All you need to know about the invasive species of britain.
For the people who don't know, invasive is an animal that can be found in a country, but isn't native there. For example the Brown Rat was actually only native to Central Asia but were intr...
The Signal Crayfish arrived into Europe from North America in the 1960s to supplement the North European Noble Crayfish fisheries, which were being damaged by the crayfish plague, but the imports turned out to be a carrier of that disease.
Facts
The Signal Crayfish is a North American species of crayfish.
Signal crayfish can live for about 20 years, and are at sexual maturity at 2 to 3 years.
Signal crayfish are basically the sea equivalent of grey squirrels, you'll see why later, it's gonna make a lot of sense.
Problems
Signal crayfish cause problems for Britain by burrowing into river and canal banks which causes erosion, bank collapse and sediment pollution. Thanks a lot LARRY. Don't care that he's a lobster, still looks like a crayfish.
On top of that Sebastian thought it would be a good idea to be a predator and feed on a variety of our fish, frogs and invertebrates. The frogs are really getting it from these invasive species aren't they?
On top of THAT they even eat THEMSELVES, which, to be completely honest, can be quite common in several animal species like nurse sharks and that one time Peppa got peckish and ate bacon (remember that traumatising video? And yes, pigs can be cannibals)
Another problem caused by these is the fact that, through the spread of the crayfish plague, they're driving the native crayfish to extinction in the UK, also because the signal crayfish are bigger, grow-faster, reproduce more quickly and are more tolerant of a wider range of conditions that the natives can't handle. (Sound familiar, SQUIRRELS?!?)
Now let's get onto some of the basic facts of these cannibal crustaceans.
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Population Status Least Concern
Diet Omnivorous, we went over this before. Other things that they will eat is fish eggs, other amphibians and freshwater invertebrates
Weight 60-110g
Size 16-18cm
Native Location North America, west of the Rocky Mountains, including the Canadian province of British Columbia, and the U.S. states of Washington, Oregon and Idaho.
Habitat Still and slow-flowing freshwater environments such as rivers, streams, lakes, redivided and canals, it can also survive in slightly salty water. Ifyou see a random 3ft hole, it's probably been burrowed out by one of these.
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Predators
The land animals that will prey on signal crayfish include otters and the American Mink (another invasive species that we'll be going through)
Animals that will hunt crayfish that lurk in the waters are Atlantic Salmon and European Eels.
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A lot like the bullfrog situation, if you see one of these, report it, or, even better. Just straight up kill it. That what The Environment Agency in Scotland has urged their fishermen to kill them on sight. As heartless as that sounds these are the sea equivalent of the little gimp grey squirrels and it would be saving the sea equivalent of the red squirrels so there you go!
Hoped you learned something new about the signal crayfish, remember to stomp those tramps out of the Earth if you ever fish one up, or maybe feed them to the French. They'll eat anything.
