DAO 43:217-223 (2000)  -  doi:10.3354/dao043217

Neoparamoeba Page, 1987: light and electron microscopic observations on six strains of different origin

I. Dyková1,*, A. Figueras2, Z. Peric3

1Institute of Parasitology, Academy of Sciences of the Czech Republic, Branicovská 31, 370 05 Ceské Budejovice, Czech Republic
2Concejo Superior de Investigaciones Cientificas, Instituto de Investigaciones Marinas, Eduardo Cabello 6, 36208 Vigo, Spain
3Ministry of Agriculture and Fisheries, National Aquaculture Centre, Malta
*E-mail:

ABSTRACT: Although amoebic gill disease (AGD) has emerged as one of the most severe health problems in the fish industry, proof of the identity of AGD agents from various localities is still missing. Six strains of amoebae designated until recently as Paramoeba species (the agents of AGD) were studied in cultures by light and electron microscopy. Although they were isolated from gills of different hosts (Dicentrarchus labrax and Scophthalmus maximus) and from distant localities, their morphology was identical. The strains differed from Paramoeba eilhardi, the type species of the genus, in that they lacked the boat-shaped microscales on the cell surface but could be safely identified as belonging to the genus Neoparamoeba Page, 1987. Transmission electron microscopy revealed the presence of a symbiotic organism, Perkinsiella amoebae Hollande, 1980, in all strains under study. The only difference among the strains examined was found in the size of trophozoites, which could be attributed to the different origins of the strains, but until more refined diagnostic methods are available, in addition to N. pemaquidensis, the closely related species N. aestuarina also has to be taken into consideration as the agent of AGD.


KEY WORDS: Paramoeba · Neoparamoeba · Etiology of AGD · Mariculture


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