Paralysianopsis ruffoi, Lowry & Kilgallen, 2014

Lowry, J. K. & Kilgallen, N. M., 2014, New tryphosine amphipods from Australian waters (Crustacea, Amphipoda, Lysianassoidea, Lysianassidae, Tryphosinae), Zootaxa 3844 (1), pp. 1-64 : 37-40

Paralysianopsis ruffoi sp. nov.

( Figs 27 , 28 )

Types. Holotype, female with non-setose oostegites, 2.7 mm, AM P.69297, north end of Fannie Bay , west end of East Point, Darwin, Northern Territory, Australia (11°24.5'S 130°48.5'E), 8–10 m, encrusting ascidian Didemnum psammatodes , hand collected on scuba, 26 October 1982, J.K. Lowry, stn NT-97 . Paratypes: 1 male, 1.8 mm, AM P.69298; 6 specimens, 1.2–2.4 mm, AM P.69299, north end of Fannie Bay , west end of East Point, Darwin, Northern Territory, Australia (11°24.5'S 130°48.5'E), 8–10 m, encrusting ascidian Didemnum psammatodes , hand collected on scuba, 26 October 1982, J.K. Lowry, stn NT-97 .

Additional material examined. Northern Territory. 1 male, AM P.69374, reef at west end of Oxley Island (11°00'S 132°49'E), 5 m, Halimeda sp. , 20 October 1982, J.K. Lowry, stn NT-78 ; 1 male, AM P.69375, patch reef on north side of New Year Island (10°54'S 133°02'E), 10 m, hydroids on coral, 14 October 1982, G.C.B. Poore, stn NT-17 .

Type locality. North end of Fannie Bay , west end of East Point, Darwin, Northern Territory, Australia (11°24.5'S 130°48.5'E), 8–10 m depth .

Etymology. Named for Sandro Ruffo, in appreciation of his contribution to lysianassoid taxonomy.

Description. Based on holotype, female, 2.7 mm, AM P.69297. Head lateral cephalic lobe broadly rounded; eyes oval. Antenna 1 accessory flagellum not forming operculum; primary flagellum with weak 1-field callynophore, robust setae absent from proximal articles; calceoli absent. Antenna 2 peduncle weakly geniculate between articles 3–4; article 3 short; articles 3 to 5 not enlarged, brush setae absent; flagellum short, calceoli absent. Labrum, epistome and upper lip fused, proximally concave distally produced and rounded. Mandible molar weakly setose with a reduced triturating surface. Maxilla 1 outer plate setal-tooth 7 present, left and right symmetrical, cuspidate distally; palp distal margin smooth, without apical robust setae. Maxilliped outer plate apical robust setae absent.

Pereonites 1–7 dorsally smooth. Gnathopod 1 weakly subchelate; coxa large, about as long as coxa 2, subrectangular with slightly concave anterior margin; basis not setose along anterior margin; ischium short; carpus short, subequal in length to propodus, without posterior lobe; propodus small, weakly setose along posterior margin, palm acute, straight, entire. Gnathopod 2 propodus palm transverse to slightly obtuse. Pereopod 5 basis slightly longer than broad, not posteroproximally excavate, posterior margin not serrate. Pereopod 7 basis posterodistally produced, not reaching merus.

Pleonite 3 without mid-dorsal carina, not produced dorsodistally, posterodorsal margin not produced. Epimeron 3 posterior margin smooth, posteroventral corner broadly 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 , as long as wide, apically truncate, with 2 subapical robust setae.

Sexually dimorphic characters. Based on paratype, male, 1.8 mm, AM P.69298. Head lateral cephalic lobes narrowly rounded to subacute. Antenna 1 flagellum article 1 broader than female, with strong 2-field callynophore.

Remarks. Paralysianopsis ruffoi is very similar to P. mazamoz , but P. ruffoi has no apical robust setae or serrate margin on the palp of maxilla 1 (vestigial robust setae and well-develop serrate margin in P. mazamoz ) and P. ruffoi has a broadly rounded posteroventral corner on epimeron 3 (produced and narrowly rounded in P. mazamoz ).

Depth range. 5–10 m.

Distribution. Australia. Northern Territory.

Figures

FIGURE 27. Paralysianopsis ruffoi sp. nov., holotype, female, 2.7 mm, AM P.69297; paratype, male, 1.8 mm, AM P.69298 Fannie Bay, Darwin, NT. Scale: 0.05 mm.

FIGURE 28. Paralysianopsis ruffoi sp. nov., holotype, female, 2.7 mm, AM P.69297, Fannie Bay, Darwin, NT. Scale: 0.1 mm.