Abstract
Recent surveys revealed a high biodiversity of freshwater shrimps, Atyidae De Haan, 1849 in northern Vietnam. Here, we describe four new species of the genus Caridina, C.ngocson sp. nov., C.xuanlien sp. nov., C.tanson sp. nov., and C.tamkim sp. nov. The new species can be distinguished from their congeners by distinct characteristics of the rostrum, stylocerite, first and second pereiopods, male first and second pleopods, and uropodal diaeresis. Molecular phylogenetic analyses of the mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA (16S) genes support the distinctness of the new species from all other species examined.