Molecular evidence of host-parasite interactions between zooplankton and Syndiniales

S Zamora-Terol,A Novotny,M Winder

doi:10.1007/s10452-020-09816-3

S Zamora-Terol, A Novotny + Show 1 more

Open Access

https://doi.org/10.1007/s10452-020-09816-3

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Abstract

Although parasitism is one of the most prevalent interactions in nature, studies of aquatic food webs rarely include parasites. Syndiniales (Dinophyceae, Alveolata) is a diverse parasitic group of dinoflagellates, common in all marine environments, and are described as dominant components of pelagic ecosystems. However, their temporal dynamics, prevalence, and host-specificity are poorly known. Using DNA metabarcoding to explore trophic interactions of zooplankton, we found a high proportion of Syndiniales sequence reads associated with the targeted consumers. We observed the occurrence of Syndiniales in copepods, cladocerans, appendicularians, and polychaete larvae, ranging between 11 and 36% relative read abundance, encompassing 11 main putative clades. Zooplankton–Syndiniales interactions showed variability in occurrence across the taxa, but also certain host-specificity. The study suggests that the observed copepod–Syndiniales interactions can be both direct parasitic infections and the result of trophic transmission through potentially infected prey by Syndiniales. Given the quantitative importance of Syndiniales and zooplankton in marine environments, our findings emphasize that their interactions should be recognized as key players in the structure and connectivity of plankton food webs.

Highlights

Parasitism is one of the most prevalent interactions in nature, studies of aquatic food webs rarely include parasites
To highlight the potential relevance of parasites in plankton food webs, here we present a molecular exploration of interactions between Syndiniales and several zooplankton species based on 18S rRNA gene sequencing
We observed a high occurrence of Syndiniales reads associated with diverse zooplankton species during a survey on plankton trophic interactions in the Baltic Sea using 18S rRNA gene sequencing (Fig. 1a)

Summary

Introduction

Parasitism is one of the most prevalent interactions in nature, studies of aquatic food webs rarely include parasites. Syndiniales (Dinophyceae, Alveolata) is a diverse parasitic group of dinoflagellates, common in all marine environments, and are described as dominant components of pelagic ecosystems. Their temporal dynamics, prevalence, and host-specificity are poorly known. Most studies describe the diversity, occurrence, and morphology of zooplankton parasites (Skovgaard 2014; Cachon 1964; Bielecka and Boehnke 2014; Shields 1994), while few have addressed their ecological importance, including their role in population dynamics, leading to an underestimation of their relevance in the marine plankton ecosystem (Agha et al 2016; Clarke et al 2019; Skovgaard and Saiz 2006).

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