Diversity of freshwater fishes from eastern Sabah: Annotated checklist forDanum Valley and a consideration of inter- and intra-catchment variability

Intensive collection of freshwater fishes over a period of two years and a review of old records revealed that a total of 47 species in 12 families ar e currently known from the catchment of the upper Segama River near Danum V alley Field Centre, eastern Sabah, an increase of 10 species over previous checklists. Notes on occurrence, ecology and taxonomy are given. Additional collections were made from headwater streams in the catchment of the Kuamu t River and from the lower Segama river to assess the contribution of inter - and intra-catchment variability to total biodiversity of the region. An a dditional 13 species in six families were found during a week-long survey o f the lower Segama area, while an additional 5 species and two families wer e collected from headwaters of the Kuamut River in five collections over 18 months. Quantitiative analysis of data from hillstreams from the Segama an d Kuamut rivers showed substantial differences in fish communities over sho rt geographical distances, whereas similar qualitative differences were fou nd longitudinally along the Segama Full assessment of biodiversity must tak e such patterns into account.