Hippomedon rodericki Moore, 1989

Kilgallen, N. M. & Lowry, J. K., 2015, The genus Hippomedon in Australian waters (Crustacea, Amphipoda, Lysianassidae, Tryphosinae), Zootaxa 3926 (3), pp. 377-395 : 385-390

Hippomedon rodericki Moore, 1989

( Figs 8–10 )

Hippomedon rodericki Moore, 1989: 1444 , figs 1–3.— Lowry & Stoddart, 2003: 166.

Types. Holotype male, 8.5 mm, AM P.39389.

Type locality. Tasmania, off Burnie (41°02'S 146°00'E), circa 15 m, stones & sand, April 1986, Marine Ecological Surveys Ltd, Faversham, Kent, sample no. 29.

Additional material examined. New South Wales. 1 female, AM P.69717, Botany Bay (33°59.33'S 151°12.66'E), 10 m, 16 January 1975, NSW State Fisheries [BB-817]; 1 male, AM P.69718, Botany Bay (33°58.83'S 151°11.75'E), 6 m, 12 February 1975, NSW State Fisheries [BB-864]; 1 specimen, AM P.41957, Botany Bay, south of airport runway extension (33°58.13'S 151°11.16'E), 5 m, Smith-McIntyre Grab, 6–7 April 1992, Australian Museum party [NSW-767]; 2 specimens, AM P.44302, off Wollongong (34°26.53'S 150°57.98'E), 50 m, baited trap, Globigerina ooze, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-939]; 3 specimens, AM P.44314, off Wollongong (34°26.53'S 150°57.98'E), 50 m,baited trap, Globigerina ooze, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-940]; 2 specimens, AM P.44332, off Wollongong (34°26.53'S 150°57.98'E), 50 m,baited trap, Globigerina ooze, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-958]; 5 specimens, AM P.48426, north-east of Coffs Harbour (30°15.93'S 153°21.9'E), 100 m, baited trap, 9–10 September 1994, J.K. Lowry & K. Dempsey, MV Carrie Ann [NSW-1006]; 2 specimens, AM P.55973, north-east of Coffs Harbour (30°15.75'S 153°21.98'E), 98 m,baited trap, 12–13 August 1993, P.B. Berents, R.T. Springthorpe & W. Vader, MV Cheryl Lee [NSW-885]; 1 male, AM P.69712, east of Long Reef Point (33°46'S 151°43'E), 176 m, dredge, 5 December 1977, FRV Kapala [K 77-23-01]; 4 specimens, AM P.69713, east of Long Reef Point (33°46'S 151°43'E), 176 m, dredge, 0 5 December 1977, FRV Kapala [K 77-23-01]; 2 specimens, AM P.69714, east of Broken Bay (33°35–34'S 151°41'E), 135 m, 10 February 1986, FRV Kapala [K 86- 01-03]; 1 female, AM P.69715, east of Long Reef (33°43–44'S 151°46'E), 174 m, epibenthic sled, 20 December 1985, J.K. Lowry & R.T. Springthorpe, FRV Kapala [K 85-21-08]; 7 specimens, AM P.69716, east of Long Reef (33°43–44'S 151°46'E), 174 m, epibenthic sled, 20 December 1985, J.K. Lowry & R.T. Springthorpe, FRV Kapala [K 85-21-08]; 1 specimen, AM P.69719, off coast (33°50', 151°20'E), 73–183 m, from stomach of Jackass Fish ( Nemadactylus macropterus ), July 1939, A.C.S.; 1 female, AM P.69720, Bass Point (34°36'S 150°54'E), 45–50 m, Smith-McIntyre Grab, 29 October 1990 – 14 Nov 1990, The Ecology Lab for RMI /Pioneer Project [3-27]; 1 specimen, AM P.69721, Bass Point (34°36'S 150°54'E), 35–40 m, Smith-McIntyre Grab, 3–18 January 1991, The Ecology Lab for RMI /Pioneer Project [4-213]; 1 specimen, AM P.69722, Bass Point (34°36'S 150°54'E), 25–30 m,Smith-McIntyre Grab, 1 February 1990, The Ecology Lab for RMI /Pioneer Project [S1R1]; 1 specimen, AM P.69723, Wattamolla, off Providential Head (34°08'S 151°08.5'E), 35–40 m, Smith-McIntyre Grab, 15 January 1990, The Ecology Lab for RMI /Pioneer Project [W 9]; 1 specimen, AM P.83395, Jervis Bay (35°01.13'S 150°45.6'E), 14 m, Van Veen Grab, 24 June 2008, Geoscience Australia, M. McArthur, HMAS Kimbla [GA0312/ JB_45]; 1 specimen, AM