Thrombasia J.L. Barnard, 1966

Kilgallen, N. M. & Lowry, J. K., 2014, The Tryphosa group (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae), Zootaxa 3768 (5), pp. 501-545 : 525

Thrombasia J.L. Barnard, 1966

Thrombasia J.L. Barnard, 1966: 72 .― Ledoyer, 1986: 810.

Schisturella .― Barnard & Karaman, 1991: 526 (in part).

Type species. Thrombasia tracalero J.L. Barnard, 1966 , original designation.

Included species. Thrombasia includes six species: T. evalina sp. nov.; T. grabenis J.L. Barnard, 1967 ; T. rotundata (K.H. Barnard, 1926) ; T. saros sp. nov.; T. tracalero J.L. Barnard, 1966 ; T. umina sp. nov.

Diagnostic description. Antenna 1 flagellum article 1 lacking robust seta on distal margin; accessory flagellum forming cap. Antenna 2 flagellum articles 3–5 slender in female, article 3 enlarged in male; articles 3–5 with brush setae on the anterior margin. Mandibular incisor curved; molar a reduced column with convex triturating surface or proximally setose and distally triturating; palp attached midway. Maxilla 1 ST-7 serrate along the distomedial medial margin; ST-D slender, apically cuspidate. Maxilliped outer plate apical robust setae present. Gnathopod 1 subchelate; coxa slightly to greatly shorter than coxa 2, tapering distally; carpus slightly longer than propodus; propodus palm acute, straight. Pereopod 4 coxa with well developed posteroventral lobe. Uropod 2 inner ramus constricted. Uropod 3 rami plumose setae absent in female, present occasionally in adult male. Telson moderately cleft.

Remarks. The genus Thrombasia was established by Barnard (1966) for T. tracalero , and was subsequently placed in the synonymy of Schisturella by Barnard & Karaman (1991). However, we consider Thrombasia to be distinct from Schisturella based on the gnathopod 1 coxa, which is tapering and slightly reduced, not vestigial as in Schisturella . There are four other genera in the Tryphosa group with a gnathopod 1 coxa that is not vestigial. Of these, Thrombasia may be separated from Gronella by the gnathopod 1 carpus, which is longer than the propodus, from Tryphosa and Bruunosa in the tapering gnathopod 1 coxa, and from Glorieusella in the subchelate gnathopod 1.

Distribution. Pacific Ocean, South Atlantic Ocean.