parasite An organism that gets benefits from another species, called a host, but doesn’t provide that host any benefits. Classic examples of parasites include ticks, fleas and tapeworms.
predator (adjective: predatory) A creature that preys on other animals for most or all of its food.
sea An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.
sea anemone An animal that usually lives on the seafloor and reefs. Although the young larvae disperse through the water, they eventually settle and permanently anchor themselves to a solid structure. They have a tube like structure and resemble a soft, flower. But what appear to be petals are actually stinging tentacles that ring their mouths.
species A group of similar organisms capable of producing offspring that can survive and reproduce.
symbiosis (Adj. symbiotic) A relationship between two species that live in close contact. A species that lives this way, offering substantial help to the other species, is sometimes called a symbiont.
venom A poisonous secretion of an animal, such as a snake, spider or scorpion, usually transmitted by a bite or sting.