Microbiota of the Digestive Glands and Extrapallial Fluids of Clams Evolve Differently Over Time Depending on the Intertidal Position.

Clément Offret,Olivier Gauthier,Christine Paillard,Gwenaelle Le Blay,Charlotte Corporeau,Fabrice Pernet,Philippe Miner,Adeline Bidault,Caroline Fabioux,Garance Despréaux,Bruno Petton

doi:10.1007/s00248-022-01959-0

Abstract

The Manila clam (Ruditapes philippinarum) is the second most exploited bivalve in the world but remains threatened by diseases and global changes. Their associated microbiota play a key role in their fitness and acclimation capacities. This study aimed at better understanding the behavior of clam digestive glands and extrapallial fluids microbiota at small, but contrasting spatial and temporal scales. Results showed that environmental variations impacted clam microbiota differently according to the considered tissue. Each clam tissue presented its own microbiota and showed different dynamics according to the intertidal position and sampling period. Extrapallial fluids microbiota was modified more rapidly than digestive glands microbiota, for clams placed on the upper and lower intertidal position, respectively. Clam tissues could be considered as different microhabitats for bacteria as they presented different responses to small-scale temporal and spatial variabilities in natural conditions. These differences underlined a more stringent environmental filter capacity of the digestive glands.

Highlights

Host-associated microbiota are organized into trophic groups of microorganisms that interact with each other and the organ they colonize
We investigated the diversity and the temporal dynamic of the digestive glands (DG) and extrapallial fluids (EF) microbiota from Manilla clams placed on two intertidal levels in the foreshore during spring revival
Results brought more information regarding specificity of clam tissue microbiota, while both small spatial and temporal scales significantly contributed to the shaping of the DG and EF microbiota

Summary

Introduction

Host-associated microbiota are organized into trophic groups of microorganisms that interact with each other and the organ they colonize. The colonized tissues offer particular physicochemical conditions, and act as micro-habitats Both the host and its associated microbiota contribute to the metabolic specificity of these organs. Associated microorganisms contribute to varying degrees to many metabolic processes and gene expressions that can have major impacts on host nutrition, detoxification, growth, immune system development and resistance to infections [2–4]. They probably play a key role in hosts acclimation to different ecological conditions in fluctuating environments as coastal zones

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