.6’E), 200 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-376]; 1 specimen, AM P.51224, east of Fortescue Bay (43°06.7’S 148°13.6’E), 200 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-393]; 1 specimen, AM P.57709, east of Fortescue Bay (43°09.36’S 148°13.6’E), 300 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-378]; 52 specimens, AM P.51015, east of Fortescue Bay (43°06.7’S 148°13.6’E), 200 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-356]; 17 specimens, AM P.50932, east of Fortescue Bay (43°06.7’S 148°13.6’E), 200 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-357]; 1 specimen, AM P.85717, off Babel Island (39°55'S 148°31'E), 25 m over a bottom depth of 51 m, horizontal plankton haul, 20 January 1939, CSIRO, FRV Warreen [29/39]; 8 specimens, AM P.51147, east of Fortescue Bay (43°09.36’S 148°13.6’E), 300 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-377]; 1 specimen, AM P.51139, east of Fortescue Bay (43°09.36’S 148°13.6’E), 300 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-359]; 2 specimens, AM P.51227, east of Fortescue Bay (43°06.7’S 148°13.6’E), 200 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-394]; 700 specimens, AM P.50891, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-390]; 771 specimens, AM P.51188; 41 specimens, AM P.51190, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-391]; 1820 specimens, AM P.51329, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 9–10 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-408]; 356 specimens, AM P.51315, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 9–10 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-409]; 2903 specimens, AM P.51033, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-372]; 11004 specimens, AM P.50821, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-354]; 3187 specimens, AM P.50866, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-371]; 188 specimens, AM P.51157, east of Fortescue Bay (43°06.7’S 148°13.6’E), 200 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-374]; 1 specimen, AM P.85712, Bass Strait , east of Flinders Island (40°01'S 148°02'E), m, FIS Endeavour, 1909-1914, FIS Endeavour; 67 specimens, AM P.46651, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-368]; 2 specimens, AM P.85711, north side of Cape Sorell (42°11.5’S 145°10.8’E), 13 m, baited trap, 27–28 April 1991, J.K. Lowry & S.J. Keable, Flying Scud [TAS-301]; 35 specimens, AM P.85716, Freycinet Peninsula , about 800 m east of Point Geographe (42°17.0'S 148°18.8'E), 45 m, baited trap, 30 April 1991 – 1 May 1991, J.K. Lowry & S.J. Keable, Flying Scud [TAS-337]; 13 specimens, AM P.50839, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-370]; 200 specimens, AM P.50915, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 9–10 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-405]; 1 specimen, AM P.85710, off the coast of Tasmania, Australia (42°00'S 146°45'E), 1909-1914, FIS Endeavour; 259 specimens, AM P.50884, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 8–9 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-387]; 9963 specimens, AM P.45772, east of Fortescue Bay , north of Hippolyte Rocks (43°06.7’S 148°03.45’E), 100 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-353]; 511 specimens, AM P.45741, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-350]; 47 specimens, AM P.51394, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 9–10 April 1994, J.K. Lowry & K. Dempsey, MV Martrudan [TAS-406]; 86 specimens, AM P.46644, mouth of Fortescue Bay (43°07.76’S 147°59.98’E), 50 m, baited trap, 16–17 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-352]; 2 specimens, AM P.51167, east of Fortescue Bay (43°07.36’S 148°13.75’E), 400 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-380]; 2 specimens, AM P.51173, east of Fortescue Bay (43°07.36’S 148°13.75’E), 400 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-382]; 1 specimen, AM P.51181, east of Fortescue Bay (43°08.96’S 148°15.36’E), 1000 m, baited trap, 17–18 April 1993, J.K. Lowry & P. Freewater, MV Tasmanian Enterprise [TAS-384]; 1 specimen, NMV J67769 , 5 km north-east of Mistaken Cape, Maria Island , Tasmania (42º37.0’S 148º12.5’E), 100 m, fine muddy bryzoan, epibenthic sled, 23 April 1985, RV Challenger [ MV TAS-31]; 2 specimens, NMV J67766 , 25 km north-east of Deal Island , Tasmania, eastern Bass Strait , Australia (39°16.8'S 147°33.2'E), 57 m, medium sand, epibenthic sled, 18 November 1981, RV Tangaroa [ BSS 174 S]; 1 specimen, NMV J67761 , 9 km south-south-west of Cape Adansan , Three Hummock Island, central Bass Strait, Australia (40°30.9'S 144°56'E), 27 m, very coarse sand, epibenthic sled, 2 November 1980, M. Gomon & G.C.B. Poore, FRV Sarda [ BSS 109 S]; 5 specimens, NMV J67762 , 9 km south-south-west of Cape Adansan , Three Hummock Island, central Bass Strait, Australia (40°30.9'S 144°56'E), 27 m, very coarse sand, epibenthic sled, 2 November 1980, M. Gomon & G.C.B. Poore, FRV Sarda [ BSS 109 S] .

