A new species of Thermosphaeroma Cole & Bane, 1978 (Isopoda: Sphaeromatidae) from a thermo-mineral spring in northern Jalisco (Chihuahuan Desert, Mexico), with an assessment of the conservation status of the species of Thermosphaeroma

Abstract

We describe a new species of Thermosphaeroma Cole & Bane, 1978 discovered in a thermo-mineral spring in the Mexican state of Jalisco, within the Mexican Plateau subprovince of the Chihuahuan Desert. This species represents the ninth known in the genus and the eighth identified in Mexico to date. Alongside morphological characteristics, the distinctiveness of the new taxon is corroborated by a molecular phylogeny of the genus based on mitochondrial cytochrome c oxidase DNA sequences. Diagnostic features of the new species include elongated rami of the uropods, each extending at least to the distal margin of the pleotelson, and marked sexual dimorphism in uropods, with the female endopod being significantly longer than that of the male. We surveyed all known species localities to evaluate the conservation status of its populations. We unfortunately document the loss of four species presumed extinct due to excessive groundwater extraction resulting from declining aquifer levels and anthropogenic alterations to their habitats.