ABSTRACT
Wild European catfish (Silurus Glanis) is distributed from the south of Sweden to the Alps (Morat, Neuchatel, Bienne and Constance lakes) and eastwards to the Black and Caspian Seas. European catfish is a commercially important species in eastEuropean countries, but its rearing is now being developed in western countries. European catfish is a carnivorous fish reared in outdoor ponds. Males become sexually mature at 2-3 years old, females at 3-5 years old. Breeding occurs in the spring (MayJuly), when water temperature reaches 20°C. Sperm cryopreservation has been very little documented in this species [1,2], contrarily to other catfish species such as African catfish Clarias gariepinus [3-11], Heterobranchus longifilis [12], channel catfish Ictalurus punctatus [13-15], or blue catfish Ictalurus furcatus [16]. Males from European catfish are oligospermic, and sperm is always contaminated and activated by urine during stripping [17]. As a consequence, testicular sperm is often preferred to sperm obtained after stripping of the males. The present paper describes a method for cryopreservation of sperm obtained from testis of mature European catfish. The reader is referred to the very informative papers of Legendre et al. [18] and Linhart et al. [19] for thorough data on artificial reproduction of European catfish, since only information related to sperm cryopreservation will be given here.
