Definition: A tiny sea creature that belongs to a group of small crustaceans, known for having a flattened body and lacking a hard outer shell.

Example: The amphipod scuttled across the sandy beach, searching for food.

Definition: A mythical creature that looks like a serpent and has a head at both ends of its body, allowing it to move in either direction.

Example: In ancient stories, the amphisbaena was said to be able to bite its own tail.

Definition: A specific mating position in which a male frog or toad holds onto a female during reproduction, allowing for the fertilization of eggs as they are released into the water.

Example: During amplexus, the male frog clings to the female to ensure the eggs are fertilized as they are laid.

Definition: A type of freshwater fish that belongs to the family Anabantidae, found in Africa and Southeast Asia, which includes species like the gourami and climbing perch.

Example: The anabas is known for its ability to breathe air and move across land for short distances.

Definition: A type of fish that has a unique eye structure, allowing it to see both above and to the sides at the same time, making it appear to have four eyes.

Example: The anableps is known for its remarkable ability to see both above and below the water's surface.

Definition: A large, nonvenomous snake found in tropical South America that kills its prey by wrapping around it and suffocating it. These snakes can grow very long, sometimes reaching lengths of over 30 feet.

Example: The anaconda is known for its impressive size and strength, making it one of the largest snakes in the world.

Definition: Referring to fish that travel from the ocean to freshwater rivers to reproduce.

Example: Salmon are anadromous fish that return to their birthplace to spawn.

Definition: A group of birds that includes various types of ducks, typically found in freshwater environments.

Example: The anas are often seen swimming in the lake during the summer months.

Definition: Describing a state in which an animal is not in heat or not experiencing the reproductive cycle.

Example: The female dog was anestrous, meaning she was not in heat at that time.

Definition: A time when female mammals are not sexually active, occurring between two cycles of sexual activity.

Example: During anestrus, the female does not show signs of being in heat.