What’s a burrowing crayfish?
Usually all you see of a burrowing crayfish is the opening to its burrow – a 2-5 cm diameter hole in the mud. Below the surface, however – sometimes a metre or two below, depending on how far it needs to burrow to reach the water table – is a little crayfish.
Often the hole is easy to spot, as it’s surrounded by a ‘chimney’ made out of the burrowed mud from the hole, which can be anywhere from barely noticeable to more than 30 cm high. On the other hand, it may still be hard to see if it’s hidden by vegetation such as ferns or blackberries.
And… no, you wouldn’t want to try to eat a burrowing crayfish. They look more or less like other crayfish, yabbies and lobsters – but they’re typically only about 10 cm long, and they have tiny tails.
What’s the Central North burrowing crayfish? And isn’t it everywhere?
The chimneys of various species of burrowing crayfish can be seen across Tasmania, but the highly threatened Central North burrowing crayfish (Engaeus granulatus) exists only around Devonport and Latrobe, mainly between the Mersey River and Port Sorell. Nowhere else in the entire world.
Not only that, but the small, isolated and fragmented populations so far discovered cover a total area of less than 100 ha. This means that it’s listed as Endangered by the Tasmanian and Commonwealth governments, and as Critically Endangered on the IUCN Red List.
If I have Central North burrowing crayfish on my land, what does that mean?
According to our current understanding of where the species is found, that makes your land quite unusual and special.
However, it’s unlikely that it’s going to make a big difference to your everyday activities. This crayfish typically only takes up a little bit of space, and all it needs is for that little bit of space to remain reasonably damp (ie not be drained or cleared), and not to be heavily compressed – for example by vehicles or cattle.
If you would like to know more about how to help this endangered species, find out more on its Threatened Species Link profile … and join in with the Claws on the Line research.