Cryptic species complexes are common among parasites, which tend to have large populations and are subject to rapid evolution. Such complexes may arise through host-parasite co-evolution and/or host switching. For parasites that reproduce directly on their host, there might be increased opportunities for sympatric speciation, either by exploiting different hosts or different micro-habitats with...

The present study reports on the main parasites found in mullet (Mugil platanus) and their prevalence throughout the year on Uruguayan coasts of the River Plate. The following parasites were found: Ichthyobodo necator, Trichodina sp., Scyphidia sp, Gyrodactylus sp., Dactylogyrus sp., Metamicrocotyla sp., Dicrogaster sp., Phagicola sp. and “Scolex polymorphus”. The viability of mullet (Mugil pla...

Recirculation systems create unique environments for fish culture. Opportunistic microorganisms may cause disease due to favorable conditions occurring in recirculation systems. The biofilters used may become reservoirs of infectious microorganisms. Stressful conditions such as suspended solids in culture tanks and high rearing densities may contribute to disease outbreaks. Additionally, noninf...

The monogenean ectoparasite genera Dactylogyrus and Gyrodactylus are hyperdiverse, and yet monogenean communities infecting freshwater fish in the northern Holarctic are variable and often impoverished. This is a result of extinctions during periods of glaciation when the host fishes experienced range contraction. Fish species recolonised northern Europe by one of three routes; stenohaline fish...

Gyrodactylus salaris Malmberg, 1957 is a major pathogen of wild Salmo salar L. parr populations in Norway, and its delimitation from non-pathogenic species is important. The present study was undertaken to test the power of chaetotaxy to differentiate between three populations belonging to both the same and different clades (as stated by mtDNA) of G. salaris, in addition to three different spec...

We present an in silico approach for the reconstruction of complete mitochondrial genomes of non-model organisms directly from next-generation sequencing (NGS) data-mitochondrial baiting and iterative mapping (MITObim). The method is straightforward even if only (i) distantly related mitochondrial genomes or (ii) mitochondrial barcode sequences are available as starting-reference sequences or s...

Gyrodactylus thymalli Zitnan, 1960 and G. salaris Malmberg, 1957 have an indistinguishable ribosomal internal transcribed spacer (ITS) DNA sequence, but exhibit surprisingly high levels of intra- and interspecific sequence variation of the mitochondrial cytochrome oxidase I (CO1) gene. To test whether different populations of these reportedly very similar species could be discriminated using mo...

The major histocompatibility complex (MHC) is crucial to the adaptive immune response of vertebrates and is among the most polymorphic gene families known. Its high diversity is usually attributed to selection imposed by fast-evolving pathogens. Pathogens are thought to evolve to escape recognition by common immune alleles, and, hence, novel MHC alleles, introduced through mutation, recombinati...