Paralysianopsis cf. jebbi ( Lowry & Stoddart, 1995b )

Lowry, J. K. & Kilgallen, N. M., 2014, New tryphosine amphipods from Australian waters (Crustacea, Amphipoda, Lysianassoidea, Lysianassidae, Tryphosinae), Zootaxa 3844 (1), pp. 1-64 : 32-33

Paralysianopsis cf. jebbi ( Lowry & Stoddart, 1995b)

( Fig. 23 )

? Rhinolabia jebbi Lowry & Stoddart, 1995b: 121 , figs 13, 14.

Types. Holotype, female with non-setose oostegites, 5.2 mm, AM P.41577 . Paratypes, 10 specimens, AM P.41578.

Type locality. 0.75 km east of Planet Rock , Astrolabe Bay, Papua New Guinea (5°15.48’S 149°49.14’E), about 500 m depth .

Material examined. 4 specimens, AM P.51111, east of Fortescue Bay , Tasmania, Australia (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] ; 2 specimens, AM P.51112, east of Fortescue Bay , Tasmania, Australia (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] .

Description. Head lateral cephalic lobe narrowly rounded; eyes oval. Antenna 1 accessory flagellum not forming operculum; primary flagellum with weak 2-field callynophore, robust setae absent from proximal articles; calceoli absent. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged, brush setae absent; flagellum short, calceoli absent. Labrum, epistome and upper lip separate; epistome less produced than upper lip, straight; upper lip strongly produced, rounded. Mandible molar strongly setose with a vestigial distal triturating surface. Maxilla 1 outer plate setal-tooth 7 present, left and right symmetrical, cuspidate distally; palp serrate along outer half of distal margin, without apical robust setae. Maxilliped outer plate with apical robust setae absent; palp article 4 well-developed.

Pereonites 1–7 dorsally smooth. Gnathopod 1 very weakly subchelate, appearing simple; coxa large, about as long as coxa 2, subrectangular with straight anterior margin; basis sparsely setose along anterior margin; ischium short; carpus short, subequal in length to propodus, without posterior lobe; propodus small, sparsely setose along posterior margin, palm extremely acute, entire, straight. Gnathopod 2 propodus palm obtuse, with minutely serrate pad on posterior corner. Pereopod 5 basis longer than broad, not posteroproximally excavate, 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 produced, narrowly rounded. Uropod 2 inner ramus with slight constriction. Uropod 3 inner and outer rami well developed, outer ramus article 2 long, without plumose setae on rami. Telson entire , apically truncate, slightly concave, without dorsal robust setae, with single subapical robust seta on each corner.

Remarks. The only difference we can see between P. jebbi and the current material is the broader merus on pereopod 5 in the Tasmanian specimens. This is a very large range extension with no records in between, but P. jebbi occurs at 500 m in Papua New Guinea and P. cf. jebbi occurs at 200 m in Tasmania, indicating similar environments.

Depth range. 200–500 m.

Distribution. Australia. Tasmania (this study). Papua New Guinea. Astrolabe Bay, Madang ( Lowry & Stoddart 1995b).

Figures

FIGURE 23. Paralysianopsis cf. jebbi (Lowry & Stoddart, 1995), head, G1 from specimen ‘a’, AM P.51112; pereopod 5 from specimen ‘b’, AM P.51112, from east of Fortescue Bay, Tasmania. Scale bars: head, 0.2 mm; G1, P5, 0.1 mm.