Fauna Ikan Siluriformes Dari Sungai Serayu, Banjaran, Dan Tajum Di Kabupaten Banyumas

__________________________________________________________________________________________ Most of the order Siluriformes live in river, this the fish has various morphology diversities. This study was conducted to determine the morphology variations, species richness, and abundance of the order Siluriformes in Serayu, Banjaran, and Tajum River in Banyumas. The research method used explorative survey while the sample drawing used random sampling method, then the data were analyzed descriptively. The species of Siluriformes that were collected from three rivers belong to family Bagridae (seven species); Clariidae (one species), and Sisoridae (one species). The morphology characters that can be used to differentiate the Siluriformes member are the presence of adipose fin; the ratio of the length of adipose and anal fin; the shape and size of burble; and the shape of caudal fin. Generally, the existence os Mystus nigriceps is more abundant than six other species