Fissarcturus argentinensis n. sp. (Valvifera, Isopoda) is described from the Mar del Plata submarine canyon. This species can be separated from other species of the genus by: (1) its medium-sized eyes, (2) the number and arrangement of spines on the body surface, and (3) the pleopod I with the endopod smaller than the exopod and lacking plumose setae on both rami. The distribution of F. patagonicus (Ohlin, 1901) is extended, and the male is described and illustrated for the first time. Remarks on the penial plate, a character that has received little attention in the taxonomy of the genus, are provided. The distribution data of the species currently assigned to Fissarcturus are compiled and updated. A general trend of eye size reduction with depth is suggested for the members of this genus.

Fissarcturus argentinensis ñ。sp。（Valvifera，Isopoda）是从马德普拉塔海底峡谷描述的。可通过以下方式将该物种与该属的其他物种分开：（1）中型眼睛，（2）体表上棘的数量和排列，以及（3）内足比外足小的内足的I而且在两个拉米上都没有羽状刚毛。Patagonicus（Ohlin，1901）的分布得到扩展，并且首次描述了雄性。提供了在阴茎板上的注释，该字符在属的分类学中很少受到关注。当前分配给费氏rc的物种的分布数据被编译和更新。对于该属的成员，建议眼睛深度随深度而减小的总体趋势。