The susceptibility of 2 strains of rainbow trout Oncorhynchus mykiss, 1 from North America (TL) and 1 from Germany (GR), to Myxobolus cerebralis (the cause of salmonid whirling disease) was assessed following exposure to the infectious stages (triactinomyxons). Two laboratory experiments were conducted with age-matched rainbow trout of each strain. At the beginning of the study, the 2 trout str...

Gibel carp Carassius auratus gibelio (Bloch), a commercially important freshwater-cultured fish in China, is threatened by myxosporeans, particularly Thelohanellus wuhanensis, Myxobolus honghuensis, M. wulii and M. turpisrotundus. Here, we developed a multiplex PCR assay for simultaneous detection of these 4 myxosporeans. The specific primers for each species were designed based on the 28S rDNA...

Histopathological changes in gills of a native fish Capoeta aculeata, naturally-infected with parasites were studied. The specimens (15.5 to 22.8 cm) were collected from Choghakhor lagoon in West Iran. 35 (11%) of the total 318 studied fishes were infected with gill parasites. Overall, six protozoan and metazoan parasite species were collected from fishes including Ichthyophthirius multifiliis,...

Myxobolus cerebralis, the myxosporean parasite-causing salmonid whirling disease, was first reported among rainbow trout (Oncorhynchus mykiss) in Germany in 1903. The parasite was reported for the first time in North America in 1958 among hatchery-reared trout in the eastern USA, presumably arriving with frozen trout shipments from Europe. A comparison of 18S and ITS-1 ribosomal DNA sequences w...

Abstract Myxosporidiosis is an infectious disease caused by myxozoans of the Phylum Cnidaria, Class Myxosporea, and Order Bivalvulida, considered a common parasite in fresh saltwater fishes that parasitize many organs, especially gills. In present study, 49 specimens belonging to eight genera: Tetragonopterus, Leporinus, Myleus, Pirinampus, Rhapiodon, Pygocentrus, Ageneiosus, Serrasalmus were c...

Oligochaetes, triactinomyxons (TAMs), and age-0 trout were sampled in the upper Cache la Poudre River, Colorado, to determine the distribution of Myxobolus cerebralis during 1997 and 1998. Densities of the intermediate host, the oligochaete Tubifex tubifex, were 3.5 orders of magnitude higher in the M. cerebralis-infected Poudre Rearing Unit (PRU) trout rearing ponds than at any of the river sa...

This article answers three questions of J. Almeida. Using combinatorial, algebraic and topological methods, we compute joins involving the pseudovariety of finite groups, the pseudovariety of semigroups in which each idempotent is a right zero and the pseudovariety generated by monoids M such that each idempotent of M\{1} is a left zero.

A nested polymerase chain reaction (PCR) assay was used to detect early stages of Myxobolus cerebralis in caudal and adipose fin samples from rainbow trout (RT). To determine sensitivity, groups of 10 RT were exposed to 2,000 M. cerebralis triactinomyxons/fish for 1 hour at 15 degrees C and subsequently moved to clean recirculating water. Fish were held for 2 and 6 hours and 1, 2, 3, 5, 7, 10, ...

The ascaridoid nematodes Dujardinascaris madagascariensis Chabaud & Caballero, 1966, Dujardinascaris dujardini (Travassos, 1920), Gedoelstascaris vandenbrandeni (Baylis, 1929) Sprent, 1978 and Multicaecum agile (Wedl, 1861) Baylis, 1923 were recovered from the stomach contents of Crocodylus niloticus Laurenti, 1768 from the Okavango River, Botswana, together with Eustrongylides sp., a dioctophy...