Two new species of the genus Trichorhina Budde-Lund, 1908 (Crustacea: Isopoda: Platyarthridae) from the Ibero-Balearic region

Two new species of Trichorhina Budde-Lund, 1908, the most diverse genus of the family Platyarthridae, are described from the Ibero-Balearic region: T. guadianensis sp. nov. (Portugal) and T. malacitana sp. nov. (Spain). The two species are distinguished by differences in dorsal integument texture, scale-setae arrangement, shape of the telson, posterior pereonites margins, and male pleopod 1. Trichorhina guadianensis sp. nov. is characterised by a smooth dorsal integument with longitudinal lines of fan-shaped scale-setae of different sizes, rounded posterior margins of pereonites 1–4, triangular telson, and a heart-shaped male pleopod 1 exopod. Trichorhina malacitana sp. nov. is characterised by the absence of pigmentation and eyes, transverse lines of fan-shaped scale-setae, triangular telson, and an oval male pleopod 1 exopod. The position of the noduli laterales on the pereonites provides additional diagnostic characters for the identification of all species of the genus. A revised dichotomous key for all species of Trichorhina in the Ibero-Balearic region is provided.