Molecular phylogenetic position of Minamitalitrus zoltani elucidates a further troglobisation pattern in cave-dwelling terrestrial amphipods (Crustacea: Talitridae)

Talitrids are a highly diverse group of amphipod crustaceans that have colonized various terrestrial habitats. Three genera successfully adapted to cave habitats on islands in the Pacific and Atlantic Oceans. However, evolutionary origin troglobitic talitrids has remained unknown. We estimate phylogenetic position Minamitalitrus zoltani, which inhabits limestone caves Minamidaito Island Northwestern Pacific, basis traditional multi-locus dataset. For analyzed talitrids, we also reconstruct ancestral states maxilliped palp male gnathopod 2. Our results indicate zoltani is sister epigean Nipponorchestia curvatus with deep divergence. coastal Japan, but not indigenous Island. A previous study estimated species had invaded subterranean multiple times, provide new insight into troglobisation history talitrids. recover secondary shifts character 2 within lineage composed its phylogenetically close genera. findings highlight need for genus-level reclassification these genera; split two genera, establishing genus nudiramus.