P.22007, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 24 January 1973, Australian Museum Shelf Benthic Survey [III]; 4 specimen, AM P.22008, 1.6 km east of Malabar sewage outlet (33°58.25’S 151°17’E), 66 m, 26 June 1973, Australian Museum Shelf Benthic Survey [III]; 1 specimen, AM P.22009, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 26 March 1973, Australian Museum Shelf Benthic Survey [Stn III]; 1 specimen, AM P.22010, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 31 July 1973, Australian Museum Shelf Benthic Survey [Stn. III]; 2 specimen, AM P.22011, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 23 May 1973, Australian Museum Shelf Benthic Survey [III]; 1 specimen, AM P.22012, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 19 April 1973, Australian Museum Shelf Benthic Survey [III]; 1 specimen, AM P.22013, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 26 March 1973, Australian Museum Shelf Benthic Survey [Stn III]; 5 specimen, AM P.22014, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 30 August 1973, Australian Museum Shelf Benthic Survey [Stn. III]; 1 specimen, AM P.22015, 1.6 km east of Malabar sewage outlet (33°58.25'S 151°17'E), 66 m, 24 September 1973, Australian Museum Shelf Benthic Survey [III]; 2 specimen, AM P.22016, 2 km east of Long Bay (33°58.33'S 151°17.82'E), 127 m, 24 April 1973, Australian Museum Shelf Benthic Survey [IV]; 1 specimen, AM P.22017, 2 km east of Long Bay (33°58.33'S 151°17.82'E), 127 m, 27 September 1973, Australian Museum Shelf Benthic Survey [IV]; 1 specimen, AM P.22018, 2 km east of Long Bay (33°58.33'S 151°17.82'E), 127 m, 22 August 1973, Australian Museum Shelf Benthic Survey [IV]; 1 specimen, AM P.22019, 2 km east of Long Bay (33°58.33'S 151°17.82'E), 127 m, 5 December 1973, Australian Museum Shelf Benthic Survey [IV]; 1 specimen, AM P.22020, 2.3 km south-east of Malabar (33°58.45'S 151°18.68'E), 134 m, 26 January 1974, Australian Museum Shelf Benthic Survey [V]; 1 specimen, AM P.22021, 2.3 km south-east of Malabar (33°58.45'S 151°18.68'E), 134 m, 26 April 1973, Australian Museum Shelf Benthic Survey [V]; 1 specimen, AM P.22022, 2.3 km south-east of Malabar (33°58.45'S 151°18.68'E), 134 m, 24 Oct 1973, Australian Museum Shelf Benthic Survey [V]; 3 specimen, AM P.22023, 2.3 km south-east of Malabar (33°58.45'S 151°18.68'E), 134 m, August 1973, Australian Museum Shelf Benthic Survey [V]; 1 specimen, AM P.22024, 2.3 km south-east of Malabar (33°58.45’S 151°18.68’E), 134 m, 30 March 1973, Australian Museum Shelf Benthic Survey [V]; 2 specimen, AM P.22025, east of Malabar (33°58.76'S 151°17.05'E), 66 m, 19 February 1973, Australian Museum Shelf Benthic Survey [Stn. 26]; 1 specimen, AM P.22026, east of Malabar (33°57.92'S 151°18.06'E), 75 m, 20 February 1973, Australian Museum Shelf Benthic Survey [Stn. 31]; 1 specimen, AM P.22031, 2km east of Magic Point (33°57.66'S 151°16.86'E), 39 m, medium sand bottom with shell fragments, 17 May 1972, Australian Museum Shelf Benthic Survey [D2]; 1 specimen, AM P.22032, east of Malabar (33°58.16'S 151°17.16'E), 68 m, 21 February 1973, Australian Museum Shelf Benthic Survey [Stn. 32]; 1 specimen, AM P.24046, 1.5 km east of Belmont Beach (33°02.6'S 151°40.93'E), 23 m, 18 March 1975, Australian Museum Hunter District Water Board Survey [ HDWBS 09010301]; 1 specimen, AM P.24047, 1.5 km east of Burwood Beach (32°57.52'S 151°44.72'E), 28 m, mud with gravel, 16 December 1975, Australian Museum Hunter District Water Board Survey [ HDWBS 06010304].

