Redclaw Crayfish: Tasty Freshwater Lobsters
The Australian Redclaw Crayfish is a new and promising species for aquaculture enthusiasts. In the state of Florida, you must have a Florida Aquaculture License to own Australian Redclaw Crayfish.
The Redclaw Crayfish is very similar to the native American species, but it can grow to a huge size comparable to a lobster! This means the species has considerable potential for commercial culture. The fact that it can withstand low oxygen levels and thrives in warm waters makes it well-suited to aquaculture and aquarium life as well. The Australian Redclaw Crayfish does best when water temperatures are between 75˚ and 85˚ F.
The Redclaw Crayfish is a tropical freshwater crayfish native to Australia. They are often called "freshwater lobsters" because of their physical resemblance and large size. They are valued as both a food source and as an ornamental species.
The Redclaw Crayfish is the more common species of "yabby" in the Northern Territory and is found in most lakes and rivers in North Australia as it thrives in tropical freshwater environments. In nature, these creatures are often found under roots or rocks where they hide from predators.
Appearance and Meat
Redclaw Crayfish have a smooth, lustrous shell that is deep blue to green in color. Males have a bright red coloring on the margins of their large claws, thus the name "Redclaw." The blue color intensifies when the water is clean; the animals are a more green/brown when left in brackish water. Additionally, the blue color intensifies as the crayfish matures.
This crustacean is one of the largest freshwater crayfish in the world. Average market sizes of 50 to 150 grams (1 pound - 454 grams) are achievable in six to 12 months, though they can reach up to 600 grams each.
When cooked, they present as bright red, typical of premium crustaceans. Redclaw Crayfish is considered a delicacy, comparing favorably with other commonly eaten marine crustaceans. The meat is arguably more healthy than traditional seafood, however, since it is low in fat, cholesterol and salt.
Redclaw lobsters are scavengers. They are a bottom dweller and will eat anything they come across, as they are opportunistic eaters. They will eat all of the leftover food your fish miss, as well as detritus and other waste off the bottom of your aquarium. Although this lobster will eat dead or dying fish as well, it is normally too slow to catch healthy fish.
A healthy diet includes both vegetables and animal proteins. The primary diet should include plant matter, worms, brine shrimp, bloodworms, or insect larvae, and can include vegetable matter waste from aquaponics systems such as lettuce, shredded carrots, zucchini, etc. Adding a high-protein fish or shrimp sinking pellet, flake food, and dried algae is also recommended.
To be successful in the maintenance and reproduction of brood stock in indoor holding systems, be sure to:
* Select healthy mature adults
* Maintain warm temperatures (preferably between 75˚ and 85˚ F)
* Maintain good water quality
* Provide proper nutrition
* Isolate berried females (females carrying eggs) to hatching tanks
In a hatchery, Redclaw can spawn almost continuously throughout the year if conditions are suitable. They generally reach sexual maturity by the age of six to 12 months. As noted earlier, mature male Redclaw develop a distinctive red or orange patch on the outside margin of the claws; animals of this same size without the reddish claw patch are usually females. The sexes are best identified, however, by examination of the genital openings on the underside of the cephalothorax at the base of the walking legs. Females have a pair of genital pores at the base of the third pair (counting from the head) of walking legs. Males have a pair of small genital papillae (small projections) at the base of the fifth pair of walking legs.
Individual females do not spawn when going through a growth phase (i.e.,moulting). Each female will produce 100 to 1,000 eggs per spawn depending on her size and general health. The first spawn of young females usually has fewer eggs than latter spawns. Newly spawned eggs average 10 eggs per gram of female. About 30 percent of the eggs are lost during incubation, resulting in an average of 7 eggs (that hatch) per gram of female. For example, a female weighing 3 ounces (85 grams) would produce about 600 eggs. This can be used to estimate the number of eggs a female of a given size will produce.
Broodstock and Hatchery
Mature broodstock Redclaw Crayfish can be kept at a density of one to two animals per square foot of tank bottom. The ratio of females to males in each tank should be between one and four females for each male. Good spawning success has occurred using tanks with water depths of 1 to 3 feet. Small rectangular tanks of 15 to 20 square feet have been used successfully, as well as large circular tanks of 15 feet in diameter with 1 to 3 feet of water. For example: A 20-square-foot tank that is 2 feet deep could be stocked with five to 10 males and 15 to 30 mature female Redclaw. Broodstock tanks should maintain a water temperature between 75˚ and 85˚ F for optimal reproduction.
