The behaviour of recently hatched Tobago glass frog tadpoles

Egg clutches of the Tobago glass frog Hyalinobatrachium orientale tobagoense were collected from streams around the north-east of Tobago and hatched into tanks of native stream water. Previously unreported behaviour of newly hatched tadpoles was observed. Observations were made through a series of tests for substrate preference (gravel, rocks or leaves), shelter or open water preference, and surfacing behaviour under different depths and turbulence levels. Tests found that tadpoles showed a preference for stream substrates over plastic tank floor, with the highest percentage of tadpoles found in gravel. Tadpoles preferred sheltered areas of the tank, and surfaced significantly less when water was turbulent, with depth having no significant effect on surfacing behaviour.