Tasmania. 1 specimen, AM P.51087, 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]; 5 specimens, AM P.69635, off Babel Island (39°55'S 148°31'E), 25 m over bottom depth 51 m, horizontal plankton haul, 20 January 1939, CSIRO, FRV Warreen [29/39]; 1 specimen, NMV J67795 , central Bass Strait, 6 km north-east of Stanley (40°48.8'S 145°22'E), 22 m, fine sand, 4 November 1980, M. Gomon & G.C.B. Poore, FRV Sarda [BSS-114]; 1 specimen, NMV J2431, Robbins Island, 5 km east of Cape Edie (40°41.8'S 145°07'E), 16 m, fine shelly sand, epibenthic sled, 3 November 1980, M. Gomon & G.C.B. Poore, FRV Sarda [BSS-110S].

Victoria. 1 specimen, NMV J3297, Port Phillip Bay, Hobsons Bay (37°51’S 144°56’E), 10.3 m, Smith- McIntyre grab, February 1975 – January 1986, G.C.B. Poore & S.F. Rainer [ PBES 137]; 1 male, NMV J67796 , western Bass Strait, 32 km south-south-west of Cape Otway, (39°09'S 143°26'E), 85 m, coarse carbonate sand, dredge, 8 October 1980, G.C.B. Poore, HMAS Kimbla [BSS-55D]; 1 specimen, NMV J67797 , central Bass Strait, 100 km south-south-east of Cape Liptrap (39°45.9'S 145°33.5'E), 74 m, muddy fine sand, epibenthic sled, 13 November 1981, R. Wilson, RV Tangaroa [BSS-156S]; 2 specimens, NMV J67798 , eastern Bass Strait, 50 km south-west of Lakes Entrance (38°03'S 147°50'E), 45 m, epibenthic sled, 31 July 1983, M. Gomon & R. Wilson, FV Silver Gull [BSS-212S]; 1 male, NMV J67799 , western Bass Strait, 31 km south-south-west of Cape Otway (39°08'S 143°24'E), 77 m, medium sand, 8 October 1980, Smith-McIntyre grab, G.C.B. Poore, HMAS Kimbla [stn BSS-56G]; 16 specimens, NMV J67800 , western Bass Strait, 26 km south-west of Cape Otway (39°01.0'S 143°22.1'E), 84 m, medium sand, dredge, 31 January 1981, M. Gomon et al., FRV Hai Kung [BSS-120D]; 1 specimen, NMV J67801 , western Bass Strait, 25 km east-south-east of Cape Otway (39°59'S 143°47'E), 81 m, sand, Smith-McIntyre grab, 7 October 1980, G.C.B. Poore, HMAS Kimbla [BSS-49G]; 1 specimen, NMV J67802 , central Bass Strait, 25 km south of Aireys Inlet (38°44.6'S 144°09.0'E), 77 m, fine sand, Smith-McIntyre grab, 19 November 1981, R. Wilson, RV Tangaroa [BSS-182G]; 1 specimen, NMV J67803 , western Bass Strait, 15 km south-west of Point Reginald (38°50.0'S 143°07.5'E), 69 m, fine sand, 20 November 1981, R. Wilson, RV Tangaroa [BSS-186]; 3 specimens, NMV J67804 , western Bass Strait, 70 km south-west of Cape Otway (39°26.3'S 143°06.8'E), 115 m, sand, epibenthic sled, 21 November 1981, R. Wilson, RV Tangaroa [BSS-194S]; 8 specimens, NMV J2432, western Bass Strait, 25 km south of Cape Otway (39°06'S 143°35.8'E), 95 m, fine sand, 31 January 1981, M. Gomon et al., FRV Hai Kung [BSS-118].

