Sophrosyne californica, 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 : 9-10

Sophrosyne californica sp. nov.

Sophrosyne robertsoni . —J.L. Barnard, 1966: 72, figs 21, 22.

Type material. (not examined, material of J.L. Barnard, 1966, as S. robertsoni ) HOLOTYPE, female, 8.0 mm, LACM, 28.9 miles from China Point Light , Tanner Basin , southern California , east Pacific Ocean (32°33'36"N 118°55'40"W), green mud, Campbell grab, 1298 m, 29 January 1960, stn 6832 . PARATYPE, LACM, same data .

Type locality. 28.9 miles from China Point Light , Tanner Basin , southern California, east Pacific Ocean (32°33'36"N 118°55'40"W), 1298 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 medium length, length 1.5 x breadth; accessory flagellum medium length, 0.36 x primary flagellum, article 1 short, 1.7 x article 2; flagellum 9-articulate, without callynophore. Antenna 2 [peduncular article 3 unknown]; flagellum 8-articulate. Mandible incisors with straight margins; palp article 2 slender, 1.3 x article 3, with 2 distal A2-setae, D2-setae present, article 3 length 5.8 x breadth, with 2 distal D3-setae, with 4 apical E3-setae. Maxilla 1 outer plate with setal-teeth in a 2/3 arrangement. Maxilla 2 inner plate narrow, outer plate broader; inner plate length 0.64 x outer plate. Maxilliped inner plate subrectangular, without apical nodular robust setae; outer plate submarginal setae long, simple; palp article 2 slender, length 2.7 x breadth, 1.2 x article 3, article 3 slender, length 3.1 x breadth, dactylus with unguis absent. Gnathopod 1 basis length 2.2 x breadth, anterior margin with slender setae; ischium length 1 x breadth; merus, posterior margin lined with long slender setae; carpus length 0.6 x propodus; propodus length 1.9 x breadth, posterior margin slightly concave, with robust setae, palm margin straight, posterodistal corner with produced subacute spine bearing vestigial seta. Gnathopod 2 minutely subchelate; ischium length 3.25 x breadth; carpus long, length 3.8 x breadth, posterior margin straight; propodus subrectangular, long, length 2.7 x breadth; palm transverse, with concave, smooth margin. Pereopod 3 merus weakly expanded anteriorly. Pereopod 4 merus weakly expanded anteriorly. Pereopod 5 basis moderately expanded posteriorly; merus slightly expanded posteriorly. Pereopod 6 coxa small, slightly lobate posteriorly; merus slightly expanded posteriorly. Pereopod 7 basis posterior margin slightly rounded, minutely crenate, posteroventral margin rounded, posteroventral lobe not extending beyond ischium; merus not expanded posteriorly; propodus with setae along anterior margin. Epimeron 3 posterior margin with strong upturned spine above rounded posteroventral corner. Urosomite 1 with anterodorsal notch and rounded boss, without lateral flange. Uropod 1 rami subequal in length; outer ramus with 3 dorsal robust setae; inner ramus with 1 dorsal robust seta. Uropod 2 rami subequal in length; rami without robust setae. Uropod 3 peduncle length 1.5 x breadth; rami subequal in length. Telson longer than broad, length 1.2 x breadth, moderately cleft (62%), distal margins incised, with1 apical slender seta on each lobe.

Remarks. Sophrosyne californica shares with S. cantractia the same setal-tooth arrangement on the outer plate of maxilla 1, a vestigial seta on the posterodistal corner of the gnathopod 2 propodus and a curved posteroventral corner with a strong upturned tooth on epimeron 3. Sophrosyne californica differs from S. cantractia in the presence of D-setae on the mandibular palp, in the absence of apical nodular setae on the inner plate of the maxilliped and in the slender second article of the maxillipedal palp.

Distribution. Tanner Basin, eastern North Pacific Ocean in 1298 m depth.