The Unique Noises and Sounds Made by Crayfish

Crayfish also known as crawfish or crawdads are fascinating freshwater crustaceans that inhabit rivers, lakes, and streams around the world. These creatures are known for their large front claws and armored exoskeletons. But did you know that crayfish also have the ability to produce sounds both in and out of the water? Here’s an overview of the different noises and sounds made by these intriguing animals.

Pulsing Sounds Underwater

While crayfish don’t have vocal cords, they can generate clicking and pulsing sounds underwater. These noises are produced by a thin appendage that constantly draws water over the gills. As the water and air pass through this appendage, it vibrates rapidly, creating a pulsing or clicking noise

This sound is known as a “pulse train” and it resembles a series of Morse code clicks. Scientists believe crayfish produce these pulses as a way to communicate with each other while submerged. The pulses likely convey information related to mating, warnings about predators, and other key messages

By listening closely, you may be able to hear the faint clicks of crayfish pulse trains underwater near river banks or lake shores. Keep your ears peeled when you’re near freshwater crayfish habitats.

Stridulation Sounds on Land

When crayfish are out of the water, they make different sounds by rubbing various body parts together. This is known as stridulation. Most species stridulate using the large pincers or chelae on their front legs.

The chelae have rough patches that act like a washboard. When the crayfish rapidly rubs its pincers together, the friction across these rough surfaces generates chirping or grinding noises.

Researchers believe crayfish stridulate on land for several reasons:

• Territorial warnings – Stridulation sounds let other crayfish know that a territory is occupied. The noises help establish boundaries and send warnings.

• Predator alerts – The stridulating may also warn nearby crayfish of approaching predators, signaling them to seek shelter.

• Mating calls – Some species appear to use stridulation as a mating call to attract partners. The sounds help potential mates locate each other.

So next time you come across a crayfish out of water, listen closely and you may hear the soft chirps or rasps as it stridulates. Just don’t get your fingers too close to those snapping pincers!

Vibrations Around Burrows

Some species of crayfish spend a lot of time out of water and dig complex burrow systems. These provide protection, shelter, and moist environments. When occupying their burrows, crayfish often generate vibrations that cause the surrounding ground to vibrate.

Researchers believe these vibrations are a form of communication between individuals inhabiting interconnected burrow networks. The crayfish likely send signals back and forth about predators, food sources, and reproductive status.

If you sit very still near an active crayfish burrow, you may be able to feel the faint vibrations coming through the ground as the crayfish communicates with its neighbors.

Hissing Noises When Threatened

Crayfish can also produce a hissing sound by forcing air quickly out of openings near their mouthparts. This most often happens when the crayfish feels threatened or is abruptly handled.

It’s thought that the hiss acts as an alarm to scare potential predators. Crayfish may also hiss when fighting over territory, establishing dominance for mating, or competing over food sources.

Some compare the hissing sound to that made by a cat or angry goose. It’s loud enough to be audible above water and warns that the crayfish’s claws are ready for pinching! So if you hear a crayfish hiss, it’s best to give it some space.

Unique Tail-Flipping Sounds

When startled or trying to escape danger quickly, crayfish rely on tail-flipping. This reflex action curves the tailfan under the body and propels the crayfish rapidly backward by releasing stored energy.

The swift tail-flip motion makes a distinct clicking sound underwater as the tail plates snap against each other. Above water, the tail-flip may make a softer sweeping noise as the crayfish shoots away from the threat.

Listen for these tell-tale noises of a tail-flipping crayfish if you startle one in the wild. It’s a key indicator the crayfish feels in danger and is making a speedy retreat!

Variations Between Species and Situations

It’s important to note that not all crayfish species make the same sounds. Some are quite vocal while others are more silent. Sounds can also vary based on the crayfish’s age, size, habitat, and situation.

Here are some key differences:

• Smaller crayfish often can’t generate as loud or deep sounds as larger, older individuals.

• Species adapted to spending more time on land may stridulate more frequently than strictly aquatic species.

• Crayfish in mating mode may make more chirping sounds than those not courting.

• Noises tend to be louder and more frequent when crayfish feel threatened or are fighting over territory and resources.

So the next time you encounter a crayfish, take a moment to appreciate the diversity of sounds these freshwater creatures can create. With a little luck, you may just hear them click, rasp, hiss, or tail-flip their way through the underwater world!