A review of astaciculture: freshwater crayfish farming

Abstract

The farming of freshwater crayfish (astaciculture) is mainly carried out in the southem states of the USA, and in Australia and Europe. Production levels Vary with climate but are in the region of 40000 to 60000 tonnes per annum. In addition, at least an equivalent amounts is harvested from the wild, particularly in North Amenca, China, Australia, Kenya, Turkey and Europe. Crayfish farming is usually cithcr of an extensive (ranching) or semi-intensive nature, intensive methods being infrequent, except for the rearing of juveniles for stocking (or restocking of natural waters depleted of crayfish). As crayfish do not have larvae and are polytrophic, they are relatively easy to rear, although fecundity is much lower when compared with other cultured crustaceans. At least 85% of world production is based on the red swamp crayfish, Procamharus clarkii, mainly from Louisiana and other southern USA states, but also from China, Kenya and Spain, where it has been introduced. In Australia, three species are of aquacultural importance, the yabbie, Cherax destructor; the marron, C. tenuimanus; and the red claw, C. quadricarinatus. Some very large production units have been built but none have lived up to their promise. The red claw is thought to have considerable aquacultural potential, but, being a tropical species, needs warm water for good growth. In Europe, the only endemic species cultured to any extent is the noble crayfish, Astacus astacus, mainly as juveniles for restocking. It fetches a higher pnce than other crayfish. The North American signal crayfish, Pacifastacus leniusculus, has been introduced to most European countries, but farmed production is relatively low. About 98% of crayfish consumed in Europe come from extensive systems or the wild harvest. European crayfish markets were upset by the collapse of the Turkish crayfishery (based on Astacus leptoductylus) due to overfishing and disease in the mid-1980s. The environmental impact of crayfish farrning is most noticeable in Europe. Crayfish plague, introduced from North America last century, haî devastated populations of the native species in many countries. 1ts spread has been exasperated by the translocation of foreign crayfish (and probably by fish) for aquacultural purposes. In addition, introduced crayfish frequently escape into the wild and form large populations, often in direct competition with native species. Burrowing and prolific species, such as P. clarkii, can also do considerable environmental damage.

A Comparison of Survival and Growth in Juvenile Astacus Leptodactylus (Esch.) and Pacifastacus Leniusculus (Dana) Under Controlled Conditions

“…In breeding ponds, given favourable conditions, the chances of surviving the first year of life are high (45-90%) for both signal crayfish (KRZYWOSZ, 1994;KOZAK et al, 1998) and narrow-clawed crayfish (TCHERKASHINA, 1977). Most authors therefore recommend rearing crayfish in small ponds (CUKERZIS, 1989;HOLDICH, 1993HOLDICH, , 2002ACKEFORS and LINDQVIST, 1994;ACKEFORS, 1998) with initial stocking densities of juveniles stage 2 of no more than 100 individuals per square metre.…”

“…As a result, populations of noble crayfish and narrow-clawed crayfish are numerous only in SE Poland (KRZYWOSZ, 1994). Since the market value of native crayfish in Europe is higher than the one of imported species, it is more profitable to develop the farming of the former (HOLDICH, 1993), and many crayfish farmers in Europe have done precisely that (ACKEFORS, 1998). Crayfish farming also plays a significant role in the active protection of native species for restocking programmes (ACKEFORS and LINDQVIST, 1994;ACKEFORS, 1998;MASTYŃSKI and ANDRZEJEWSKI, 2001;SKURDAL and TAUGBØL, 2002;CARRAL et al, 2003;ŚMIETANA et.…”

Distribution of Crayfish in Europe and Some Adjoining Countries

“…Turkey was a major supplier of crayfish to West European markets but stocks were badly hit by crayfish plague in the mid-1980s (BARAN and SOYLU, 1989;HOLDICH, 1993;ALDERMAN, 1996). NICS appear to not to have become established yet, and there has been a modest recovery of stocks in some previously devastated lakes south of Bursa, but other lakes that had been the highest producers have yet to recover (P. BAGOT, pers.…”

Towards a sustainable human use of freshwater crayfish (Crustacea, Decapoda, Astacidea)

“…The British Crayfish Marketing Association (BCMA) was set up which helped maintain prices and quality, and marketed crayfish for its members. However, despite many predictions being made about the likely profits, they are still an unfulfilled promise: the BCMA did not survive for long as independent crayfish growers undercut their prices, and most of the exports are now being made with crayfish harvested from natural waters (Holdich, 1993). In Italy, the red swamp crayfish has been exploited in the Massaciuccoli Lake (Tuscany) since the 1990s, but this industry has met with very little success due to low demand of crayfish in the Italian markets (Barbaresi and Gherardi, 2000).…”

“…Crayfish are good aquacultural organisms as some species reproduce readily in captivity (Holdich, 1993). They are also nearly unique amongst crustacean decapods in not having larvae (Holdich, 1993): shrimps and prawns typically have 11−12 larval stages which have different dietary requirements from the juveniles and adults, but what hatches out from the crayfish egg already resembles a crayfish and by the time they leave the mother they can feed on most animal and plant foods. Consequently, it is relatively much easier to culture crayfish than prawns and shrimps.…”