A freshwater Crayfish

Signal Crayfish VS White Clawed Crayfish

When I was a lad many moons ago it was quite rare to see a crayfish in our waterways. Nowadays it’s hard work to find water that doesn’t hold these lobster-type creatures. But what type of crayfish do we have here in the UK?

Where did these strange-looking crustaceans come from, and are crayfish a native species? 

In this article, I shall answer all these questions and more, after all, you want to know what you are dealing with if you catch one of these critters. Let’s start by seeing what exactly a crayfish is.

What is A Crayfish?

A crayfish is a small-looking freshwater lobster. 

They are common in most countries across the globe but particularly abundant in America and Europe.

They can live in almost all types of water such as canals, rivers, lakes, and ponds. They have four legs for walking and four legs with claws. Two of which are bigger than the rest for ripping and catching food.

Crayfish will battle each other to the death often pulling each other’s claws off. If this happens the claw has the ability to grow back, though often quite a bit smaller than the original one.

Where Can I Find Crayfish?

As I just mentioned above crayfish can be found in most types of water all around the world. As long as the water is of good quality and not polluted the crayfish will be more than happy to reside there. Once the water has crayfish introduced to it, it is extremely hard to get rid of them all. For this reason, fisheries can struggle when these crustaceans are present. 

A crayfish with lots of eggs
A female crayfish with all her eggs

Crayfish reproduce on rather a large scale. A female can lay hundreds of eggs at once. So if you catch or see a cray it is almost certain there will be a lot more of the little buggers lurking on the bottom.

Which Crayfish Are Native To The UK?

In the UK we have two types of crayfish, the American signal crayfish, and the native white claw. The white claw is the only crayfish that is native to the UK but is sadly rapidly declining. It is quite hard to come across a white-clawed cray nowadays

The Difference Between Signal Crayfish And White-Clawed Crayfish

The White Clawed Crayfish

In general, the white-clawed crayfish grows between 6 and 12 cm in length. They are bronze in colour and the underside of their claws is a pale colour, hence how they get their name the white-clawed crayfish.

These are generally not as aggressive as their American cousin and live on average between 8 and 12 years.

The native white-clawed crayfish
The native white-clawed crayfish

The American Signal Crayfish

The American beast is a lot bigger in size than the white-clawed and grows to a size of 16 to 18 cm in length. Unlike the white claw, the signal crayfish has red claws rather than white.

The signals are much more likely to try and attack you if you catch one, they are generally more aggressive.

The American signal crayfish
The non-native American signal crayfish

If you do catch one in the UK you have to kill it as humanely as possible and NOT throw it back in.

Should I Kill Crayfish?

The white-clawed crayfish population in the UK is being decimated due to its larger cousin the signal crayfish. Not only are the signals bigger in size and more aggressive, they also carry a disease that kills our native crays. The signals are immune to this disease, unfortunately, the white-clawed crays are not. This is proving to be a huge problem and has put the white-clawed crays on the endangered list.

For this reason, it is illegal to return any signal crays into the water. Potentially you could be putting hundreds of them back in if the crayfish is carrying eggs. Not only do they kill our native crays they also invade our fish’s habitats and feast on their eggs. Which in turn can damage the fish population quite considerably. So please do not return them to the water.

I find a blade straight in the back of the head is the quickest way of killing them.

Can I eat Crayfish?

Yes, you can eat crayfish, they taste a little like lobster. Just be sure to check that the crays are fresh and from clean unpolluted water.

The crayfish will need to be cleaned in water before boiling. 

Cooking these little beasts isn’t for the faint-hearted, they need to be boiled alive. Don’t worry too much though because they do die pretty much straight away.

There are lots of different ways of cooking with crays. Most of the recipes are pretty darn good as well.

What Fish Eat Crayfish?

The signal crayfish is a real pain in British waters. They devastate fish stocks and ruin their habitats. Fortunately for us lots of fish in our venues are quite partial to a crayfish dinner. All our predator fish will feast on them including pike, perch, zander, chub, and trout. Unfortunately, this is not enough for the numbers to decline.

A perch looking for crayfish
Perch are one of many fish that eat crayfish

For every cray that is eaten, hundreds more will be hatched out. We certainly won’t be seeing their numbers declining anytime soon.

To Conclude

Unfortunately, it seems as though the signal crayfish is here to stay in British waters. Even though they are an invasive species, that kills off our fish stocks and our native crays it is still illegal to capture them without a license. Yet if you catch one it is illegal to put it back, very strange if you ask me. 

If you do happen to come across these critters be sure to watch your fingers around them. They do have a bit of a pinch on them and can draw blood. I hope this article has given you a bit of an insight into signal crayfish VS white-clawed crayfish and helps you tell the difference, tight lines, and watch them fingers!!

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