Blue Yabby (Cherax destructor destructor)

Blue Yabby Cherax destructor destructor
Name	Blue Yabby
Name Lat.	Cherax destructor destructor
Family	Southern Hemisphere Crayfishes
Family lat.	Parastacidae
Order	Decapods
Order lat.	Decapoda
Origin	Australia (breeding variety)
Habitat	Streams, lakes, swamps
Diet	Carrion, leaves, crayfish food
pH	7.0-8.0
Behavior	Semi-aggressive
Keeping	Individual, pair, group
Care Level	Moderate
Reproduction	Oviparous
Breeding	Moderately difficult
Life Span	5-7 years
Protection	No
Metric Units
Size	15-20 cm
Temperature	12-25 °C
Hardness	5-20 °dH
Aquarium	~ 200 l
US Units
Size	6"-8"
Temperature	54-77 °F
Hardness	89-356 ppm
Aquarium	~ 50 gal

Distribution and habitat

The Blue Yabby is a breeding form. The range of the wild form of the Yabby extends in Australia throughout Victoria and New South Wales to the areas of the Northern Territory. They live in stagnant and slow-moving, usually turbid waters with dense vegetation. They are also frequently found in channels and swamps.

Maintenance

They need a well-structured aquarium with roots, stones and robust plants, with hiding places (caves, crab tubes) and a moderate current. The substrate should be sand or gravel, partially covered with foliage (e.g. sea almond leaves, oak leaves).

No ammonia, ammonium and nitrite should be detectable in the aquarium water, the nitrate value should not exceed 100 mg/l. To ensure water quality and oxygen content, a filter and heater adapted to the size of the aquarium is required, as well as lighting for the species-appropriate day-night rhythm of the animals. When choosing the filter, special care should be taken to ensure that the animals cannot be sucked in.

Diet

They feed on animal organisms, carrion and dead plant material. They prefer live food, such as daphnia, artemia and fish, which is also accepted in frozen form, as well as foliage (e.g. oak, beech, maple, birch), food tablets, granulated and flake food. Occasionally, vegetable food in the form of spirulina, kelp or scalded leafy vegetables should be offered.

Regular and varied feeding promotes health and prevents deficiency symptoms. Unaccepted food must be removed after 2-3 hours.

Behaviour and compatibility

They behave aggressively within the species, but also towards other crayfish, therefore keeping several pairs or groups is only recommended in a much larger and richly structured tank. They can only be socialized with large shrimps, snails and large fish, such as perches, but it is better to keep them in a species tank.

Basically, only mutually compatible animals with similar demands on water conditions and water temperature should be socialized.

Reproduction and breeding

Males can be identified by the gonopods (mating styli) on the abdomen of the underside of the body. During mating, the male turns the female onto her back shortly after her molt and transfers a sperm package with his gonopods. The female carries the eggs (30-40 of them) on her pleopods (webbed feet) and supplies them with oxygen by movement (fanning). Dead or non-developing eggs are eaten by the female. The young hatch after about 4 weeks.

Important

It can happen that a crayfish is missing a claw. Mostly these are females that have lost a claw during mating. The missing claw slowly grows back during the following molts. The strong claws are also used for digging.

The well-being of the animals should be checked regularly. Temperature should be checked daily, pH, hardness and nitrate levels at least every 14 days. Regular partial water changes are recommended, even if the contaminant level has not yet reached the upper limit. Sudden changes in water quality should be avoided. Newly introduced animals must be accustomed slowly to the water in the aquarium.

Further literature can be found in your pet store.

References

Text: Barbara Pachner; Image: Franz Lowak

Source: LUKHAUP & PEKNY (2008): Süßwasserkrebse aus aller Welt, Dähne Verlag; ENGELMANN & LANGE (2011): Zootierhaltung - Tiere in menschlicher Obhut: Wirbellose, Verlag Harri Deutsch