Parachevreuxiella justi, Lowry & Stoddart, 2011

Lowry, J. K. & Stoddart, H. E., 2011, The new deep-sea families Cebocaridae fam. nov., Cyclocaridae fam. nov. and Thoriellidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea), Zootaxa 2747 (1), pp. 53-68 : 63-65

Parachevreuxiella justi sp. nov.

( Figs 8–10 )

Type material. Holotype, male, 21.5 mm, MV J15798 , south of Point Hicks , Victoria, Australia, 38°27.20'S 149°09.70'E to 38°24.93'S 149°03.75'E, 1720 m over bottom depth of 1720–1800 m, rectangular midwater trawl, 22 July 1986, M.F. Gomon et al. on RV Franklin, stn SLOPE 24 .

Type locality. South of Point Hicks , Victoria, Australia, 38°27.20'S 149°09.70'E to 38°24.93'S 149°03.75'E, 1720 m over bottom depth of 1720–1800 m.

Etymology. The species is named for Jean Just who recognised this specimen in the unsorted SLOPE material.

Diagnostic description. Head much deeper than long, narrow, extending well below insertion of antenna 2, lateral cephalic lobe small, narrowly rounded; rostrum absent; eyes round. Antenna 1 accessory flagellum absent; flagellum 22-articulate, with callynophore, but without aesthetascs; without calceoli. Antenna 2 flagellum 22- articulate, without calceoli. Epistome and upper lip fused; produced into broad step. Mandible asymmetrical, incisors large, left with straight margin, minutely serrate, right with straight smooth margin; lacinia mobilis absent; accessory setal row absent; molar absent; mandibular palp absent. Maxilla 1 inner plate tapering distally, with reduced row of pappose setae along medial margin; outer plate with 7 setal-teeth in modified 8/3 crown arrangement; palp large, 2-articulate, without apical setae. Maxilla 2 inner plate very broad, with round lateral margin covered in long fine setae; outer plate narrow, tapering distally. Maxilliped inner plate large; outer plate large, subovate; palp vestigial, 1-articulate.

Gnathopod 1 weakly subchelate; coxa vestigial; basis short, broad; ischium short, length 1.1 × breadth; carpus short, length 1.3 × breadth, shorter than, (0.6 ×) propodus; dactylus simple, extremely reduced. Gnathopod 2 minutely subchelate; coxa vestigial; dactylus vestigial.

Pereopod 3 coxa large; propodus without posterodistal spur; dactylus long, slender, curved. Pereopod 4 coxa deeper than wide; propodus without posterodistal spur; dactylus long, slender, curved. Pereopod 5 coxa bilobate, posterior lobe strongly produced ventrally; basis linear; propodus without posterodistal spur. Pereopod 6 coxa large, strongly lobate posteriorly; basis linear, slightly broader than basis of pereopod 5; propodus without posterodistal spur; dactylus long, slender, curved. Pereopod 7 basis linear with slight posteroproximal bulge; propodus curved, without posterodistal spur; dactylus long, slender.

Epimeron 3 posteroventral corner narrowly rounded. Urosomites 1 and 2 free, 3 absent; urosomites 1 and 2 dorsally smooth. Uropod 1 uniramous; ramus narrow, length 5 × breadth and 0.7 × length of peduncle. Uropod 2 uniramous; ramus narrow, length 7 × breadth, as long as peduncle. Uropod 3 absent. Telson absent .

Remarks. Parachevreuxiella justi is very similar to P. lobata despite their great geographical separation. They can be distinguished by the deeper than wide coxa 4 in P. justi (wider than deep in P. lobata Andres, 1987 ) and in the ratios and shapes of uropods 1 and 2.

Distribution. South-west South Pacific Ocean in 1720–1800 m depth.

Figures

FIGURE 8. Parachevreuxiella justi sp. nov. Holotype male, 21.5 mm, MV J15798, south of Point Hicks, Victoria, Australia.

FIGURE 9. Parachevreuxiella justi sp. nov. Holotype male, 21.5 mm, MV J15798, south of Point Hicks, Victoria, Australia.

FIGURE 10. Parachevreuxiella justi sp. nov. Holotype male, 21.5 mm, MV J15798, south of Point Hicks, Victoria, Australia.