5 Australian Red Claw Crayfish 2+ Inch, Live Aquarium Crayfish For Sale The Red Claw crayfish is a new and very promising aquaculture species. The Red Claw is very similar to the native American species, except that it grows to a HUGE size, almost to that of a lobster! It 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 6-12 months, although they can reach up to 600 grams each. In a hatchery red claw can spawn almost continuously throughout the year if conditions are suitable. Red claw generally reach sexual maturity by the age of 6 to 12 months. Red Claw crayfish are easy and fun to raise in your tropical aquarium as unique pets.