Aqua Farming Crayfish Beginner Guide

Crayfish are small, freshwater crustaceans which are approximately 500 different species which can live up to 20 years and can reach the largest weight of 5 kg (11 pounds).

However, the species are different as per their location hence their descriptive characteristics. Other names of crayfish are; crawfish, crawdads, crawdad-dies or mudbugs. Crayfish vary in colour depending on the species and age.  

Few Facts About Crayfish

• Never move live crayfish of any kind from one water body to another because this can cause harm in the water bodies in did not inhabit in. Even the native crayfish should not be moved.
• Female crayfish can store sperm for a long time, so a misplaced crayfish has a potential to establish a population.
• Crayfish are commonly found in many parts of the world.
• It can be used as live bait to live pets and many other different settings such as restaurants and laboratories.
• Invasive crayfish threaten native fish, amphibians, native crayfish and plants by eating them directly or by competing for food and shelter; hence their elimination is extremely difficult and expensive. 

Crayfish Species

There are crayfish range that are native and invasive; making the red swamp, virile, ringed and rusty to be the native range as they are found in areas such as Rocky Mountains. Below are some species;

• Rusty crayfish (Orconectes rustics) resemble the ringed crayfish, with similar body color and black- and orange-tipped claws.
• However, the sides of their carapace typically have a large, rust-clolored circle. In both species, these markings are not always present or well developed. Rusty crayfish typically reach about 4 inches in length as adults.
• Ringed crayfish (Orconectes neglectus) are olive-green to red-tan in color. Ringed crayfish can often be identified by the combination of prominent black and orange rings at the tips of their claws and a dark bar on the side of the carapace. Generally, ringed crayfish are between 1.6 and 3.6 inches in length as adults, but females can reach 5 inches.
• Virile crayfish also known as northern crayfish (Orconectes virile) are rust-brown in color with blue-green claws that may have orange tips. In adults, the claws have obvious, whitish bumps. Virile crayfish are some of the largest crayfish in their native range, reaching 5 inches in length.
• Red swamp crayfish (Procambarus clarkii) are typically dark red and range from 2.2 to 4.7 inches in length as an adult. Juveniles are usually a whitish-gray color and much smaller.
• Adults have long, narrow pincers (chelae) that are bumpy with bright red spots.

Crayfish habitation (site location)

The red claw crayfish is native to upper rivers in the Northern Australia and other places; they habit preferably in high turbidity, slow moving streams or static holes (also called billabongs) characterizing the rivers in that region.

They have a tendency of to move upstream to avoid being stranded in the lower river which tends to dry up in dry season.

The crawdad-dies can be grown in recirculating water systems (tanks) without adversely affecting the water quality. How to raise crayfish. However, when they are reared in smaller containers they will exhibit a slower growth rate; hence bigger containers will have a significant growth rate.

Ensure that the site location and preparation of ponds will cater for the needs of the crayfish; the ponds should be situated in flat, open areas and the soil should be heavy clay.

The heavy clay soil is necessary to maintain the integrity of mudbugs burrows, so sandy soil is not recommended.

Pond Types For Crayfish

In some countries, crayfish aqua farming is done directly at the ocean while for some individuals preferring to start out in a small scale gradually upgrading their farming scale.

It is imperative to know the type of pond to use when starting out in crayfish aqua farming and these being;

• Wooded ponds- they are built in forested areas on heavy clay soil though the production is limited by the inability to manage water efficiency.
• Semi-wooded ponds- this type reduces tree density and generally improving crawfish habitat.
• Marsh ponds – are constructed in coastal areas and have a low yield in crawfish because the high concentration of organic matter in the soil reduces water quality and decrease production.
• Open ponds (rice field and permanent ponds) – the rice field pond for crawfish are productive as they are located in fertile soil, quality water supply, often have baffle levees and recirculation capabilities; while the permanent ponds are constructed solely for the purpose of cultivating crawfish, making it possible to harvest crawfish for a month or two longer because there is no conflict with planting, draining and harvesting other crops.

Water Quality (Including Supply)

Good quality water management requires that the crawfish ponds be properly designed and constructed making them has a dependable supply of surface or subsurface fresh water.

The water should have sufficient concentration of dissolved oxygen which will aid in the growth of crayfish because low concentration of oxygen will result in high mortality and encouraging diseases due to not growing and feeding well. It is advisable to always maintain the oxygen levels in the water.

The quality and quantity are the most limiting factors in aqua farming; be sure you have the satisfactory water quality maintenance especially during the flooding periods due warm weather. A properly managed open crawfish pond will generally require consistent water exchange per production season.

Reproduction

Most crayfish reproduce sexually, usually in open water during late spring or early summer. The female stores the male’s sperm until her eggs are ready for fer­tilization.

Incredibly, female crayfish can produce 200 to 800 fertilized eggs per brood, and because of this, even one female released into a body of water can cause an infestation if she is carrying viable sperm.

After fertilization and release, the eggs stay attached to the female’s swimmerets, which are on the underside of her tail segment.

Eggs typically incubate from just a few weeks to months, after which the hatchlings remain attached to the swimmerets for several more weeks. The hatchlings usually become detached in open water and continue to molt through their juvenile stage.

It takes three months to several years for the hatch­lings to reach sexual maturity, depending on the species. Once sexual maturity is reached, crayfish grow more slowly and take on the distinctive colour patterns typically associated with their species.

Crayfish have a broad range of life spans, with some species living only two years and other species, such as the signal crayfish, living as long as 20 years.