What do marine invertebrates eat?

Since there is a wide array of marine invertebrates there are carnivores, herbivores, and omnivores in the mix.  Many marine invertebrates such as marine snails eat algae and seaweed.  Others, such as corals and sponges, are filter feeders, eating plankton and small fish that are floating in the water.  Many marine invertebrates are carnivores and eat fish, crustaceans, and other marine invertebrates.