Some Antarctic fish arrange their nests into odd shapes

Antarctica: A continent mostly covered in ice, which sits in the southernmost part of the world.

aquatic: An adjective that refers to water.

biology: The study of living things. The scientists who study them are known as biologists.

egg: A reproductive cell that contains half of the genetic information necessary to form a complete organism. In humans and in many other animals, ovaries produce eggs. When an egg fuses with a sperm, they combine to produce a new cell, called a zygote. This is the first step in the development of a new organism.”

footage: (in movies and videos) A term for the uncut or unprocessed motion pictures or video imagery taken by a camera. It takes its name from the fact that it took several feet of film to capture a few seconds of motion-picture photography.

imprint: (in animal behavior) A term for process by which a young animal comes to view some other animal (or person or thing) as its parent or trusted caregiver.

marine: Having to do with the ocean world or environment.

marine biologist: A scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales.

predator: (adjective: predatory) A creature that preys on other animals for most or all of its food.

risk: The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)

robot: A machine that can sense its environment, process information and respond with specific actions. Some robots can act without any human input, while others are guided by a human.

sea: An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.

species: A group of similar organisms capable of producing offspring that can survive and reproduce.