“Based on feeding habits, researchers broadly classify ray-finned fishes as herbivores, carnivores, omnivores, zooplanktivores and detrivores.”
“The detrivores and decomposers are not always represented in these pyramids but they play an essential role in the cycle of material.”
“Some authors, for example, combine the subclasses Palaeotaxodonta and Cryptodonta into a single group of primitive detrivores with protobranch gills.”