ABSTRACT
A total of 18 Neoparamoeba strains were characterized both morphologically and using the SSU rRNA gene sequences as molecular markers. Nine were isolated from gills of farmed Atlantic salmon, Salmo salar L., six from sediments sampled in areas of sea-cage farms and three from net material of sea-cages. The newly obtained sequences extended substantially the dataset of Neoparamoeba strains available for phylogenetic analyses, which were used to infer taxonomic relatedness among 32 strains morphologically assigned to this genus. In addition to the N. pemaquidensis and N. aestuarina clades, phylogenetic analyses clearly distinguished a third clade with sequences from six strains. Members of this clade are characterized as representatives of a new species, N. branchiphila n. sp. The diagnostic primers for the identification of this species are introduced.
Subject(s)
Gills/microbiology , Lobosea/genetics , Lobosea/ultrastructure , Phylogeny , Salmo salar/microbiology , Analysis of Variance , Animals , Base Sequence , Cluster Analysis , DNA Primers , Likelihood Functions , Microscopy, Electron, Transmission , Models, Genetic , Molecular Sequence Data , Principal Component Analysis , RNA, Ribosomal/genetics , Sequence Analysis, DNA , Species SpecificityABSTRACT
Four strains of non-encysting amoebae were isolated from organs of freshwater fishes and characterized using light and electron microscope. Morphology of three clonal strains was consistent with amoebae which had already been described from water habitats. Two strains, one isolated from kidney tissue of common goldfish, Carassius auratus (Linnaeus, 1758), and the second one from brain of chub, Leuciscus cephalus Linnaeus, 1758, were identified with Vannella platypodia (Gläser, 1912) Page, 1976. Both strains were identical, except for the length of glycostyles. The strain isolated from the liver of perch, Perca fluviatilis (Linnaeus, 1758), was assigned to the genus Vexillifera Schaeffer, 1926 as Vexillifera expectata sp. n. The taxonomic position of the fourth non-encysting strain could not be safely established, although it shares some trophic cell structures with protostelids (Protostelia, Eumycetozoea). We present its detailed description here also to demonstrate that amoeba stages of this type of organisms are capable to infect fishes.
Subject(s)
Amoebida/classification , Fishes/parasitology , Amoebida/isolation & purification , Amoebida/ultrastructure , Animals , Brain/parasitology , Czech Republic , Fresh Water , Kidney/parasitology , Liver/parasitology , Spleen/parasitologyABSTRACT
A scale-bearing amoeba isolated from gills and other organs of perch Perca fluviatilis Linnaeus, 1758 was identified as Cochliopodium minus Page, 1976. This assignment was suggested by light microscopy and confirmed by ultrastructural study of both the strain isolated from perch and the environmental strain of C. minus (CCAP 1537/1A) serving as a control. This has been the first electron-microscopic definition of C. minus and, in addition, the first identification of an amoeba with a theca-like cover found to infect fish. The ability of the fish strain of C. minus to colonize gills and also internal body organs was proved experimentally.
