King rail
This rail forages in shallow water near cover and eats mainly aquatic insects and crustaceans. It forages by probing the mud while moving around in shallow water.
Detritus
There is an extremely large number of detritus feeders in water. After all, a large quantity of material is carried in by water currents. Even if an organism stays in a fixed position, as long as it has a system for filtering water, it will be able to obtain enough food to get by. Many rooted organisms survive in this way, using developed gills or tentacles to filter the water to take in food, a process known as filter feeding.