Helminth parasites of finfish commercial aquaculture in Latin America

Abstract

Latin America has tripled production by aquaculture up to 78 million tonnes in the past 20 years. However, one of the problems that aquaculture is facing is the presence of helminth parasites and the diseases caused by them in the region. In this review we have collected all the available information on helminths affecting commercial aquaculture in Latin America and the Caribbean (LAC), emphasizing those causing serious economic losses. Monogeneans are by far the most common and aggressive parasites affecting farmed fish in LAC. They have been recognized as serious pathogens in intensive fish culture because they reach high levels of infection rapidly, and can infect other phylogenetically related fish species. The next most important group comprises the larval stages of digeneans (metacercariae) such as Diplostomum sp. and Centrocestus formosanus, which cause serious damage to farmed fish. Since LAC aquaculture has been based mainly on exotic species (tilapia, salmon, trout and carp), most of their parasites have been brought into the region together with the fish for aquaculture. Recently, one of us (A.I.P.-T.) has suggested that monogeneans, which have generally been considered to be harmless, can produce serious effects on the growth of cultured Nile tilapia. Therefore, the introduction of fish together with their 'harmless' parasites into new sites, regions or countries in LAC should be considered a breakdown of biosecurity in those countries involved. Therefore, the application of quarantine procedures and preventive therapeutic treatments should be considered before allowing these introductions into a country.

The digestive tube of Piaractus brachypomus: gross morphology, histology/histochemistry of the mucosal layer and the effects of parasitism by Neoechinorhynchus sp.

“…Among parasites, helminths are frequently neglected as disease‐causing agents in fishes. However, parasitic helminth propagation and establishment may have harmful consequences to the health of organisms when these parasites are present in high numbers within a population that is farmed using poor management practices and insufficient biosafety plans (Soler‐Jiménez et al, ). One important endohelminth group that parasitises fishes is the hook‐headed worm phylum Acanthocephala (Kennedy, ; Taraschewski, ).…”

Current knowledge on use of essential oils as alternative treatment against fish parasites

“…2), which are helminths ectoparasites that cause great economic losses in fish farming due to epizootics (Steverding et al, 2005;Soler-Jiménez et al, 2017). Other parasitic helminth species has been neglected as causative agents of farmed fish diseases, because fish farmers have often believed that these parasites are harmless.…”

“…However, a number of both external and internal factors affect fish production, and these problems unequivocally include parasitosis (Soler-Jiménez et al, 2017). High stocking density and the handling practices used in fish farming are among the factors involved.…”

“…Moreover, freshwater fish farming is an excellent alternative for minimizing the intense wild fish exploitation that occurs in diverse regions of the planet. In addition, current growth of the global population has been leading to additional expansion of intensive fish production, because of demand for food (Engle et al, 2017;Soler-Jiménez et al, 2017).…”

“…High stocking density and the handling practices used in fish farming are among the factors involved. The increasing prevalence of fish farming has led to increased occurrence of parasitic diseases that compromise the sustainability of the fish farming industry (Soler-Jiménez et al, 2017;Soares et al, 2017a, b). The diseases cause mortality, slow growth of fish and reduction of feed conversion rates, and they decrease the commercial value of fish (Bastos Gomes et al, 2017).…”