Host-Parasite Interactions in Aquatic Ecosystems

Host–parasite interactions underpin the structure and function of aquatic ecosystems by shaping population dynamics, community composition and energy flow. Parasites range from single‐celled protists to complex helminths, each exploiting specific host species at various life‐cycle stages. Hosts deploy innate and adaptive immune defences, behavioural avoidance and life‐history adjustments to counter infection, while parasites evolve evasion strategies, immunomodulation and transmission specialisations. These reciprocal adaptations constitute coevolutionary arms races that influence host resistance, parasite virulence and broader ecosystem resilience. Environmental drivers such as temperature, salinity and anthropogenic pollutants modulate infection prevalence and intensity, altering disease outcomes and species interactions at local and global scales. In turn, parasite‐mediated mortality and sublethal effects can regulate host population abundance, facilitate adaptive radiation in hosts and serve as indicators of ecosystem health. Recent advances in molecular tools—from transcriptomics to metaviromics—have illuminated the mechanistic underpinnings of infection processes, enabling integration of ecological, evolutionary and immunological perspectives. Such integrative research informs sustainable fisheries management, conservation of endangered species and mitigation of emerging diseases in the face of climate change.

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Host-Parasite Interactions in Aquatic Ecosystems publication trend

The graph below shows the total number of articles in host-parasite interactions in aquatic ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Cestode: A class of tapeworms that inhabit the intestines of vertebrate hosts and require multiple hosts to complete their life cycle.

Immunopathology: Damage to host tissues resulting from an overactive or misdirected immune response during infection.

Metaviromics: The high‐throughput analysis of viral genetic material within a sample to characterise viral diversity and ecology.

Vertical transmission: The passage of a pathogen or symbiont directly from parent organism to offspring, often through reproductive tissues or early developmental stages.

Coevolutionary arms race: Reciprocal evolutionary changes in interacting species, such as hosts and parasites, driven by mutual selective pressures.

References

1. Population-level immunologic variation in wild threespine stickleback (Gasterosteus aculeatus). Fish & Shellfish Immunology (2024).
2. Characterization of viruses in a tapeworm: phylogenetic position, vertical transmission, and transmission to the parasitized host. The ISME Journal: Multidisciplinary Journal of Microbial Ecology (2020).
3. The three-spined stickleback-Schistocephalus solidus system: an experimental model for investigating host-parasite interactions in fish. Parasitology (2009).
4. The Role of Parasitism in Adaptive Radiations—When Might Parasites Promote and When Might They Constrain Ecological Speciation?. International Journal of Ecology (2012).