Sophrosyne rodondo, Lowry & Stoddart, 2010

Lowry, J. K. & Stoddart, H. E., 2010, Sophrosynidae, a new family in the Lysianassoidea (Crustacea: Amphipoda) with a revision of the genus Sophrosyne, Zootaxa 2370 (1), pp. 1-35 : 29-30

Sophrosyne rodondo sp. nov.

( Figs 17 , 18 )

Type material. HOLOTYPE, female, 4.6 mm, MV J60734 , 66 km south of Rodondo Island , central Bass Strait, Australia (39°48.6'S 146°18.8'E), 82 m, sand, silt and mud, epibenthic sled, R. Wilson, 13 November 1981, RV Tangaroa , cruise 81- T-1 (stn BSS-158S) . PARATYPES: female, AM P.46681, same data; female, MV J 60735 , 100 km south-south-east of Cape Liptrap , central Bass Strait, Australia (39°45.9'S 145°33.5'E), 74 m, muddy fine sand, epibenthic sled, R. Wilson on RV Tangaroa , 13 November 1981, cruise 81- T-1 (stn BSS-156) .

Type locality. 66 km south of Rodondo Island , central Bass Strait, Australia (39°48.6'S 146°18.8'E), 82 m.

Etymology. The specific name refers to the type locality.

Diagnostic description. Head lateral cephalic lobe small, narrowly rounded; eyes round. Antenna 1 peduncular article 1 short, length 1.2 x breadth; accessory flagellum medium length, 0.46 x primary flagellum, article 1 long, 3 x article 2; flagellum 6-articulate, without callynophore. Antenna 2 peduncular article 3 0.6 x article 4; flagellum 6-articulate. Mandible incisors with slightly convex margins; palp article 2 slender, 1 x article 3, with 1 submarginal posterodistal A2-seta, without D2-setae, article 3 length 5.5 x breadth, without D3-setae, with 4 apical E3-setae. Maxilla 1 outer plate with setal-teeth in a 2/5 arrangement. Maxilla 2 inner plate narrow, outer plate broader; inner plate length 0.65 x outer plate. Maxilliped inner plate subrectangular, without apical nodular robust setae; outer plate submarginal setae long, simple; palp article 2 slender, length 2.3 x breadth, 1.1 x article 3, article 3 slender, length 2.4 x breadth, dactylus with unguis present. Gnathopod 1 basis length 1.8 x breadth, anterior margin with slender setae; ischium length 1 x breadth; merus, posterior margin lined with long slender setae; carpus length 0.45 x propodus; propodus length 1.9 x breadth, posterior margin slightly concave, with robust setae and simple, slender setae, palm margin straight, posterodistal corner with produced subacute spine bearing vestigial seta. Gnathopod 2 minutely subchelate; ischium length 3.4 x breadth; carpus long, length 3.7 x breadth, posterior margin straight; propodus subrectangular, long, length 2.2 x breadth; palm slightly acute, with convex margin, with minute robust setae. Pereopod 3 merus weakly expanded anteriorly. Pereopod 4 merus weakly expanded anteriorly. Pereopod 5 basis greatly expanded posteriorly; merus moderately expanded posteriorly. Pereopod 6 coxa small, slightly lobate posteriorly; merus expanded posteriorly. Pereopod 7 basis posterior margin slightly rounded, minutely crenate, posteroventral margin rounded, posteroventral lobe extending beyond ischium; merus not expanded posteriorly; propodus with setae along anterior margin. Epimeron 3 posterior margin with strong upturned spine above subquadrate posteroventral corner. Urosomite 1 with anterodorsal notch and rounded boss, with lateral flange. Uropod 1 rami subequal in length; outer ramus with 1 dorsal robust seta; inner ramus without dorsal robust setae. Uropod 2 rami subequal in length; rami without robust setae. Uropod 3 peduncle length 1.1 x breadth; rami subequal in length. Telson longer than broad, length 1.1 x breadth, moderately cleft (38%), distal margins rounded, with 1 apical slender setae on each lobe.

Remarks. Sophrosyne rodondo appears to be most similar to S. hispana . Both have the posteroventral lobe on the basis of pereopod 7 extending beyond the ischium and a curved posteroventral corner with strong upturned tooth on epimeron 3. They differ most noticeably in the shape of the basis of pereopods 5 and 6.

Distribution. Bass Strait, Australia in 74–82 m depth.

Figures

FIGURE 17. Sophrosyne rodondo sp. nov., holotype female, 5.0 mm, MV J60734, off Cape Naturaliste, Tasmania, Australia. Scales represent 0.1 mm.

FIGURE 18. Sophrosyne rodondo sp. nov., holotype female, 5.0 mm, MV J60734, off Cape Naturaliste, Tasmania, Australia. Scales for U1–3 and T represent 0.1 mm, remainder represent 0.2 mm.