The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla ...

Mormyrogyrodactylus gemini gen. et sp. n. (Gyrodactylidea: Gyrodactylidae), a viviparous monogenean is described from the skin and fins of Marcusenius macrolepidotus (Peters) from South Africa. This new genus is unique in having a large cup-shaped cirrus armed with one large needle-like spine and numerous small hair-like spinelets. A peduncular bar is present. The haptor is clearly demarcated f...

Several environmental parameters may influence biological processes of several aquatic invertebrates, such as the Monogenea. Current analysis investigates oviposition, hatching success and infestation of Aphanoblastella mastigatus, a parasite of the silver catfish Rhamdia quelen at different temperatures (~ 24 and 28 °C) and salinity (by adding sodium chloride to water, at concentrations 0, 5 a...

Gyrodactylus teuchis is a widespread parasite of wild and farmed salmonids throughout Europe. It has been frequently confused with the notifiable pathogen G. salaris, to which it bears a striking morphological similarity. The species is frequently referred to as 'cryptic', and diagnoses are primarily based on molecular evidence. We provide the first comprehensive re-description of G. teuchis fr...

The monogenean ectoparasite, Gyrodactylus salaris Malmberg, 1957, has had a devastating effect on wild Atlantic salmon (Salmo salar) since its introduction to Norway in the mid-1970s. In Lake Pålsbufjorden, southern Norway, upstream of the stretches of the River Numedalslågen with anadromous Atlantic salmon, a resident Arctic charr (Salvelinus alpinus) population has been reported to be infecte...

We present the complete mitochondrial (mt) genome of Gyrodactylus thymalli, a monogenean ectoparasite on grayling (Thymallus thymallus). The circular genome is 14788 bp in size and includes all 35 genes recognized from other flatworm mt genomes. The overall A+T content of the mt genome is 62.8%. Twenty regions of non-coding DNA ranging from 1 to 111 bp in length were identified in addition to 2...

In this study, we clarify the taxonomic status of Allencotyla pricei based on a re-examination of paratypes and voucher specimens. Four important characters are added to previous descriptions: the vagina is ventral; the cirrus is absent; the eggs are fusiform and have two polar filaments (one about 3.5 times longer than the other); and, there are two flat sclerites at each side of the dorsal tr...

Aristocleidus mexicanus n. sp. and Aristocleidus lacantuni n. sp. are described from the gills of the Mexican mojarra Eugerres mexicanus (Gerreidae, Perciformes) from the Rio Lacantún basin, Chiapas State, Mexico. These new species differ from previously described congeneric species in the characteristics of several structures, including: (a) ventral anchors, with differences in length (i.e. 46...

Gyrodactylus salaris is a serious pest of wild pre-smolt Atlantic salmon (Salmo salar) in Norway. The closely related G. thymalli, originally described from grayling (Thymallus thymallus), is assumed harmless to both grayling and salmon. The 2 species are difficult to distinguish using traditional, morphometric methods or molecular approaches. The aim of this study was to explore whether there ...

A new species of dactylogyrid monogenean, Apedunculata discoidea gen. n., sp. n. is described and illustrated from the gills of the freshwater fish Prochilodus lineatus (Valenciennes, 1837) in pisciculture ponds from Pirassununga, São Paulo, Brazil. Diagnostic characters of the new genus and species are: 1) vagina dextrolateral slightly sclerotised, opening anteriorly at level of copulatory com...