Breeding tanks should be checked every one to two weeks for berried females. Once the fertilized eggs are affixed to the female's pleopods, "swimmeretts" situated on the underside of the tail, It is highly recommended that berried females be moved to a separate tank. Berried females should be carefully netted, keeping them with their abdomen curled around the eggs during transfer to hatching tanks. (to prevent egg loss). Incubation takes approximately six weeks and the newly hatched juveniles rapidly become independent. The hatching tank will then become the nursery tank for raising the young Redclaw.
While Redclaw Crayfish have a low level of aggression, "homes" are essential. PVC pipe sections in multiple sizes, mesh bags, burlap, rocks, or anything that the crayfish can climb through and hide in for shelter will suffice. Young crayfish will moult many times during their first year of life, as they grow quickly, while mature Redclaw will moult only once or twice a year. The shed exoskeleton (moulted shell ) is used as a source of calcium and is typically eaten by its owner or other crayfish. Redclaw in tanks can handle a temperature range from 60˚ to 90˚ F. Temperatures below 55˚ and above 95˚ F will result in casualties.
Australian Redclaw As Pets
Redclaw Crayfish, with their exotic coloration, are easy and fun to raise in your tropical aquarium as unique pets. They are less aggressive than most crayfish, and reproduce rapidly and easily. One Redclaw Crayfish can inhabit a 25-gallon aquarium, while a 40-gallon aquarium with plenty of caves and space to move around can support two. The larger Australian Redclaw Crayfish requires a tank that is at least 40 inches long and 20 inches deep.
The ideal tank environment consist of about 5 inches of aquarium sand or gravel on the bottom with pipes, tunnels, decorative rocks and caves. You can plant hardy plants in the aquarium, but small, weaker plants won't survive. You will want to make sure the aquarium has a filter to keep the aquarium clean, and combine that with periodic partial water changes. Use test strips to monitor the pH levels which should be between 6.5 and 8. When cleaning the tank, test the pH before and after changing the water to ensure levels remain within the proper range. Use an aquarium heater and thermometer to measure the water temperature and maintain the aquarium between 77˚ and 90˚ F. Temperatures below 55˚ or above 95˚ will result in casualties. Test the water hardness, as well; they need hard water to thrive. You can add limestone to make the water harder if necessary.
Plenty of cover should be included in the aquarium, including both rocks and plants, though the plants will not last long as the crayfish get larger. After moulting the crayfish is vulnerable to attack and consumption by others. If the exuvia (shed exoskeleton, moulted shell) is removed from the tank after shedding, the crayfish will likely die as this shed should be consumed for vital calcium. However, If your water has enough calcium in it, this will not be an issue.
It's important to note that Redclaw Crayfish are excellent escape artists! If the water level is near the top of the tank, if you have rocks and decor large enough for them to reach the surface, or if equipment such as airline tubing or heater cords extend over the side of the tank, they will climb out. To reduce the likelihood of escape, equipment should be suspended overhead so that it does not touch the sides of the tank. If housed in an aquarium, a lid may be required.
Crayfish or Crawfish - Which is Correct?
People often wonder whether the term "crayfish" or "crawfish" is correct. The answer? They are both correct! Crayfish are freshwater crustaceans resembling small lobsters. They are also known as crawfish, crawdads, freshwater lobsters, mountain lobsters, mudbugs, or yabbies.
The Redclaw Crayfish or Cherax quadricarinatus, is also known by several other common names including Australian Redclaw Crayfish, Queensland Redclaw, Redclaw, Tropical Blue Crayfish, Freshwater Blueclaw Crayfish, Redclaw Crayfish, Blue Lobster, Australian Crayfish, Australian Crawfish, Freshwater Crayfish, North Queensland Yabby, Yabby, Yabbie and Queensland Redclaw to name a few.
To learn more, visit the Crayfish page on this website. Live Aquaponics also sells a high-protein crayfish food perfect for raising Redclaws. If you have any questions about raising Redclaws, feel free to contact us. We love to talk with our customers.