Microhabitat selection by tadpoles of <Emphasis Type="Italic">Buergeria japonica</Emphasis> inhabiting the coastal area

Microhabitat selection is particularly important to increase the survival rate and reproductive success of animals inhabiting heterogeneous environments. I investigated microhabitat selection of Buergeria japonica tadpoles inhabiting the stream in a coastal area to reveal how animals select their appropriate habitat under heterogeneous and unstable environments on the subtropical Okinawa Island of Japan. Tadpoles are sensitive to subtle environmental changes, and the mouths of streams in coastal areas that have intense environmental fluctuations such as desiccation and sudden changes in current velocity would be risky habitat for tadpoles. Tadpoles of B. japonica can inhabit both lotic and lentic systems. Field observations showed that, among six physical factors (water depth, water temperature, salinity, pH, current velocity, and substrate), current velocity and water temperature were key factors in microhabitat selection by tadpoles. It is likely that tadpoles stay at low current velocity sites to reduce the probability of being washed out to the sea by a sudden squall and that selection of warmer sites would accelerate development of tadpoles so as to escape the heterogeneous aquatic habitat sooner.