Spatial and temporal variability in the distribution and diet of the gudgeon (Eleotridae: Hypseleotris spp.) in a subtropical Australian reservoir

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.The diurnal distribution and diet of Hypseleotris spp. was examined over a 14-month period in Maroon Dam, a productive subtropical reservoir in south-east Queensland, Australia. Three distinct size classes of Hypseleotris were observed. The smallest (20 mm SL) of adult Hypseleotris remains in the near-shore littoral throughout seasonal and diurnal cycles and has a more eclectic diet than the other two size classes (zooplankton 28.8%, macro-invertebrate 28.9%, other 42.3%). Spatial and temporal differences in the distribution and diet of these three size class groups are discussed with reference to the abundance and availability of suitable prey, intraspecific competitive exclusion, predator avoidance and water quality.