Add butter/olive oil combination. Add the fillets, without crowding. Increase heat to high and saute, shaking the pan from time to time, until the bottom of the fish is nicely browned, about 3 minutes. Turn and brown the other side. Remove fish to a plate and keep warm in the oven. Repeat with remaining fillets.
Copepods are considered to be primary consumers. They form an important link in the food chain. Their diet consists of small plant plankton.
Third-level consumers are any organisms big enough to obtain energy by feeding off lower-level consumers. These are also called tertiary consumers. For example, in a forest ecosystem, snakes eat toads. Heron and large fish, such as bass and walleye, consume smaller fish, frogs and crayfish. Some ecosystems have four or more levels of consumers. Owls, high-level forest predators, go after third level consumers such as snakes and other smaller animals.