| 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. |
