Discovery of a novel sulfur-oxidizing endosymbiont (Ca. Vesicomyosocius atacamensis) associated with a newly described Archivesica species from the Atacama Trench.

Authors

Daniel Carrizo, Laura Sánchez-García, Javier Sánchez-España, Olga Prieto-Ballesteros, Isabel Herreros, Nikolaos V Schizas, Guillermo Guzman, Alexis Gacitua, Antonio Molina, Mara Laguna-Castro, Miguel Arribas Tiemblo, Karolina Rivera-Osorio, Óscar Ercilla Herrero, Victoria Baca, Amber Y X Wu, Carlos González-Silva, Rodrigo Azua-Bustos, Andrew Palmer, Caitlyn Hubric, Walter Siefeld Kowald, Muriel Rivera, Cristian Vargas, Jacek Wierzchos, Armando Azua-Bustos

Published in

Scientific reports. Jul 14, 2026. Epub Jul 14, 2026.

Abstract

Here we report the microbiome composition and lipid (molecular and isotopic) profile of gills from Archivesica sp. Atacama., a new species of deep-sea bivalve family Vesicomyidae collected at 2839 m depth on the eastern slope of the Atacama Trench. Metabarcoding unveiled that 99.44% of the microbial ASVs (Amplicon Sequence Variant) obtained from this bivalve's gills belonged to Ca. Vesicomyosocius sp. atacamensis, a bacterium closely related to symbionts of other vesicomycoids based on the 16 S rRNA phylogeny (a putative chemoautotrophic sulfide-oxidizing bacterium Form I RubisCO). Additional ASVs included microbes from taxa known for their ability to oxidize sulfur. Consistent with the microbiome composition, the analysis of lipid biomarkers in the gills revealed a high abundance of C_16:1ω7 and C_18:1ω7 fatty acids, well-known markers of sulfide-oxidizing (thiotrophic) bacterial metabolisms. The δ¹³C values of the bivalve's bulk gills (-35.5‰) and of individual fatty acids (-40.0 to -46.5‰) were typical of bivalves hosting thiotrophic endosymbionts utilizing form I RubisCO for carbon fixation. In addition, nearby sediments showed a significant presence of terminal branched (iso/anteiso C₁₃-C₁₇), mid branched (10Me-C₁₆ and 10Me-C₁₈) and cyclopropyl (Cy₁₇ and Cy₁₉) fatty acids, coherent with sulfate-reducing bacterial (SRB) communities found by metabarcoding. These findings confirm that thiotrophic symbiosis provides energy for the new deep-sea Archivesica bivalve reported here.

PMID:
42448797
Bibliographic data and abstract were imported from PubMed on 15 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.