Metahadzia uncispina, a new amphipod from phreatic groundwaters of the Guadalquivir River basin of southern Spain

Metahadzia uncispina n. sp. is described, being the second species of the genus on the Iberian Peninsula. The new species, well characterized by the transformation of the apical spine on the endopodite of the male uropod 2, is undoubtedly closely related with M. tavaresi (Mateus & Mateus, 1972) from the south of Portugal. Comments are made about recent emendations of the original concept of the genus Metahadzia Stock, 1977.