Y
abbying has always been a part
of growing up in the Australian
bush. A stroll to the nearest dam,
a length of twine, a chunk of smelly old
meat, and patience - these are all you
need to catch a tasty entree.
But there’s more to the yabby than
dinner. The common yabby has the
perfectly awesome scientific name Cherax
destructor, and is one of 57 Cherax
species. Before settlement, Cherax
yabbies were mostly restricted to lowland
streams, rivers and lakes. Unlike many of
the other freshwater crayfish, Cherax
destructor can survive dry spells by
digging a muddy burrow, sealing itself off
from the outside world, and entering a
period of very low metabolic activity.
Common yabbies can even cross
kilometres of open ground to find a new
body of water to call home. Which explains
the uniquely Australian experience of
running over one with your lawnmower...
Even though the species is listed as
vulnerable, the IUCN seems to have
missed the thousands of dams we’vedotted across the landscape, which have
provided yabbies with a network of watery
“stepping stones” to expand into new
habitats. Populations today are strong.
Aussies tend to call every freshwater
crayfish a “yabby”, but there are dozens
of species in several genera. Mountain
kids will be familiar with the more
spectacular Euastacus yabbies, such as
Euastacus spinifer. These yabbies tend
to be larger than Cherax destructor, and
are adorned with spikes.
Traditionally, a yabby goes straight in
the pot (or back in the dam to make more
yabbies), but in recent years, aquarium
enthusiasts have discovered that Cherax
destructor makes a hardy and interestingaddition to many tanks. While a yabby will
have a go at fish, mostly it just eats
detritus. Even so, these animals can be
very fascinating to watch as they trundle
around the aquarium. Thanks to relatively
good eyesight, a yabby will often react as
you walk past the tank - raising its claws
in challenge or scooting away into a
burrow it dug under the plastic skull.
Unlike so many other native animals,
overall Cherax destructor seems to have
benefited from the settlement of
Australia and the spread of agricultural
land. So here’s to the common yabby:
may it remain an intrinsic part of
Australian childhood for many
generations to come.TRIVIA ANSWERS 1. Islam 2. Humours 3. The rings of Saturn 4. Truck 5. True (though it may not bear fruit) 6. European rabbits 7. Alcohol 8. They hope it will finish being built 9. Clouds 10. Shadow
Trivia Countdown – Name this animal: Seahorse Name this historical character: Benjamin Franklin Name this country: Italy82 | SCIENCE ILLUSTRATEDSPECIES:
Common Yabby (also
Blueclaw Yabby)
SCIENTIFIC NAME:
Cherax destructor
DISTRIBUTION:
Throughout NSW,
Victoria and QLD, an
introduced pest in
Western Australia
ICUN CONSERVATION
STATUS: Vulnerable
(disputed)GO BIG OR GO HOME
Tasmania is home to Astacopsis gouldi, which is, of
course, the world’s largest freshwater crayfish.
Because it’s a giant freshwater crayfish, it is known
as the... uh... Giant Freshwater Crayfish. This beast
has been recorded growing to over 80cm long and
weighing six kilos! Today, it is endangered, with
perhaps less than 100,000 remaining. Most weigh a
mere 2-3kg, which is still enormous for a yabby.BIODIVERSITY CRUSTACEA