Description. Based on ovigerous female, 15.2 mm, AM P.69717. Head, lateral cephalic lobe subtriangular, apically subacute. Antenna 1 peduncular article 1 without anterodistal lobe; article 2 without anterodistal lobe; accessory flagellum present, 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 3 to 5 not enlarged; flagellum long, calceoli absent. Labrum (epistome and upper lip) separate; epistome produced equally with upper lip, slightly rounded; upper lip not produced. Mandible molar columnar, with subcircular fully triturating surface. Maxilla 1 inner plate with 1 large apical pappose seta and 7 smaller pappose setae along inner margin;outer plate setal-tooth 7 present, left and right symmetrical, cuspidate distally along inner margin; palp distal margin with apical robust setae. Maxilliped outer plate with 1 long, slender apical robust setae.

Gnathopod 1 subchelate; coxa large, about as long as coxa 2, subrectangular with straight anterior margin; basis moderately setose along anterior margin; ischium short; carpus long (length 3.0 × width), longer than propodus, without posterior lobe; propodus small, margins subparallel, sparsely setose along posterior margin, palm moderately acute, entire, straight. Gnathopod 2 propodus palm slightly acute and concave. Pereopod 4 coxa posteroventral lobe well-developed. Pereopod 5 coxa without distinct lateral ridge, basis about as long as broad, not posteroproximally excavate, posterior margin weakly serrate, posterior margin without mid-central spine, without posteroventral lobe or spine. Pereopod 7 basis posterodistally produced less than halfway along merus, not posterodistally excavate.

Epimeron 2 posteroventral corner producing small spine. Epimeron 3 posterior margin smooth, posteroventral corner produced into strong spine with notch at base. Urosomite 1 not projecting over urosomite 2, dorsally straight. Uropod 2 rami subequal in length, inner ramus without constriction. Uropod 3 slender; peduncle without dorsolateral flange; inner and outer rami well developed, outer ramus article 2 short, with plumose setae on both rami. Telson deeply cleft, with 2 or 3 dorsal robust setae per lobe, and 1 apical robust seta on each lobe.

Sexually dimorphic characters. Based on male, 13.5 mm, AM P.69718. Antenna 1 flagellum calceoli present, small. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged; flagellum long, calceoli present. Uropod 3 slender; peduncle without dorsolateral flange; inner and outer rami well developed, outer ramus article 2 short, with plumose setae on both rami, more developed than the female.

Depth range. 5– 200 m.

Remarks. Moore (1989) described the male holotype as lacking calceoli on the antennae. With more material available to us, we confirm that males do have small calceoli on both antenna 1 and 2. The extent of the excavation on the palm of gnathopod 2 seems to be variable from weakly to strongly concave.

Distribution. Australia. Eastern and south-eastern coasts from Coffs Harbour, New South Wales, to Fortescue Bay, Tasmania, and Bass Strait.

Figures

FIGURE 8. Hippomedon rodericki P. G. Moore, 1989, male, 13.5 mm, AM P. 69718, from Botany Bay, New South Wales.

FIGURE 9. Hippomedon rodericki P. G. Moore, 1989, ovigerous female, 15.2 mm, AM P. 69717; male, 13.5 mm, AM P. 69718, both from Botany Bay, New South Wales. Scale bars: 0.2 mm.

FIGURE 10. Hippomedon rodericki P. G. Moore, 1989, ovigerous female, 15.2 mm, AM P. 69717, from Botany Bay, New South Wales. Scale bars: 0.5 mm.