Parschisturella medora, Lowry & Kilgallen, 2014

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 : 54-57

Parschisturella medora sp. nov.

( Figs 33–35 )

Types. Holotype, female, 11.0 mm, NMV J67756 , 96 km south of Point Hicks , Victoria, Australia (38°40.29'S 149°18.06'E), 2900 m, compacted clay, WHOI epibenthic sled, 25 October 1988, G.C.B. Poore et al., RV Franklin [ SLOPE 66 ] . Paratypes: 8 specimens, 4.0– 8.7 mm, NMV J67757 ; 1 female, 10.3 mm, NMV J67758 ; 6 specimens, 5.4–10.2 mm, NMV J17167 , same collection details as holotype.

Type locality. 96 km south of Point Hicks , Victoria, Australia (38°40.29'S 149°18.06'E), 2900 m depth .

Etymology. Named for the brig Medora which caught fire off the Tamar Heads, Tasmania, on the morning of 31 July 1854 and was scuttled after cutting away the mast; used as a noun in apposition.

Additional material examined. Tasmania. 18 specimens, AM P.71839, east of Cape Naturaliste , Tasmania, Australia (40°45.93’S 149°1.62’E), 2400–2500 m, sledge, 10 December 1986, P.A. Hutchings, W.F. Ponder & R. T. Springthorpe , RV Franklin [FR1086-04]; 1 specimen, NMV J67760 , 48 km east-north-east of Cape Tourville (42°00.25'S 148°43.55'E to 41°57.77'S 148°42.08'E), 1264– 1130 m, gravel with lumps of sandy mud aggregate, WHOI epibenthic sled, 30 October 1988, G.C.B. Poore et al., RV Franklin [ SLOPE 81 ] .

Victoria. 1 specimen, NMV J67759 , 67 km south of Point Hicks (38°23.95'S 149°17.02'E), 1277 m, fine mud, WHOI epibenthic sled, 25 October 1988, G.C.B. Poore et al., RV Franklin [ SLOPE 67 ] .

Description. Based on holotype, female, 11.0 mm, NMV J67756 . Head, lateral cephalic lobe subtriangular, apically subacute. Antenna 1 peduncular article 1 without anterodistal lobe; accessory flagellum not forming cap, 5-articulate, terminal article not offset; primary flagellum with strong 1-field callynophore; robust setae absent from proximal articles; calceoli absent. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged; flagellum short; calceoli absent. Labrum, epistome and upper lip fused, concave; ventrally produced, acute apically. Mandible incisor large, left and right very slightly asymmetrical; molar with asymmetrically reduced column, proximally setose, distally triturating; palp attached slightly distally, article 2 margins subparallel, article 3 bladelike. Maxilla 1 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 6 long, apical robust setae.

Gnathopod 1 weakly subchelate; coxa large, about as long as coxa 2, distally subovate; basis moderately to densely setose along anterior margin; ischium long (length 2 × to 4 × breadth); carpus long (length 2 to 4 × breadth), longer than propodus, without posterior lobe; propodus margins tapering distally; dactylus with large subapical spine. Gnathopod 2 propodus palm slightly obtuse; dactylus fitting palm. Pereopod 4 coxa with a welldeveloped posteroventral lobe. Pereopod 5 coxa without distinct lateral ridge; basis about as long as broad, posterior margin weakly 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 acutely produced, forming weak spine. Urosomite 1 not projecting over urosomite 2, with a weakly produced, broadly truncated boss. Uropod 2 inner ramus without constriction. Uropod 3 peduncle without dorsolateral flange; outer ramus article 2 short, without plumose setae on rami. Telson deeply cleft , without dorsal robust setae, with 1 apical robust setae on each lobe.

Sexually dimorphic characters. Male unknown.

Depth range. 1264–2900 m.

Remarks. The Australian species Parschisturella medora and P. piloti both have weakly subchelate first gnathopods. The most conspicuous differences between these species is the posteroventral corner of epimeron 3 (forming a small spine in P. medora and with a small notch above the corner in P. piloti ), and the dorsal margin of urosomite 1 (a weakly produced, broadly truncated boss in P. medora and a rounded margin in P. piloti ).

Distribution. Australia. Coasts of Victoria and Tasmania, Bass Strait.

Figures

FIGURE 33. Parschisturella medora sp. nov., holotype, female, 11.0 mm, NMV J67756, from south of Point Hicks, Victoria, Australia.

FIGURE 34. Parschisturella medora sp. nov., holotype, female, 11.0 mm, NMV J67756, from south of Point Hicks, Victoria, Australia. Scale bars: 0.2 mm.

FIGURE 35. Parschisturella medora sp. nov., holotype, female, 11.0 mm, NMV J67756, from south of Point Hicks, Victoria, Australia. Scale bars: gnathopods, pereopods, 0.5 mm; uropods, telson, 0.2 mm.