''Cherax quadricarinatus'' (known by several
common name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...
s, including Australian red claw crayfish, Queensland red claw, redclaw, tropical blue crayfish, freshwater blueclaw crayfish) is an Australian freshwater
crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
.
Distribution and ecology
''C. quadricarinatus'' is native to permanent freshwater streams,
billabongs and lakes on the north coast of the
Northern Territory, northeastern
Queensland, and
Papua New Guinea.
Through translocation by humans, the range has spread down to southern Queensland and into the far north of
Western Australia. ''C. quadricarinatus'' is considered an
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
, and has established feral populations in
South Africa,
Mexico,
Jamaica,
Puerto Rico,
,
,
and
Singapore.
This tropical crustacean is very tolerant of environmental changes, and is primarily a
detritivore
Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...
.
Description
The colour of ''C. quadricarinatus'' ranges from dark brown to blue-green and adult males have a distinct red patch on the outer margin of the
claws.
They can reach up to .
Life cycle
Females, which are smaller than males, spawn 300–800
olive-green eggs per brood,
which are
fertilised
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...
from a
spermatophore which the male has deposited at the base of her walking legs (
pereiopod
The decapod (crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various g ...
s) during mating. Fertilised eggs are affixed to the female's pleopods, situated on the underside of the tail. Incubation takes approximately six weeks and the newly hatched juveniles rapidly become independent.
Aquaculture
''C. quadricarinatus'' is farmed commercially in Queensland and the Northern Territory, and is harvested at between .
''C. quadricarinatus'' is a sought-after product with a delicate crustacean flavour. They are both non-aggressive in nature as well as highly fertile, and can therefore be bred in large numbers in captivity. Time to
sexual maturity, and therefore harvest size, is somewhere between six and twelve months in optimally farmed conditions.
References
External links
Freshwater crayfish (Redclaw)fisheries information
{{Taxonbar, from=Q1417029
Parastacidae
Freshwater crustaceans of Australia
Crustaceans described in 1868