Bacterial communities associated with the wood-feeding gastropod Pectinodonta sp. (Patellogastropoda, Mollusca)

Abstract

Even though their occurrence was reported a long time ago, sunken wood ecosystems at the deep-sea floor have only recently received specific attention. Accumulations of wood fragments in the deep sea create niches for a diverse fauna, but the significance of the wood itself as a food source remains to be evaluated. Pectinodonta sp. is a patellogastropod that exclusively occurs on woody substrates, where individuals excavate deep depressions, and is thus a potential candidate for a wood-eating lifestyle. Several approaches were used on Pectinodonta sampled close to Tongoa island (Vanuatu) to investigate its dietary habits. Host carbon is most likely derived from the wood material based on stable isotopes analyses, and high cellulase activity was measured in the digestive mass. Electron microscopy and FISH revealed the occurrence of two distinct and dense bacterial communities, in the digestive gland and on the gill. Gland-associated 16S rRNA gene bacterial phylotypes, confirmed by in situ hybridization, included members of three divisions (Alpha- and Gammaproteobacteria, Bacteroidetes), and were moderately related (90-96% sequence identity) to polymer-degrading and denitrifying bacteria. Gill-associated phylotypes included representatives of the Delta- and Epsilonproteobacteria. The possible involvement of these two bacterial communities in wood utilization by Pectinodonta sp. is discussed.

Microbial Communities in Sunken Wood Are Structured by Wood-Boring Bivalves and Location in a Submarine Canyon

“…In wood from the open slope, the most abundant OTU (OTU 5) belonged to the Rhodobacteriales order of Alphaproteobacteria and was 100% similar to a sequence found earlier in oak wood from Blanes Canyon (Blanes 1043, [17]) and distantly related (91%) to bacteria found in guts of the marine wood-feeding gastropod Pectinodonta sp. (Patellogastropoda, Mollusca) [50] and the chiton Nierstraszella lineata [42]. Another abundant OTU (OTU 7) was identified as a Gammaproteobacterium related to clones from gorgon or seafloor lava (96%).…”

Decapod crustaceans from the Paleocene (Danian) of the Paris Basin (Vigny stratotype and allied localities) and a limpet palaeoassociation

“…As the rest of the carapace is missing, any potential fixation scar on the carapace remains outside of the limpet and cannot be observed. Today and in the fossil record limpets are known to live on many substrates including floating wood (Storry et al 2006;Kiel et al 2009;Zbinden et al 2010) and ammonites (Kase et al 1994(Kase et al , 1998Taylor & Wilson 2003). However, adult gastropods as epibionts of extant brachyurans have not been previously reported, although they are found on limulids (Botton & Ropes 1988;Penn & Brockman 1995).…”

Beta-diversity on deep-sea wood falls reflects gradients in energy availability

“…Energy is transferred from wood to associated animals via both heterotrophic and chemotrophic pathways. Heterotrophic, cellulose-degrading microflora such as bacteria and fungi are also fed upon by other organisms [6,7]. Some animals may also digest and assimilate carbon from wood directly [6,8].…”