Wagner & Van Damme, 2021
A new species of the thermosbaenacean genus Tethysbaena Wagner, 1994 (Crustacea: Peracarida: Thermosbaenacea) is described based on females from a freshwater cave lake and a brackish coastal well on Socotra Island (Yemen) as Tethysbaena dioscorida n. sp. It is the first representative of the Thermosbaenacea that is described from the Socotra Archipelago and the first member of the order known from an Indian Ocean island. The new species is the eighth known member of what is considered the “Tethysbaena relicta” species-group, which is known from Oman (four species), Somalia (one species), Israel (two species) and now Socotra Island (one species). The new species shows closest morphological affinities with T. barbatula Wagner, 2020 from Oman. We suggest that the speciation in this well-defined species-group is due to regressions of the Tethys Sea and the appearance of dry land since the Oligocene-Miocene boundary to the present time, forming major barriers and creating isolated populations of the ancestral species. Also the potential biocrisis in Socotra as a result of developmental activities during the last decades is mentioned, which may affect the subterranean faunas in particular in coastal areas, exemplified by the destruction of one of only two localities where the new species was found.
Tethysbaena dioscorida n. sp.
H. P. Wagner and K. Van Damme. 2021. A New Thermosbaenacean of the Genus Tethysbaena (Peracarida, Thermosbaenacea, Monodellidae) from Socotra Island, Yemen. Crustaceana. 94(4); 487–506. DOI: 10.1163/15685403-bja10115