- crustaceans - an arthropod of the large, mainly aquatic group Crustacea, such as a crab, lobster, shrimp, or barnacle.
- endangered- put someone or something at risk or in danger.
- esophagus- the part of the alimentary canal that connects the throat to the stomach; the gullet. In humans and other vertebrates it is a muscular tube lined with mucous membrane.
- krill- Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name krill comes from the Norwegian word krill, meaning "small fry of fish", which is also often attributed to species of fish.
- mammals -a warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, the secretion of milk by females for the nourishment of the young, and (typically) the birth of live young.