Sea snails, chitons and sea urchins are examples of herbivores that graze on algae, seaweeds and other plants. Others scavenge, and some are omnivorous, feeding on whatever food is available. Many carnivorous invertebrates rely on camouflage to lure their prey. Others scavenge leftovers from meals of other animals. Some invertebrates are parasites that live in or on other animals and derive nourishment from their host species.
Some invertebrates live symbiotically with other organisms.
Another example is the association between sea anemones and clownfishes. The clownfishes gain protection while the sea anemones get bits of dropped food. Invertebrates have many different reproductive strategies. Squids and octopuses reproduce sexually. Other invertebrates use the broadcast method where both male and female gametes are released into the water in enormous quantities and left to unite by chance.