During a survey of the parasites of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula the following species of monogeneans were found on cichlid, pimelodid, characid and poeciliid fishes: Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther) (type host), Cichlasoma friedrichsthali (Heckel), Cichlasoma octofasciatum (R...

Active Shape Models (ASM) are applied to the attachment hooks of several species of Gyrodactylus, including the notifiable pathogen G. salaris, to assign each species to its true species type. ASM is used as a feature extraction tool to select information from hook images that can be used as input data into trained classifiers. Linear (i.e. LDA and K-NN) and non-linear (i.e. MLP and SVM) models...

Parasites with high host specificity maximally depend on their hosts, which should increase the likelihood of coevolution. However, coevolution requires reciprocal selection exerted by the host and the parasite, and thus a considerable level of parasite virulence. In species of the monogenean ectoparasite genus Gyrodactylus consecutive generations are confronted with a single host, which may co...

Morphometric analyses are used to evaluate the taxonomic status of two sympatric variants of Gyrodactylus anisopharynx Popazoglo et Boeger, 2000 (forma "large-pharynx" and forma "small-pharynx"). The parasites were collected from the Piraquara River and the Miringuava River, State of Paraná, Brazil, between February 2005 and May 2006. A total of 132 parasites were measured from two hosts, Coryd...

Hosts and parasites are in a perpetual co-evolutionary "arms race". Due to their short generation time and large reproductive output, parasites are commonly believed to be ahead in this race, although increasing evidence exists that parasites are not always ahead in the arms race - in part owing to evolutionary lineage and recent ecological history. We assess local adaptation of hosts and paras...

The present study addresses the effect of varying temperature and host species on the size and shape of the opisthaptoral hard-parts in isogenic strains of Gyrodactylus salaris and G. thymalli. Variation in shape was examined using geometric morphometrics. Since the opisthaptoral hard-parts of Gyrodactylus have few specific landmarks, their shape information mostly being represented by outlines...

The present work was conducted to isolate and identify different parasites from Indian Major Carp (IMC) Catla catla. During the study period the severity of infection and Parasitic Frequency Index (PFI, %) were also estimated in terms of months, seasons and length groups of fishes. For the investigative purpose different districts of West Bengal were selected considering the potential of fisher...