Article

Can myxosporean parasites compromise fish and amphibian reproduction?

Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas, Torre de la Sal s/n, 12595 Ribera de Cabanes, Castellón, Spain.
Proceedings of the Royal Society B: Biological Sciences (impact factor: 5.41). 06/2009; 276(1669):2861-70. DOI:10.1098/rspb.2009.0368 pp.2861-70
Source: PubMed

ABSTRACT Research into fish and amphibian reproduction has increased exponentially in recent years owing to the expansion of the aquaculture industry, the need to recover fishery populations, the impact of endocrine disruptors on the aquatic environment and the global decline of amphibian populations. This review focuses on a group of parasites, the Myxozoa, that affect fish and amphibian reproduction. Lists of the myxosporeans that specifically infect gonads are provided. Most of these are parasitic of freshwater hosts, and most amphibian cases are reported from testes. Sex specificity and sex reversal are discussed in relation to gonadal parasitism. The immune response of the fish to the infection is described, and the contribution of the immunoprivilege of gonads to host invasion is emphasized. The pathological effect of these parasites can be significant, especially in aquacultured broodstocks, on some occasions, leading to parasitic castration. Although myxosporean parasites are currently not very frequent in gonads, their impact could increase in the future owing to the transactions in the global market. Their easy release into the aquatic environment with spawning could make their spreading even more feasible. In the absence of commercial drugs or vaccines to treat and prevent these infections, there is an urgent need to develop specific, rapid and reliable diagnostic tools to control and manage animal movements. In addition, much effort is still to be made on deciphering the life cycle of these organisms, their invasion strategies and their immune evasion mechanisms.

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Keywords

affect fish
 
amphibian cases
 
amphibian populations
 
amphibian reproduction
 
aquaculture industry
 
aquacultured broodstocks
 
aquatic environment
 
commercial drugs
 
endocrine disruptors
 
fishery populations
 
freshwater hosts
 
global market
 
host invasion
 
immune evasion mechanisms
 
invasion strategies
 
life cycle
 
myxosporeans
 
recent years
 
sex reversal
 
vaccines
 

Ariadna Sitjà-Bobadilla