Trematode community structure in the pulmonate snail Physa gyrina

Area of Science:

• Ecology
• Parasitology
• Malacology

Background:

• Trematode communities in freshwater snails are crucial for understanding host-parasite dynamics.
• Physa gyrina snails are common hosts for various trematode species.
• Previous studies suggest lower species richness in snail trematode infracommunities.

Purpose of the Study:

• To investigate the trematode community structure in Physa gyrina snails.
• To determine the prevalence and co-occurrence patterns of trematode species.
• To explore factors influencing trematode infracommunity richness and composition.

Main Methods:

• Collected 1,181 Physa gyrina snails from Charlie's Pond, North Carolina over 12 months.
• Identified and quantified 6 trematode species infecting the snails.
• Analyzed infection data to assess species richness, prevalence, and co-infection patterns.

Main Results:

• Observed a high species richness in snail infracommunities, with 18.4% of infected snails harboring multiple trematode species.
• Halipegus eccentricus was the most prevalent parasite, found in nearly 50% of snails during peak season and in 88.4% of multiple infections.
• No negative interspecific interactions or dominance hierarchies were detected among trematodes.
• Parasite-induced host mortality by H. eccentricus was observed to increase species diversity in larger snails.

Conclusions:

• High snail vagility and environmental temporal heterogeneity contribute to frequent multi-species trematode infections.
• Halipegus eccentricus plays a significant role in shaping trematode community structure and host population dynamics.
• Continuous snail recruitment and fluctuating parasite infective stages influence the overall component community composition.