Latin Name: At the present time there is some confusion over the identity of this crayfish. Older texts refer to it as Cherax misolicus or Cherax papuanus, however, Cherax sp. Zebra may be more correct until it is positively identified. Cherax sp. Tiger looks similar to Cherax sp. Zebra, but has yellow bands across the tail instead of white like the Zebra. Adult Size: 10cm to 15cm. Average Life Span: Unknown at the present time. Native Distribution: Irian Jaya? Physical Description: A medium-sized crayfish. Temperament: A predatory omnivore / detrivore that is best kept on its own or in an aquarium with many hiding places. Most all crayfish will cannibalize conspecifics if given the opportunity. Status in the Wild: Unknown at this time.
Native Habitat: Unknown at this time. Ambient Temperature: 22C to 28C. Water Chemistry: Tolerates a wide variety of water parameters (pH 6.5 to 8.5, medium to hard water). Lighting: Full spectrum fluorescent. Aquarium Size: Adults are best kept on their own in tanks of at least 10 gallons. If not given sufficient space or hiding places, young will cannibalize each other, mostly during molts. Aquarium Decor: Forest stream, marsh or lake motif. Aquarium Substrate: Gravel or sand. Aquarium Containment: A top cover is recommended. Crayfish can climb power cords and airline tubing to escape their aquarium.
Hygiene: Good filtration and / or frequent water changes are required to keep crayfish in top condition. Feeding: Crayfish eat between 1% and 4% of their body weight every three days, depending upon their level of activity. Crayfish enjoy tropical fish food flakes and pellets consisting of both meat and vegetable products. Their favorite food is other crayfish. Crayfish will often eat their own molts to regain otherwise lost nutrients. Fallen, dried oak leaves are eaten and are beneficial to their health. Handling: Not recommended. Aquarium Compatibility: Crayfish are predatory bottom dwellers that may be kept with other fish that stay away from them, or that are too large for the crayfish to catch.
Maturity: Unknown at the present time. Sexing: Adult males (cocks) are slightly larger than females (hens), have broader claws and have reproductive appendages on the first pair of walking legs. Females have genital pores on the third pair of walking legs. See sexing Cherax Crayfish photograph. Conditioning: Keep adults well fed. Cycling: Breeding may occur year round. Sex Ratio: Best bred in pairs. Egg Laying: The female carries the eggs (berries) on her swimmerets until they hatch, usually within 30 to 50 days of laying. Clutches range from fifty to several hundred 2mm black eggs.
Incubation Temperature: 23C to 27C. Incubation / Gestation Time: Variable - 40 days is the average. Size at Birth: 3mm to 5mm. Hatchling Sex Ratio: Not temperature dependant. Feeding: Live baby brine shrimp are best, however, crushed tropical fish food flakes will also be eaten. Growth of young is slow. Housing: Young may be raised together if given numerous hiding places and floor space to get away from each other. Some cannibalism is inevitable. Individuals that have lost one or both claws should be removed and isolated until the missing claws regrow.
Missing Legs and Claws: Keep in isolation for several molts until missing appendages regrow. Crayfish Plague (Aphanomyces astaci): Isolation and treatment with antibacterial and antifungal tropical fish medications. No known cure is available at this time. As a prophylactic against the crayfish plague, a dosage of 5g/l of MgCl2.6H2O (Magnesium Chloride hexahydrate) may be added to the aquarium water. Molting Problems: Increase water salinity and hardness with the addition of sea-salt.
Disclaimer: Any course of treatment should be preceded by a thorough examination from a qualified professional. All remedies for ailments given above are for reference purposes only.
Aqualog:Special-Serie Ratgeber, Rodgau:A.C.S., Shrimps, crayfishes, and crabs in the freshwater aquarium-2nd edition 2003 by Uwe Werner, English edition:ISBN 3-936027-08-0, pp. 52-56
