Lerneosis en peces silvestres y cultivados del centro de Argentina

Abstract

The genus Lernaea (Crustacea) comprises ectoparasitic copepods with worldwide distribution. Lernaea causes damage in the skin of fishes and facilitate secondary infections. In the present work, several outbreaks of lernaeosis in the central region of Argentina, the ichthyofauna involved and their main epidemiological features were assessed.
In 41 cases from 1993 to 2006, 14 species from five provinces were affected. The fishes were either cultured or wild and ornamental or edible. The parasite was determined as Lernaea cyprinacea L. 1758. The intensity of infection was correlated with water temperature (rs= 0.71, P< 0.05). The prevalence was variable with maximum between 80.9 to 100% in Oligosarcus jenynsii and Cyprinus carpio, respectively. Odontesthes bonariensis, one of the most important continental fishing species in Argentina, was the most affected in the wild group (53.6% of the total outbreaks). However, the intensity of infection was low to median (≤ 7 parasites per host) in this species. In three situations analized, there were no significat differences in body condition of O. bonariensis between parasited and non-parasited (P> 0.05). Among the ornamental species, Carassius auratus had the most prevalence. In several outbreaks, L. cyprinacea was a part of a multiaetiological complex causing fish mortalities. Taking into account the present observations, the regionality of the lernaeosis and its consistent increasing rate, preventive measures should be established in order to diminish the risk of dispersion due to commercial traffic of fishes.