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Kidadl Team

AUGUST 06, 2021

Crayfish: 21 Facts You Won't Believe!

Crayfish facts such as they prefer calcium-rich waters are interesting.

Crayfish are found in both the Northern Hemisphere and Southern Hemisphere. In particular, they are found in North America, Europe, Australia, and Asia. Crayfish are crustaceans that are found almost exclusively in freshwaters such as rivers and streams. However, the diversity of crayfish is less in the Southern Hemisphere. They have many names and crayfish vs crawfish is a popular debate.

There are many species of crayfish. They have a large genus distributed over different parts of the world. Resembling a smaller version of lobsters, crayfish belong to Astacidae, Cambaridae, and Parastacidae families. Of these, the family Cambaridae is the largest. The body of a crayfish has two main sections, the cephalothorax and the abdomen. The average crayfish will be 6-17 in (15.2-43.1 cm) long and may weigh 0.6-0.9 lb (1.5-2 kg). Like lobsters, the body of the crayfish has 19 segments in its body. Crayfish are also known as crawfish, crawdads, and some other names.

Crayfish feed on small fish, plants, snails, earthworms. In the food chain, it is consumed by fish, birds (such as herons), raccoons, and other animals. Crayfish are also consumed widely by people in various parts of the world. Some species of crayfish can be as small as 1 in (2.5 cm) and as large as 15.7 in (40 cm). A crayfish weighing 7.7 lb (3.5 kg) is supposed to be large but it is not uncommon.  Crayfish are covered with a tough layer of exoskeleton which they molt from time to time. This is necessary for the crayfish to grow. Crayfish molt up to 10 times during their first year.

If you like this article, why not check out more facts on blue crabs and clownfish!

Crayfish Interesting Facts

What type of animal are crayfish?

One of the most curious crayfish facts is that they resemble small lobsters. Crayfish are not fish but shellfish. They belong to crustaceans that have a strong protective layer called the exoskeleton. Crayfish are mostly found in freshwaters such as rivers or streams, but saltwater crayfish also exist. Many American species of crawdad are a popular food.  

What class of animal do crayfish belong to?

Crayfish belong to the Malacostraca class of animals. These animals have a wide diversity of body forms. For example, they possess mouthparts, antennules, and antennae. Catfishes are often the largest invertebrates in the habitats where they are found. Crayfish are a freshwater organism of Arthropoda phylum and the subphylum Crustacea.

How many crayfish are there in the world?

There are over 600 crayfish species in the world. While crayfish species are found in many parts of the world, they are chiefly located in the Southeastern United States and Southern Australia. Over 250 freshwater crayfish species are found in North America. In Southern Louisiana, the most famous red swamp crawfish is farmed. Another famous North American species is the golden crayfish found in Ozark streams. White river crawfish which resemble the red swamp crawfish is another United States crayfish. These two species are widely used for food. The blue crayfish are found in Florida. Together, these three species are very popular in the US.

Where do crayfish live?

Crayfish live in the darker parts of the water such as under the rocks, logs, and shallow holes and tunnels they dig in their habitat. Freshwater crayfish are found in wetlands, swamps, rivers, streams, lakes, canals, ponds, and ditches.

What is a crayfish's habitat?

Crayfish live in shallow freshwaters such as rivers or streams and are sensitive to light. It prefers to be active during the night and in a darker environment. So, they make their homes under the rock, logs, and shallow holes and tunnels that it digs.

Who do crayfish live with?

Crayfish are bottom-dwelling freshwater creatures that feed on insects, plants, and small fishes. If you keep it in an aquarium as a pet, you have to choose mates such as fish carefully. Crayfish may not be able to kill a fish immediately but they can attack repeatedly and harass small fish.  

How long do crayfish live?

Crayfish live for 20-30 years in the wild. In captivity such as an aquarium, they can live for two to three years. Some species can live longer in captivity. Crayfish grow to their adult size in about four years.

How do they reproduce?

The reproduction of crawfish is sexual. The sexual maturity of crawfish comes at the age of five to eight years.

The breeding season for crawfish is early spring. Males have to fight to assert their right to copulate. In the fight, they often lose walking legs or claws. Female gets pregnant when they have molted as this allows the male to conjugate and deposit sperm packets in the female’s lyceum. Female crawfish carry the fertilized eggs in their bodies for up to six weeks. The developing eggs get transferred outside the body and remain glued to the female’s tail.

What is their conservation status?

Crawfish are regarded as Endangered. As per a report, one-fifth of North American crawfish species, which constitute one-third of the crawfish species worldwide, are threatened with extinction.

Crayfish Fun facts

What do crayfish look like?