Victoria. 1 specimen, NMV J67767 , south of Point Hicks (38°17.70'S 149°11.30'E), 400 m, coarse sand, gravel, mud, many sponges, WHOI epibenthic sled, 24 July 1986, M.F. Gomon et al., RV Franklin [ SLOPE 40 ]; 1 specimen, NMV J7469 , 51 km south-south-west of Cape Otway, western Bass Strait, Australia (39°16'S 143°17'E), 90 m, medium sand, dredge, 10 October 1980, G.C.B. Poore, HMAS Kimbla [BSS-73D]; 3 specimens, NMV J67764 , 15 km east of Cape Wellington, Wilsons Promontory, Victoria, eastern Bass Strait , Australia (39º03.2'S 146º39.5'E), 55 m, muddy fine sand, epibenthic sled, 18 November 1981, R. Wilson, RV Tangaroa [BSS-179S]; 1 specimen, NMV J7446 , 25 km west-south-west of Cape Otway, western Bass Strait, Australia (38°55'S 143°25'E), 67 m, coarse sand, dredge, G.C.B. Poore, 8 October 1980, HMAS Kimbla [BSS-53D]; 1 specimen, NMV J67763 , 70 km south-west of Cape Otway , western Bass Strait, Australia (39°26.3'S 143°06.8'E), 115 m, sand, epibenthic sled, 21 November 1981, R. Wilson , RV Tangaroa [BSS-194S] .

Western Australia. 5 specimens, AM P.78479, north-east of Dampier , drill platform, (19°46.28'S 115°20.03'E), 222 m, baited trap, 17 July 2008, H. Smith .

Description. Based on female, 18.9 mm, AM P.96595. Head, lateral cephalic lobe rounded; eyes reniform. Antenna 1 peduncular article 1 without anterodistal lobe; accessory flagellum not forming cap, 10-articulate, terminal article not offset; primary flagellum with strong 2-field callynophore; calceoli absent. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged, brush setae absent; flagellum long; calceoli absent. Labrum, epistome and upper lip fused, slightly concave proximally, with central bulge. Mandible molar setose with vestigial triturating surface; palp attached proximally, article 2 not broadened distally, article 3 blade-like. Maxilla 1 outer plate setal-tooth 7 present, cuspidate distally along inner margin; palp distal margin with apical robust setae. Maxilliped outer plate with 3 long apical robust seta.

Gnathopod 1 chelate; coxa reduced, significantly shorter than coxa 2, subquadrate; basis sparsely setose along anterior margin; ischium very long (length 4 × to 6 × breadth); carpus very long (length more than 4 × breadth), subequal in length to propodus, without posterior lobe; propodus margins subparallel, palm obtuse, entire, straight; dactylus simple. Gnathopod 2 propodus palm transverse to slightly acute, straight. Pereopod 4 coxa with a welldeveloped posteroventral lobe. Pereopod 5 coxa without distinct lateral ridge; basis broader than long, posterior margin not serrate. Pereopod 7 basis posterodistally produced less than halfway along merus.

Pleonite 3 without mid-dorsal carina, not produced dorsodistally, posterodorsal margin not produced. Epimeron 3 posterior margin smooth, posteroventral corner narrowly rounded. Urosomite 1 not projecting over urosomite 2, with anterodorsal notch and slightly rounded boss. Uropod 2 inner ramus without constriction. Uropod 3 peduncle without dorsolateral flange; outer ramus article 2 short, with strong plumose setae on both rami. Telson deeply cleft ; without dorsal robust setae; with 1 apical robust setae on each lobe.

Sexually dimorphic characters. Based on male, 17.0 mm, AM P.96594. Antenna 1 flagellum article 1 longer than female, with strong 2-field callynophore, stronger than female; calceoli present. Antenna 2 flagellum calceoli present.

Habitat. Marine.

Depth range. 3–1000 m (this study).

Feeding strategies. Scavenger, taken in baited traps.

Remarks. Stephonyx pirloti is a distinctive species. It differs from other species in the genus by the epistome which is fused and by the long first article on the mandibular palp. The gnathopod 2 carpus, as illustrated by Sheard (1938) was about 3.5 × as long as the propodus. In material we have examined from Kangaroo Island, the type locality, the carpus is about 2.5 × as long as the propodus. In a selection of material we found a range from 2.2 × to 2.8 × the propodus, well outside the length ratio of Sheard. The most frequent length ratio is about 2.5. In all other respects our material corresponds with the material of Sheard 1938.

Distribution. Australia. Coasts of New South Wales (this study); Flinders Islands, Victoria ( Chilton 1921); Gulf St Vincent, Kangaroo Island South Australia ( Sheard 1938; this study); Tasmania (this study); Western Australia (this study).

Figures

FIGURE 42. Stephonyx pirloti (Sheard, 1938), female, 18.9 mm, AM P. 96595, from off Wollongong, New South Wales, Australia.

FIGURE 43. Stephonyx pirloti (Sheard, 1938), female, 18.9 mm, AM P. 96595; male 17.0 mm, AM P. 96594, from off Wollongong, New South Wales, Australia. Scale bars: 0.5 mm.

FIGURE 44. Stephonyx pirloti (Sheard, 1938), female, 18.9 mm, AM P. 96595, from off Wollongong, New South Wales, Australia. Scale bars: 0.5 mm.