Pathogenic strategies of fish parasites

Parasitism occurs in almost all lineages of the tree of life, imposing the acquisition of a variety of hosts and microhabitats through organisms' independent evolution and diversification from non-parasitic ancestors. Most of these parasitic lineages are microbial, representing bacteria, fungi, protists, and microbial metazoans. Many of them are of great public health and economic importance and pose a serious threat to the welfare of humans, livestock, and plants. Several examples of extensively studied pathogenic organisms have shown that they are equipped with sophisticated tools to manipulate host cell invasion, which is necessary to initiate the infection. Interestingly, comparative genomics has shown that many pathogenic microbial and non-microbial taxa employ similar strategies (e.g., adapted organelles, specific behaviors, functional gene groups, biochemical pathways, etc.) to evade host immune mechanisms and establish the replication within the host. Nevertheless, our knowledge of the key mechanisms that govern their adaptive strategies and their ability to invade and successfully reproduce in the host is still limited for many parasitic taxonomic groups.



Today, aquaculture is one of the fastest growing food sectors, accounting for a large portion of global food production. The economic losses caused by various parasite groups are immense. The severity of infections in farmed fish and wild fish populations has been also related to increasing water temperature, predicting a massive increase of parasitic load in the future due to the climate change. In order to develop efficient methods to predict and control infections, it is critical to understand the key mechanisms that parasites use to invade, survive, and successful proliferation within their host.



This special issue focuses on parasites that infect fish, shellfish (including mollusks and crustaceans). It aims to bring together a wide range of studies that combine morphological, ecological, and molecular approaches to trace the key strategies and pathogen-associated molecular patterns that the microbial parasites use for invasion and successful reproduction in fish and shellfish. The topic may also include the study of non-microbial metazoan parasites such as helminths. Combining this type of information from different microbial and non-microbial groups will allow us to elucidate homologous genes and strategies activated during pathogenesis and propose control measures against the pathogens.



We invite you to submit research articles, review articles, and short communications for this special issue, which brings together topics on mechanisms of parasites’ pathogenesis that will be of great interest to a broad audience.