Question: How does sexual ornamentation relate to parasite infection, host immune response and somatic condition status in male fish? Hypotheses: Zahavi’s (1975) handicap hypothesis proposes that producing secondary sexual traits represents a considerable handicap for males. Additionally, Hamilton and Zuk (1982) proposed that the expression of secondary sexual traits reveals a genetic resistanc...

the studies of parasitology was performed on freshwater in farm ponds in isfahan province during the years of 2006- 2008 and in total were fished 150 fish from farm ponds of freshwater fish and dual purpose of agriculture of three regions in isfahan. the fish were 65 cyprinus carpio, 40 hypophthalmichthys molitrix and 45 ctenopharyngodon idella. the samples were taken to laboratory alive and af...

Two new species of Gyrodactylus (Gyrodactylidae) are described from Corydoras paleatus (Jenyns) and Corydoras ehrhardti Steindachner (Callichthyidae) of Rio Piraquara, Municipality of Piraquara, near Curitiba, Paraná, Brazil: Gyrodactylus anisopharynx sp. n. and Gyrodactylus samirae sp. n. These species are unique among the known Neotropical species of Gyrodactylus by the combination of several...

  The present studywas carried out to survey ectoparasites fauna of gold fish (Carassius auratus) in Mazandaran province (Iran) from April 2009 to March 2010. A total of 200 samples were obtained from 10 ornamental fish supply centers and transferred alive to the laboratory. In this study, the following ectoparasites were isolated: Ichthyophthirius multifillis , Trichodina spp., Gyrodactyl...

Predation and parasitism are two of the most important sources of mortality in nature. By forming groups, individuals can gain protection against predators but may increase their risk of being infected with contagious parasites. Animals might resolve this conflict by forming mixed-species groups thereby reducing the costs associated with parasites through a relative decrease in available hosts....

Thirty three Gyrodactylus spp have been found on the gills and body surface of both wild and farmed freshwater fishes in Iran. Among them nine species have been identified up to the species level, which are new locality records. The identification of the others, mainly belong to endemic wild freshwater fishes, need further studies. Among the known species, Gyrodactylus derjavini (Mikhailov, 197...

Thirty three Gyrodactylus spp have been found on the gills and body surface of both wild and farmed freshwater fishes in Iran. Among them nine species have been identified up to the species level, which are new locality records. The identification of the others, mainly belong to endemic wild freshwater fishes, need further studies. Among the known species, Gyrodactylus derjavini (Mikhailov, 197...

Ectoparasites which often attack tilapia include Trichodina sp., Dactylogyrus spp., Gyrodactylus and Epistylis spp. This research aims to determine the types, prevalence, intensity of ectoparasites found on (Oreochromis niloticus) in floating net cages Batanghari River, Jambi. The was conducted from February through March 2020. A survey method is carried out direct sampling at study site identi...

Gyrodactylus mediotorus n. sp. is described from the body, fins, and buccal cavity of the spottail shiner, Notropis hudsonius (Cyprinidae) from the St. Lawrence River, Quebec, Canada. Gyrodactylus mediotorus n. sp. is the first species of Gyrodactylus Nordmann, 1832 described from N. hudsonius and is characterized by large hamuli, large medial process of the ventral bar, narrow linguiform ventr...