Abstract
A new valviferan isopod-Edotia dotiae sp. nov.- is described from the shallow coastal waters of Argentine Patagonia. The specimens were collected during three different expeditions in the Chubut and Santa Cruz provinces and in the Beagle Channel. The new species is distinguished from other Edotia species by the presence of two dorsal lobes on the head, a distally protruding pleotelson and uropods with elongated endopods reaching the tip of the pleotelson. In addition, it displays discrete patches of fluted tubercles on its dorsal and lateral body surface. These structures are described in detail based on SEM images. An identification key for Edotia species from South America is presented.