How Many Walking Legs Do Crayfish Have?

10 legs make up a crayfish. The first two legs of a crayfish are pincers, or claws.

What Distinguishes Crayfish Walking Legs from Chelipeds?

The crayfish, often known as a crawfish or a crawdad, is mostly found in North America but can be found all over the world. Particularly, Kentucky, Louisiana, or the Mississippi Basin region are home to the majority of the 500 species of crayfish. The body structure and appearance of crayfish are similar to those of lobsters. There are four pairs of walking legs and one pair of chelipeds attached to the crayfish’s thorax. The limb with a claw, or chelae, is called a cheliped. Additionally, crayfish have smaller swimmerets under their tails.


The segmentation and flexibility of the abdomen are evident here. The crayfish’s appendages are joined to both the cephalothorax and the abdomen. The WALKING LEGS are the protrusions that connect to the thorax, and the illustration below shows how they are joined. SWIMMERETS are the tiny appendages that are joined to the abdominal segments. The crayfish in the photograph is female; males have bigger first swimmerets for gripping the female during copulation.

Observe the crayfish’s enormous claw. The crayfish utilizes this jointed claw, known as the CHELIPED, to defend itself and to snare prey.

The TELSON, which has fan-like fins that extend to either side, is a unique segment that makes up the very last segment of the crayfish. Crayfish can either utilize their urepods to propel themselves through the water or walk on the bottom of a lake or ocean. Since they move so quickly, crayfish can be surprisingly challenging to catch.


Crayfish typically have earthy hues of soft greens and browns. The cephalothorax (the combined head and thorax), which is completely enclosed by a single shell; the carapace, a six-segmented abdomen; and a five-sectioned, fan-shaped tail, the telson, make up the body’s three main components. The cephalothorax has five pairs of strong, armored, jointed periospods that are used for walking and digging. Large pincers (chelae), which are employed for defense and food gathering, are the end of the first pair of legs, referred to as the chelipeds. The antennae and antennules are two pairs of tiny antennae that function as specialized chemical detectors for foraging and mating. The antennae extend from the tip of the rostrum, a beak-like projection on the front of the head, on either side. Tactile or touch receptors are located on a third, longer set of antennae. With the exception of some cave dwellers who are essentially blind due to living in permanent darkness, two compound eyes provide exceptional eyesight. Two pairs of mandibles (the jaws) and three pairs of maxillipeds, which are small appendages that direct food to the mouth, are located beneath the rostrum. By swishing water through the banks of gills situated at the base of each pereiopod on the sides of the carapace in the gill chambers, the second pair of maxillipeds aids in gill ventilation. The 10 tiny appendages (the pleopods) on the strong, long, muscular abdomen facilitate swimming motions. The telson, which is found at the tip of the abdomen, is where the crayfish uses strong flips to quickly drive itself backward when it feels threatened.


According to their joined legs, crayfish are categorized as belonging to the phylum Arthropoda, class Crustacea, and order Decapoda (ten legs). Although the Rocky Mountains and western Great Plains have historically been mostly crayfish-free, they are present over the whole continent. Some crayfish dwell in damp areas away from bodies of water and even at the base of a slope where runoff from above gives their moisture. Crayfish are found in shallow waters that are both running and quiet (and yes, the BugLady is using a rather catholic definition of “bug” in order to include them under the “Bug” umbrella.”)

The cephalothorax is covered by a carapace (fused head and thorax). The rostrum is the protruding “snout” from the front of the carapace. The cephalothorax is decorated with antennae, stalked eyes, and five pairs of walking legs; inside it is a balance organ with gills and sensors made of sand grains. Small appendages can be found on the abdomen, which contains six segments and a “tail” resembling a flipper. Crayfish can move backward by quickly tucking or folding their jointed abdomen under them many times. They can also walk sideways. Crayfish move ahead by creeping. Crayfish are able to grow new appendages.

Crayfish (also known as crawfish or crawdads) are omnivores and frequent scavengers who eat both live and dead plants as well as aquatic insects, tiny fish, carrion, and snail species with thin, crushable shells. The front pair of legs’ biggest claws shred or crush its prey (When she was in an earlier instar, the Bug Lady used to angle for crayfish using raw bacon as bait, which both she and the crayfish thought was mighty tasty). Raccoons, otters, screech owls, numerous fish, and humans all consume crayfish, but people should prepare them thoroughly to prevent a lung fluke that crayfish in the eastern portion of their range play intermediate host to.

Crayfish are a significant component in aquatic ecosystems, according to the outstanding J. Reese Voshell, Jr. book A Guide to Common Freshwater Invertebrates of North America. The density of the aquatic plants, which affects the wellbeing and make-up of the allied animal group, may be influenced by their behaviors.

There are four pairs of walking legs on the crayfish.

How are crayfish walking legs different?

