A Study of Sponge Symbionts from Different Light Habitats

Area of Science:

• Marine microbiology
• Symbiotic microbial ecology
• Bioinformatics

Background:

• Light is a critical environmental factor influencing microbial growth and community development.
• Sponge-associated microbial communities are diverse and play vital ecological roles.
• Understanding factors structuring these communities is essential for marine ecosystem research.

Purpose of the Study:

• To investigate how light availability (dimly lit vs. illuminated habitats) affects prokaryotic communities associated with Cinachyrella kuekenthali and Xestospongia muta.
• To compare prokaryotic communities across different biotopes: sponge hosts, sediment, and seawater.
• To identify specific microbial taxa associated with different light habitats using machine learning.

Main Methods:

• Sampling of sponge species Cinachyrella kuekenthali and Xestospongia muta from illuminated and dimly lit marine environments.
• Collection of associated water and sediment samples for comparative analysis.
• Application of machine learning techniques to analyze prokaryotic community composition (classes, orders, operational taxonomic units - OTUs) and identify habitat-specific features.

Main Results:

• Biotope (sponge species, sediment, seawater) was the primary determinant of prokaryotic community variation.
• Light habitat significantly influenced prokaryotic community composition in both C. kuekenthali and X. muta.
• Machine learning identified distinct microbial taxa associated with illuminated (e.g., Alphaproteobacteria, Rhodospirillales) and dimly lit (e.g., Dehalococcoidia, Spirochaetia) habitats.

Conclusions:

• Both the host sponge species and the light environment are crucial factors structuring associated prokaryotic communities.
• Specific bacterial classes and orders are indicative of either shallow, illuminated waters or deeper, dimly lit marine zones.
• Despite light's influence, significant intra-habitat variation underscores the complex interplay of factors shaping sponge microbiomes.