Crayfish are very old, around 150 years old.

Crayfishes look like small lobsters, with a front pair of solid squeezing paws, a reinforced body, and an expansive tail. Crayfish are found in a range of colors. They have stalked eyes and a sharp snout. The forward portion of the body is unbending. However, the back part, the mid-region or tail, has mobile sections. In the head district, two sets of radio wires and little eyes help the crawfish in detecting its environmental factors.

How cute are they?

Crayfish are extremely cute because of their unique body features. Their fragmented bodies sport different colors from green, red to yellow. The head has a sharp mouth and composed eyes that move on stems. The physical cover is skinny but hard. In the pet business, crawfish have a special appeal.

How do they communicate?

This is odd but true, lobsters and crayfish communicate by sending each other urine jets. It looks gross, but it's kind of neat. A lot of animals generate chemical signals for communication. These signals, or pheromones, can transmit information on reproductive readiness or dominance. In the head district, two sets of radio wires and little eyes help the crawfish in detecting its environmental factors.

How big are crayfish?

Most grown-up crayfish are about 3 in (7.6 cm) in length. Among the smallest are the 1 in (2.5 cm) long Cambarellus diminutions of the southeastern United States. Among the biggest is the Astacopsis goal of Tasmania, which may arrive at 15.7 in (40 cm) long and weigh about 7.7 lb (3.5 kg).

How fast can crayfish move?

Crayfish can make rapid movements, thanks to the four pairs of walking legs they have. These legs help them move faster at the bottom substrates of the water where they mostly live. They are not great swimmers yet they make quick movements in the water by the thrusts of their tail and abdominal movements. They can float forward and backward but can’t walk in the reverse direction.  

How much do crayfish weigh?

Usually, crayfish will weigh between 3.3-5.5 lb (1.5-2.5 kg). However, both smaller and larger varieties of crawfish can be found. For example, red crayfish develop to around 17.7-19.6 in (45-50 cm) in length and weigh around 4.4-6.6 lb (2-3 kg). Packhorse crawfish grow up to 23.6 in (60 cm) and can weigh 33 lb (15 kg).

What are the male and female names of the species?

Male and female crayfish are called male crayfish and female crayfish respectively.

What would you call a baby crayfish?

Baby crayfish can be called langostino. In reality, langostino is Spanish for 'little lobster'.

What do they eat?

Crayfish can eat both plants and creatures, which makes them omnivores. They feed on new vegetation, alongside living and non-living spineless creatures like bugs, worms, and snails. Crawfish can also feed on fish and other crayfish, live and dead, vegetables, and water plants. The majority of the vegetables they ingest in nature are aquatic plants.

Are they dangerous?

Crayfish is used as food in many parts of the world. This has led to the transfer of popular species from one part to the other parts of the world. Red swamp crayfish or signal crayfish are examples of this kind of migration of crayfish. The new species create ecological strife by threatening the local species. They also carry deadly parasites such as rat lungworms and have been blamed for causing crayfish plague.

Would they make a good pet?

Crayfish, otherwise called crawfish, crawdads, and mudbugs, are freshwater crustaceans that can undoubtedly be kept in a home aquarium. Crayfish can make for superb pets. They can be seen moving up and down the slopes and hills. They burrow and tuck away among shadowy shakes and plants. They also make tunnels in the rock at the lower part of their tanks.

Crayfish are easily maintained and often interact with their owners. While crayfish are certainly not safe for a community aquarium, it is good to have a reservoir dedicated to crayfish. Most crawfish need cold water, but some need tropical temperatures to thrive.

Did you know...

The very first thing you learn about crayfish is not to eat the right-tailed crayfish. It is said that the right-tailed crayfish were dead before boiling and are, therefore, not edible. This little tip has been handed down from generation to generation, and it's one of the most popular myths about crayfish.

Crayfish and humans

Just a little part of the crawfish’s body is consumable. In most dishes, like soups and bisques, just the tail parcel is served.

However, people get infected by eating raw or undercooked crawfish or freshwater crabs that harbor parasites. This usually affects the lungs, but may affect other organs, including the brain and skin.

What makes crayfish unique?

It has a unique muscular structure that allows crayfish to swim backward rapidly in the water. They have two large claws, or claws that stretch in front of the thorax. Their claws can re-grow if they are lost and play three main roles: feeding, mating, and fighting.

Its eyesight also makes it unique. They have great visual perception and they can move their eyes autonomously from each other and without moving their body.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! For more relatable content, check out these glowlight tetra facts and mantis shrimp facts for kids.

You can even occupy yourself at home by coloring in one of our free printable Crayfish coloring pages.

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