ANGUILLICOLA-CRASSUS, A RECENTLY INTRODUC ED AGGRESSIVE COLONIZER OF EUROPEAN EEL STOCKS

Conveyed from the Far East Asia, the nematode parasite Anguillicola cr assus has been introduced into Europe and has successfully colonized m ost European countries throughout the 1980's. Although influenced by c olonization patterns, parasite populations tend towards maximal preval ence and predictable mean intensities in most freshwater European bioc enosis. These data indicate that this parasite possesses several attri butes of an aggressive colonizer such as high dispersion ability, leng th of the free stage survival, high fecundity and reproductive rate, r eceptivity of intermediate and paratenic hosts. The biological mechani sms of the colonization of Anguillicola crassus and the parasite impac t on the definitive host populations are reviewed.