Motion of the gnathobases moves food anteriorly in the food groove. The motion of the spiny gnathobases can be seen in living specimens viewed from the ventral surface. The large flat exopods are primarily responsible for stirring sediments. Fine silt particles and water escape laterally but coarse particles, including food, remain in the groove. Here they are torn into small pieces by the sharp bladelike endopods and moved anteriorly to the mandibles and mouth by the gnathobases.
Particulate food includes small insect larvae, oligochaete worms, and tadpoles.
Notostracans may also engage in suspension feeding while swimming. For this they use the setae of the endites. Feeding is easily observed in living notostracans. To observe predation simply place a tadpole shrimp in a small dish with some brine shrimp smaller than the tadpole. Small oligochaetes such as Tubifex can also be used.