What is the difference between lobsters and crayfish by sja20118


									No. 10294            October 2000

What is the difference between
lobsters and crayfish?
Lobsters and crayfish are decapod Crustacea          Rock lobsters and spiny lobsters
Lobsters and crayfish are similar crustaceans.       The most familiar large marine crustaceans in
They are usually aquatic animals with a hard         Australia are called rock lobsters, but are better
skin (an exoskeleton) over a segmented body.         known as spiny lobsters in the rest of the world.
The Decapoda, the group of Crustacea to which        The older traditional names, crayfish or cray,
all lobsters and crayfish (and prawns, shrimps       are still often used but invite confusion with
and crabs) belong, have five pairs of legs on the    freshwater crayfish, which are quite different.
main part of the body, plus five pairs of            Unlike the European or American Lobsters,
swimmerets on the abdomen or tail. It is the         spiny lobsters do not have large claws; the first
muscular tail, and sometimes the legs and claws,     pair of legs are only slightly fatter than the other
that are edible.                                     four pairs.

All lobsters and crayfish produce eggs, which
are carried by the adult female attached to the
swimmerets under the tail. (In Australia,
catching or selling females in this condition is
generally not allowed.) When the eggs hatch,
the young swim out to sea, where they spend up
to a year before returning to settle near the

Different kinds of lobsters and crayfish
The classification of the Decapoda is very
complex, even to a carcinologist (a scientist who
studies Crustacea). The words ‘lobster’ and          Western Rock Lobster
                                                     Copyright C Bryce
‘crayfish’ are used in various combinations to
describe many different decapods.                    In Australia two species are commercially very
                                                     valuable. The Southern Rock Lobster is caught
Lobsters                                             in south-eastern Australia, where it is sold fresh,
The only ‘true’ lobsters are marine and have a       frozen or live in restaurants. In southern
pair of enormous edible flat claws. There are        Western Australia the Western Rock Lobster is
two very similar species: the European Lobster,      caught in large numbers. Dozens of other
found on the Atlantic coast of Europe and            species of spiny lobsters are fished in other parts
Scandinavia and in the Mediterranean, and the        of the world.
American Lobster, found on the Atlantic coast
of North America. The claws are the first of the     Crayfish
five pairs of legs; the second and third pairs end   Crayfish are freshwater crustaceans that inhabit
in small pincers. True lobsters are not sold in      rivers, lakes or dams. There are no marine
Australia.                                           crayfish – in spite of the colloquial use this
                                                     name for the spiny lobsters. Freshwater crayfish
No. 10294 October 2000

have a pair of large claws, two pairs of legs       Scampi
ending in pincers, and two other pairs of simple    Scampi, also known as Norwegian Lobsters or
walking legs.                                       Dublin Bay Prawns, are relatively abundant in
                                                    Europe, but the Australian species are relatively
The most familiar crayfish to Australians is the    rare and expensive. Scampi have long thin claws
Yabby, caught in dams on a bait of smelly meat.     and two pairs of legs with pincers. There is a
Yabbies are reared on commercial farms for          deep-water Scampi fishery in north-western
restaurants. A much larger species is the Murray    Australia, but most Scampi in fish shops in
Crayfish, also called the Spiny Cray.               Australia come from New Zealand.

The equivalent animal in the USA is the
Crawfish, most famous in southern states like

                                                    Copyright CSIRO

                                                    Further reading
                                                    Fallu, R, 1994. Yabbies for Fun, Fishing and
                                                    Farming. Department of Food and Agriculture:
Copyright E Tsrylin
                                                    Holthuis, L B, 1991. Marine Lobsters of the
Bugs                                                World. An Annotated and Illustrated Catalogue
What the rest of the world call slipper lobsters,   of Species of Interest to Fisheries Known to
Australians call bugs. Two sorts of slipper         Date. FAO Species Catalogue, Volume 13.
lobsters are sold in Australia. Both look like      Food and Agriculture Organization: Rome.
flattened lobsters without the claws. The feelers   Kailola, P J, Williams, M J, Stewart, P C,
(antennae), instead of being thin and whip-like,    Reichelt, R E, McNee, A and Grieve, C., 1993.
are plate-like attachments in front of the eyes.    Australian fisheries resources. Bureau of
The Balmain Bug from southern Australia has         Resource Sciences, Department of Primary
eyes near the middle of the body, and the           Industries and Energy, and Fisheries Research
Moreton Bay Bug from northern Australia has         and Development Corporation: Canberra.
eyes at the side.                                   Museum Victoria 2000. What is the difference
                                                    between prawns and shrimps? Information
                                                    Sheet 10295.
                                                    Yearsley, G K, Last, P R and Ward, R D 1999.
                                                    Australian Seafood Handbook. An Identification
                                                    Guide to Domestic Species. CSIRO Marine
                                                    Research: Hobart.

                                                    Internet resources
                                                    Crustaceans of southern Australia:

Balmain Bug
Copyright R Blackwood

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