Thelohanellus nikolskii infection of the common carp (Cyprinus carpio L.) has been a common parasitosis in the Central European fish farms since the first detection of the parasite about 20 years ago. This parasite, introduced from the Far East, causes intensive infection on the fins of fingerlings of the carp subspecies cultured in Europe (European carp, Cyprinus carpio carpio). This infection...

A comparative analysis of parasite species richness was performed across 53 species of fish from the floodplain of the upper Paraná River, Brazil. Values of catch per unit effort, CPUE (number of individuals of a given fish species captured per 1000 m(2) of net during 24 h) were used as a rough measure of population density for each fish species in order to test its influence on endoparasite sp...

Spironucleus salmonicida causes systemic infections in salmonid fish. It belongs to the group diplomonads, binucleated heterotrophic flagellates adapted to micro-aerobic environments. Recently we identified energy-producing hydrogenosomes in S. salmonicida. Here we present a genome analysis of the fish parasite with a focus on the comparison to the more studied diplomonad Giardia intestinalis. ...

Fish acquire immunity against the ciliated protozoan parasite Ichthyophthirius multifiliis following sublethal infection. The immune response includes the elaboration of humoral antibodies against a class of abundant surface membrane proteins referred to as immobilization antigens (i-antigens). Antibodies against these proteins immobilize the parasite in vitro, suggesting a potential role for t...

In January 2020, a mortality event was documented in endangered Pallid Sturgeon (Scaphirhynchus albus) at the Neosho National Fish Hatchery (Neosho, MO, USA). Moribund fish appeared emaciated, with hemorrhages on fins and rostrums. Mortality steadily increased, prompting an investigation into cause. No viral or bacterial pathogens were detected; however, high number of novel Gyrodactylus sp. id...

Species identification is crucial for studies of parasite diversity, yet most surveys include taxa identified only to genus or family level. Using a large dataset comprising 950 surveys of helminth communities from 650 different species of fish, bird and mammal hosts, we investigated what determines the level of taxonomic resolution achieved. Identification of all helminths down to species leve...

Interspecific interaction may lead to species exclusion but there are several ways in which species can coexist. One way is by reducing the overall intensity of competition via aggregated utilisation of fragmented resources. Known as the 'aggregation model of coexistence', this system assumes saturation and an equilibrium number of species per community. In this study we tested the effects of i...

The goals of this paper were to investigate phylogenetic and evolutionary patterns of cichlid fish from West Africa and their Cichlidogyrus and Scutogyrus monogenean parasites, to uncover the presence of host-parasite cospeciation and to assess the level of morphological adaptation in parasites. This required the following steps, each one representing specific objectives of this paper: (1) to b...

We present a model for a host-parasite system in which parasites affect the economy of fish farming. The fish is sea-bass, Dicentrarchus labrax, and the parasite is a helminthic ectoparasite, Diplectanum aequans, which adheres to the branchiae of the host and, when present in sufficient number, kill it by suffocation. The improved model incorporates two important features observed in the fish f...