High Microeukaryotic Diversity in the Cold-Seep Sediment

Area of Science:

• Marine Biology
• Microbial Ecology
• Deep-Sea Ecosystems

Background:

• Chemosynthetic ecosystems, like cold seeps, host unique microbial communities.
• Understanding microeukaryotic diversity and community structure in these environments is crucial but limited.
• Parasitic microeukaryotes play an underappreciated role in marine ecosystems.

Purpose of the Study:

• To investigate microeukaryotic diversity and community structure in the Haima cold seep.
• To identify factors regulating microeukaryotic communities in different seep habitats.
• To explore the role of parasitic microeukaryotes in cold seep ecosystems.

Main Methods:

• High-throughput sequencing of 18S rRNA genes from sediment cores.
• Comparison of microeukaryotic communities across active, less active, and non-seep regions.
• Analysis of community structure, diversity (α, β, γ), and influencing factors (metazoan richness, dispersal, phylogeny).

Main Results:

• Cold seep regions showed higher abundance and diversity of parasitic microeukaryotes (Apicomplexa, Syndiniales).
• Microeukaryotic community heterogeneity was greater between habitats than within, increasing with phylogenetic depth.
• Microeukaryotic α-diversity was positively correlated with metazoan richness and dispersal rate.
• β-diversity was driven by heterogeneous selection from metazoan communities.
• Cold seeps exhibited significantly higher overall (γ) diversity, indicating they are microeukaryotic hotspots.

Conclusions:

• Cold seep sediments are significant hotspots for marine microeukaryotic diversity.
• Parasitic microeukaryotes are key components of cold seep ecosystems.
• Metazoan communities play a critical role in shaping microeukaryotic diversity and structure through host-parasite interactions.
• Cold seeps contribute significantly to marine biodiversity maintenance and promotion.