Taxonomic Study Of Four Species Of Freshwater Amphipoda(Crustacea: Amphipoda)

The present dissertation deals with the taxonomic study of four species of freshwater Amphipoda(Crustacea: Amphipoda: Senticaudata).Four parts are included.The first part deals with general information of the freshwater Amphipoda,the current research state in China and the other countries,morphology and biological significances.This paper reported the result of a detailed study of 4 species,which all belonging to suborder Senticaudata.Each of the four species is given to descriptions,diagnosis,illustrations and geography data.Gammarus simplex Hou,2017 collected from Altay,Xinjiang.Gammarus glaber Hou,2017 collected from Haidong City,Qinghai Province.The genus Gammarus is one of the largest genera of freshwater amphipods,containing more than 200 described species.This genus has a broad range covering the Eurasia and across the Atlantic to North America.It has been suggested that Gammarus originated from the ancient Tethys,then diversified in the Eurasia driven by the tectonic uplift and Tethyan regression.Gammarus species are geologically defined,and most species are restricted to local regions.In China,more than 70 species of Gammarus have been recorded;however,most of them are collected from South China.A subterranean species of Pseudocrangonyx elegantulus Hou,2017,is described from caves of Wulongdong National Forest Park in Henan Province.The genus Pseudocrangonyx was established by Akatsuka & Komai in 1922,including 21 described species that are widely distributed in subterranean freshwaters or springs of Japan,the Korean Peninsula,eastern China,and the Far East of Russia.The genus exhibits typical subterranean adaptive morphology in the loss of eyes and pigmentation,elongated appendages,and vestigialization of dorsal armature on urosomites.Victoriopisa multiartus Hou,2016 collected from Qi'ao Island is the 10 th species of genus Victoriopisa and up to now,only one species distributed in China.The genus Victoriopisa Karaman & Barnard,1979 belongs to Eriopisa group,which is widespread in shallow interstitial and benthic habitats of tropical and subtropical seas.