The producer of the ponds ecosystem is algae. It gets its energy from the sun and is consumed by the herbivores. Producers produce energy with out taking it from another animal.
One of the herbivores of the ecosystem are minnows they feed on the algae in the pond. Herbivores only feed on plant life.
The catfish is the carnivore of the ecosystem and feed on other fish. Carnivores are meat eaters.
The omnivore of the ecosystem are turtles because they eat algae and fish such as minnows. Omnivores are animals that eat both other animals and plant life.
The worm in the ecosystem decomposes dead animals. Decomposing animals break up any dead biotic life in to small matter.