Work

Rapid Clearance of Tetracapsuloides bryosalmonae Spores by Freshwater Sponge Ephydatia muelleri : Potential Implications for Controlling Proliferative Kidney Disease in Salmonids

Year: 2025

Type: article

Abstract: Host-parasite interactions are influenced by both abiotic and biotic factors. While abiotic drivers, particularly temperature, have received considerable attention in recent years due to global climate change, the role of biotic factors remains comparatively underexplored. The malacosporean parasite Tetracapsuloides bryosalmonae (Tb), which causes proliferative kidney disease in salmonids, is a well-documented example, where elevated temperature and eutrophication have been shown to intensify disease prevalence and severity. In this study, we investigated whether freshwater sponges, known for their particle-filtering capabilities, can graze on malacosporean spores in the aquatic environment, potentially acting as biotic filters that may influence parasite transmission dynamics. Using an experimental setup, we employed environmental DNA sampling to (1) characterise the short-term release of Tb spores from infected 1+ brown trout (Salmo trutta) and (2) assess the ability of freshwater sponge (Ephydatia muelleri) to remove Tb spores from water and function as a bio-sampler. Our results show that sponges significantly reduced Tb DNA concentrations in water. However, their effectiveness as bio-samplers and concentrators of Tb was limited, likely due to the rapid degradation of ingested Tb DNA. These results suggest that freshwater sponges may function as natural biological controllers of Tb by filter feeding on its infectious planktonic stages in natural environments.

Source: Journal of Fish Diseases

DOI: 10.1111/jfd.70102

Authors: Lauri Saks, Lilian Pukk, Siim Kahar, Magnus Lauringson, Anti Vasemägi

Institutions: Estonian University of Life Sciences, University of Tartu, Swedish University of Agricultural Sciences

Language: English

Topic: Myxozoan Parasites in Aquatic Species

Subfield: Cancer Research

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDGs: Life below water, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $5,450