Sinking velocities of the various feed types were measured with a digital stop-watch over a distance of 100 cm between two points at the 10 and 110 cm marks after pellets were dropped from a height of 5 cm above the water surface. To ensure accurate depth recordings, a large-tipped marker was used to mark the 10 and 110 cm depths around the cylinder. The 10 cm marking from the top of the tube was to allow feed pellets to reach terminal or constant velocity before timing. Single pellets of around the same lengths (1 cm) were randomly selected for sinking velocity measurements and sinking velocities were recorded as cm s−1. Thirty (30) pellets were randomly chosen for each diet for the test and feed pellets that came into contact with the tube wall during a fall were excluded.