Der Zwergfadenfisch vermag über der Wasseroberfläche befindliche Beute durch Spucken zu erjagen. Dabei wird durch Zusammenpressen der Kiemendeckel das vorher angesogene Wasser in einer Serie tropfenweise abgegeben. Mit Zeitdehnung.

The film shows a male Colisa lalia in the act of spitting water. When the food (lightly attached to a small wooden stick which is held a few centimetres above the surface of the water) appears the fish swims diagonally upwards towards the surface in a way peculiar to it. Then it spits a series of water drops towards the food. The water it spits is sucked in through caudal and ventral, and is forced out through the mouth by the pressure of the opercula. The angle made by the body of the fish and the direction of the spit is a constant 158 ° (± 5 °). When the fish is in the process of spitting a change in the position of its body can often be observed, and this increases the certainty of its reaching the food. Should it miss its target in most cases it spits a new series of water drops towards the food. It often also leaps towards the food.