Draft paper - Fish biodiversity within the rivers of eastern African rivers is typically not well documented. This lack of knowledge can hinder effective designation of habitats and species requiring conservation interventions. This study investigates mitochondrial oxidase subunit I (COI) sequences to barcode sand catlets (Zaireichthys sp.) samples from Tanzania, Malawi and Zambia. We used two different methods of species delineation, the General Mixed Yule Coalescent (GMYC) approach and the multi-rate Poisson Tree Process (mPTP), to resolve the presence of at least eight potential species, of which three are not previously recognised on DNA barcode databases, and potentially represent new species. Our results add to a growing literature suggestive of cryptic fish diversity in Eastern Africa, and highlighted the need for further research on stream fishes in that region.