The Effects of Plague Disease on Crayfish Stocks in Some Lakes of Turkey

Crayfish was an important shellfish product of turkey, exported to europe before break out of the crayfish plague in çivril and eğirdir lakes. according to the statistical records 7936 tons of crayfish were produced totally from the lakes of turkey in 1984. but in 1985, from çivril and eğirdir and after that the other lakes crayfish production dramatically fell down to neglicable amount for the reason of this disease. die and tuik records and also the later studies on these lakes crayfish showed that aphanomyces astaci did not perish in the fresh and brackish lakes and caused the later outbreak of the plague disease in the favorable conditions. in 1984, a high mortality of crayfish occurred first in lake çivril, than in lake eğirdir and later in the other lakes of the lakes region namely karataş, beyşehir and destroyed whole crayfish populations in these lakes very quickly. infected crayfish exhibited definite symptoms of crayfish plague diseases such as slow and uncoordinated limb movements, paralyzed extremities, loss of legs and claws, destruction of the cuticular surfaces of the affected areas especially at the anal region and the articular membranes of the walking legs or on their chitinous carapace or abdomen segments. microscopic observation of aseptate hyphae both in fresh preparation or sabouraud-glucose agar isolates were identified as a. astaci as a etiologic agent. some hyphae in the same fresh preparation or agar isolates that microscopically observed were septate with ovoid and gondola shaped conidiospores were diagnosed as fusarium sp. and considered to be secondary infection in the most crayfish