Cedrosella cito, 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 : 5-7

Cedrosella cito sp. nov.

( Figs 2–4 )

Types. Holotype male, 4.6 mm, NMV J67525 , 76 km south of Point Hicks , Victoria, Australia (38°29.33'S 149°19.98'E), 1840 m, sandy mud, fine shell, WHOI epibenthic sled, 26 October 1988, coll. G.C.B. Poore and party, RV Franklin . Paratypes, 2 specimens, 3.0–4.0 mm, NMV J67526 , same collection details as holotype .

Type locality. South of Point Hicks , Victoria, Australia (38°29.33'S 149°19.98'E), 1840 m depth .

Etymology. Named for the barque Cito, which was swept onto rocks at Cape St. John, Bass Strait in April 1879; used as a noun in apposition.

Description. Based on holotype male, 4.6 mm, NMV J67525 . Head lateral cephalic lobe subtriangular, strongly produced, apically subacute; eyes apparently absent. Antenna 1 accessory flagellum not forming operculum, 3-articulate; primary flagellum with strong 2-field callynophore, robust setae present on proximal articles; calceoli present, small. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged; flagellum short, calceoli present. Labrum, epistome and upper lip separate; epistome produced equally with upper lip, concave; upper lip not produced. Mandible molar with asymmetrically reduced column, distally triturating; palp attached about midway or very slightly distally. Maxilla 1 outer plate setal-tooth 7 present, left and right symmetrical, cuspidate distally; palp distal margin with apical robust setae. Maxilliped outer plate with 1 long, slender apical robust seta.

Pereonites 1–7 dorsally smooth. Gnathopod 1 subchelate; coxa subtriangular, tapering distally with straight anterior margin, slightly shorter than coxa 2; basis sparsely setose along anterior margin; ischium short; carpus short, shorter than propodus, without posterior lobe; propodus margins subparallel, sparsely setose along posterior margin, palm transverse, entire, straight. Gnathopod 2 minutely subchelate, propodus palm transverse. Pereopod 4 coxa with a well-developed posteroventral lobe. 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 dorsodistally produced, acutely downturned. Epimeron 3 posterior margin smooth, posteroventral corner forming broad, upwardly-curved spine. Urosomite 1 dorsally straight. Uropod 2 inner ramus without constriction. Uropod 3 inner and outer rami well developed, without plumose setae on rami, outer ramus article 2 long. Telson deeply cleft, longer than wide, with 1 dorsal robust seta per lobe and 1 apical robust setae on each lobe.

Sexually dimorphic characters. Not known.

Remarks. Cedrosella cito sp. nov. is the second species described in the genus. It is easily distinguished from the type of the genus, C. fomes ( Barnard, 1967) , by the distinctive pleonite 3, which is dorsodistally acutely produced over urosomite 1 in addition to forming a strong curving spine on the posteroventral corner.

Depth range. 1840 m.

Distribution. Australia. Bass Strait.

Figures

FIGURE 2. Cedrosella cito sp. nov., habitus, paratype, male, 4.0 mm, NMV J67526, from 76 km south of Point Hicks, Victoria, Australia.

FIGURE 3. Cedrosella cito sp. nov., holotype, male, 4.6 mm, NMV J67525, from 76 km south of Point Hicks, Victoria, Australia. Scale: 0.1 mm.

FIGURE 4. Cedrosella cito sp. nov., holotype, male, 4.6 mm, NMV J67525, from 76 km south of Point Hicks, Victoria, Australia. Scale: gnathopods, pereopods, 0.2 mm; uropods, telson, 0.1 mm.