Which bodily component is the walking legs related to? The cephalothorax is where they are attached. Apart from the fact that some of the legs appear shorter since they are situated on the lower portion of the cephalothorax, we don’t detect any other significant distinctions in the legs. Pinchers are present on the first two sets of legs.

On a crayfish, where are the walking legs?

The crayfish’s pereiopods, or walking legs, are joined to the animal’s thorax. The crayfish’s walking legs serve both as their primary means of propulsion and as a means of searching rock crevices and fissures for potential food sources. Crayfish are shielded from predators by a tough exoskeleton that must be shed during molting as they get bigger. When a crayfish is attacked by a predator, it is normal for it to lose its walking legs despite this defense; nevertheless, the loss is temporary. Crayfish have the capacity to grow new limbs.

Crayfish do they have ten legs?

10 legs make up a crayfish. The first two legs of a crayfish are pincers, or claws. Pincers are used by crayfish to grab, crush, and cut food. Pincers are also employed for defense and digging.

What purpose do a crayfish’s walking legs serve?

Legs utilized for walking, acquiring food, and transferring water over the gills are known as “water walking legs.” Antennae are a long, thin anterior component needed for balance and touch as well as food flavor. A small, narrow anterior device called an antenna is utilized to taste food.

What is the name for crayfish legs?

The pincer, also known as the chelae, is the terminal claw on the front pair of legs that protrudes from the carapace. Pleopods are the crayfish’s first five abdominal segments’ appendages. The first pair becomes gonopods in males.

Crayfish can they move on land?

Freshwater species must frequently transcend terrestrial barriers to disperse between isolated waterbodies, and many freshwater animals that are unable to fly must rely on conveyance via flooding events, other animals, or manmade activities. On the other hand, decapods like crayfish can travel to nearby waterbodies by walking on land, a trait that has aided the spread of invasive species. The management of invasive crayfish may heavily rely on overland travel, however it is unclear how much various species engage in terrestrial emigration. Here, the terrestrial emigration propensities of two alien crayfish species—the red swamp (Procambarus clarkii) and signal (Pacifastacus leniusculus) crayfish—in Great Britain were directly compared. Both species were observed to migrate from the water, and there was no discernible difference in either species’ tendency to migrate to land, indicating that there is a chance that both of these species may go overland and spread to new environments. This study demonstrates that terrestrial emigration is a crucial behavioral characteristic to take into account for limiting crayfish escape from aquaculture and the spread of invasive species.

What components make into a crayfish?

Whew! Let’s go through what we learned about crayfish again. Crayfish are arthropods that can be found in many watery habitats. They typically reach a height of 6 inches, have a lifespan of 2 to 3 years, and are known as “crawfish” or “craw-dads” in the southern United States. They are secretive, rock-dwelling nocturnal omnivores who hunt at night.

The cephalothorax, which is the combined head and thorax of crayfish, and the abdomen are its two body segments. The eyes, antennae, and antennules are located in the cephalothorax, which is shielded by a carapace. The mandibles, two pairs of maxillae, and the maxillipeds are also present. Internally, the cephalothorax houses important organs like the heart, liver, and gills past the head area. The walking legs and chelipeds are located externally.

The crayfish’s swimmerets, uropods, and telson are all found in the abdomen. Additionally, the telson and uropods work together to form the tail fan that allows for swimming backwards.

What are the top 5 crayfish facts?

  • Crayfish can consume cat food and hot dogs.
  • A crayfish may be sandy yellow, pink, red, dark brown, or blue in color.
  • The crayfish is a relative of the lobster.
  • All continents, save Africa and Antarctica, are home to crayfish.
  • In North America, crayfish are found in 200 different species.
  • Crayfish engage in territorial conflict

Crayfish have teeth, right?

Crabs and lobsters have teeth, but they are in their guts. These are utilized to break down their food, but strangely enough, ghost crabs also use them to scare off predators by generating noise.

Unbelievably, the stomachs of lobsters and other crustaceans like crabs and crayfish have teeth. Their stomachs may actually crush food as a first step in the digesting process because to the rhythmic movements of the three huge teeth that make up the “gastric mill” mechanism.

In addition, ghost crabs use their “stomach teeth” for other purposes. It may sound unusual, but these crabs actually make noises that scare off predators using the stomach mill. In essence, the ghost crabs can mimic the sounds made by rubbing the ridges on their claws together by grinding the teeth in their stomach, much like they would do to break up food. When the crabs feel threatened, they frequently make this noise, which is supposed to serve as a warning sign to scare off potential predators out of dread of being clawed. Additionally, the sound can be utilized to convey details about a crab’s size, ferocity, and intent.

Ghost crabs have a “double-edged sword” when it comes to combat since they can make this sound with both their claws and their stomachs. They can still grind out warning signs with their “stomach teeth” while using their claws for combat.

At McGill University, Caitlin Bard is completing her Bachelor of Science with a focus in neuroscience.