There's no mistaking a crayfish. With beady eyes, strong claws, 10 feet and a tail that people the world over love to eat, the crayfish -- called a crawdad, mud bug or crawfish in the South -- proves the most popular crustacean to raise in the United States. While Louisiana hosts about half of the approximately 250,000 acres of crayfish aquaculture farming, California has its share of crayfish farms, especially in the Delta region around the Sacramento and San Joaquin rivers, where crayfish sometimes reach over 8 inches in length.
Choose a location for the crayfish pond where the temperatures range between 65 and 85 degrees F for a large portion of the year. Freezing temperatures do not kill most crayfish in the United States; they become inactive instead, burrowing under rocks or, more commonly, in burrows sometimes measuring 6 inches or more in depth below the water or along pond banks. High temperatures also induce burrowing, and crayfish do not grow during these periods, so proper temperatures encourage good growth.
Dig a pond if a suitable one doesn't already exist. Clay soil and a fairly flat location are ideal for a crayfish pond. Crayfish are sometimes raised within berms -- built-up walls of soil -- surrounding rice or other crops, but a large pond free of brush and trees is also suitable. Make a shallow pond covering up to 20 acres and up to 16 inches deep for high production.
Fill the pond with rain, spring or well water. Avoid water contaminated with pesticides. While crayfish easily adapt to a wide range of conditions, monitor water conditions. Maintain pH levels between 5.8 and 8.2 with an oxygen concentration of 3 parts per million or greater. Test and treat for other quality considerations, such as water hardness and alkalinity (50 ppm or greater), ferrous iron (less than 0.1 ppm), hydrogen sulfide (less than 0.002 ppm), un-ionized ammonia (less than 0.06 ppm) and nitrites (less than 0.6 ppm), advises the Southern Regional Aquaculture Center. Salinity should not register higher than 6 parts per thousand (ppt).
Place rocks, logs and vegetation in the pond to provide the crayfish with hiding areas. While crayfish will eat some of the vegetation, they avoid plants with a coarse texture, so these are ideal for a crayfish pond, especially along the edges.
Plant other water plants for crayfish to forage. Crayfish eat just about anything, as the Southern Regional Aquaculture Center notes. Not only are they herbivores, they are also detritivores (consuming decomposing matter), omnivores and "obligate carnivores" -- meaning they require some animal matter for ideal growth. Thus, decaying plants or crops prove suitable for crayfish.
Supplement the crayfish diet with processed feeds, such as dog or cat food, fish food or specialty crayfish food, if desired. Many crayfish operations in California do not feed their ponds with commercial foods, but this depends on the environment involved. In their natural environment, crayfish get at least 20 percent of their nutrition from worms, insect larvae, algae and other microscopic elements. Rich pond environments, properly vegetated, should sustain their own food production.
Install aeration devices, especially in smaller ponds. Paddle wheels, pumps and other aerators ensure your crayfish do not smother with a lack of water oxygen, especially when temperatures rise and oxygen levels decrease.
Stock the crayfish pond with your preferred crayfish species in the spring -- April or May. Each acre of pond can sustain from 40 to 60 pounds of crayfish -- crayfish turn into cannibals when crowded in addition to growing smaller. Choose from any species available for your area of California; the signal crayfish is indigenous to California and does especially well in the Delta region. Southern favorites, the red swamp and white river crayfish, also perform well in California.
Drain the water from the pond between May and August. The crayfish retreat into burrows characterized by a volcano-like opening. Inside, the female broods over eggs which later release, repopulating the pond with the next generation. While the water is absent, crops or other vegetation may grow, providing food for the next generation.
Flood the crayfish pond again around October. Cooler areas in California will flood sooner, and warmer areas later. As the water soaks the plug closing their burrows, the crayfish will emerge, repopulating the pond.
Begin harvesting late in November, continuing until the following spring. Repeat the process the following May, skipping the stocking if you notice evidence of sufficient numbers of crayfish still growing. Crayfish generally live a couple of years, growing larger as they age.