LAUSR

Abstract Seven new species of the genus Gammarus are described and illustrated from southern China. The new species Gammarus vallecula Hou & Li, sp. n., G. qinling Hou & Li, sp. n., G. zhigangi Hou & Li, sp. n. and G. jidutanxian Hou & Li, sp. n. are characterized by inner ramus of uropod III half the length of outer ramus. Gammarus longdong Hou & Li, sp. n. is characterized by inner ramus of uropod III 0.9 times as long as outer ramus. Gammarus mosuo Hou & Li, sp. n. is characterized by pereopods V–VII with long setae on anterior margins and both rami of uropod III armed with simple setae. Gammarus caecigenus Hou & Li, sp. n. can be distinguished from other species by eyes absent. DNA barcodes of the new species are documented as proof of molecular differences between species. A key to the new species and a map of their distributions are provided.