Feb 15

Another Valentine’s day has passed us by and it seems as though invertebrates have been overlooked. If our spineless friends had the capability to feel emotion, this would surely be a blow to their fragile self esteem.

One of my personal favourite invert groups are the crayfish. At a time of year when couples are demonstrating love for one another by dancing in the manner of a bird of paradise, or showing commitment by fusing with their other half in the in the style of a deep sea anglerfish, these enigmatic Arthropods are simply left out.

In the spirit of ARKive’s Love Species Campaign, I want more people to appreciate crayfish for what they are, so here is why I love them.

Freshwater lobsters

You might have noticed that crayfish strongly resemble lobsters in appearance, and that’s because they are, in fact, very closely related. Both groups belong to the infra-order Astacidea.

Unlike lobsters however, which are marine crustaceans, crayfish only inhabit freshwater systems such as streams and rivers. Generally speaking, crayfish are also a fair bit smaller than your average lobster, but some have been shown to reach truly massive sizes.

Owing to their riverine existence, crayfish are often referred to as freshwater lobsters, neatly leading on to my next point.

Freshwater white-clawed crayfish photo

Funny names

As a group, crayfish are rather cosmopolitan. They exist on a variety of continents and so people have labelled them with a host of interesting names. Focusing on the English speaking world, ‘craw’ seems to be a preferred prefix in the USA. Names there range from crawfish, crawdad and crawdaddy, all the way over to mudbug and my personal favourite; spoondog.

As always, Australia takes the cake for far-flung nomenclature, referring to a variety of crayfish species as yabbies.

Yabbie crayfish photo

The yabbie - crayfish are amphibious, able to traverse stretches of land between freshwater systems such as rivers and streams.

Crayfish plague my heart

Crayfish around the world are susceptible to a nasty fungal disease known as crayfish plague. Europe is currently seeing the worst effects, with the plague being highly lethal to native species such as the now Endangered white-clawed crayfish.

What’s worse, European species are being outcompeted by an invasive called the American signal crayfish. Not only is it larger and more efficient at catching food, but the American signal is resistant to plague. It acts as a carrier for the disease as it spreads across the continent, obliterating native European crayfish when entering new freshwater systems.

Common carp being fed on by an invasive species; the American signal crayfish

American signal crayfish feasting on a common carp. This species acts as a carrier for crayfish plague.

There you have it. I love crayfish because they look like lobsters, have a variety of strange names (bonus name; grave digger) and are threatened by a lethal fungal disease.

It’s all too easy to overlook less aesthetic species in favour of fluffier ones, but I hope this will inspire you to spare a thought for invertebrate life at this lonely time of year.

Robert Morgan, ARKive Media Researcher

  • Ben (February 15th, 2011 at 5:01 pm):

    Gotta love lethal fungal disease on Valentine’s day!