Anni taught elementary school for eight years and is currently teaching college. She received her Ed.D. in Curriculum and Instruction.
Nocturnal, Freshwater Animals
Can you imagine being awake during the day and asleep during the day? Well, that is how crayfish live. They are nocturnal animals, which means just that - they are awake at night and asleep during the day. These yellow, green, or dark brown animals, often called 'crawdads' or 'crawfish', live in bodies of freshwater like streams and rivers. They have a sharp snout and moveable eyes on long moveable branches that extend from their head.
Crayfish in North America tend to be about 1-6 inches long, though there are some species in other parts of the world that are two feet long and weigh 10 pounds!
What Do They Look Like?
Crayfish are part of the crustacean family. Crustaceans have a body that is made up of three separate segments, including a head, thorax, and midsection. They also have a hard exoskeleton, or a hard shell that provides support and protection. While the exoskeleton provides protection, it also does not let the crayfish grow larger. This is like growing out of a pair of pants and needing new pants that fit. So, crayfish get a new protective covering by shedding their old one and growing a new one through a process called molting. However, when they are in the process of growing a new exoskeleton, they have very limited protection from predators.
Living and Food
Crayfish live in fresh bodies of water in many parts of the world, including North America, Europe, New Zealand, and East Asia. Crayfish are omnivores, which means they eat both plants and animals. They eat fish, shrimp, water plants, worms, insects, snails, plankton, and will even eat dead plants and animals. They eat by using their pincers - large claws that are specialized for defending themselves and cutting their food.
While crayfish eat specific things, other animals eat crayfish. Actually, people like to eat crayfish. Crayfish meat is usually eaten with your fingers and tastes sweet.
Just like a starfish, a crayfish can also grow back its legs if they are lost in a fight with a predator or for any other reason. This is called regeneration.
The life cycle of a crayfish begins when a female lays nearly 100 eggs. The eggs remain attached to her abdomen and kept in place with small limbs called swimmerets for 2-20 weeks.
At the end of that period baby crayfish start coming out of the eggs. For the first couple weeks the baby crayfish stay with their mother for protection because other animals eat them. As the crayfish grows it will continue the cycle of molting. After only being alive for about 4 months the crayfish reaches full adult size. While most crayfish live about 2-4 years, some species can live up to 20 years.
Crayfish, also known as crawdads or crawfish, are nocturnal freshwater animals that are part of the crustacean family. They are protected by an exoskeleton that needs to be molted frequently in order for the crayfish to grow. Most live about 2-4 years and enjoy eating both plants and animals. Crayfish can be yellow, green, or dark brown.
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