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Methane seeps harbor uncharacterized animal–microbe symbioses with unique nutritional strategies. Three undescribed sea spider species (family Ammotheidae; genus Sericosura) endemic to methane seeps were found along the eastern Pacific margin, from California to Alaska, hosting diverse methane-and methanol-oxidizing bacteria on their exoskeleton. δ13C tissue isotope values of in situ specimens corroborated methane assimilation (−45‰, on average). Live animal incubations with 13C-labeled methane and methanol, followed by nanoscale secondary ion mass spectrometry, confirmed that carbon derived from both compounds was actively incorporated into the tissues within five days. Methano-and methylotrophs of the bacterial families Methylomonadaceae, Methylophagaceae and Methylophilaceae were abundant, based on environmental metagenomics and 16S rRNA sequencing, and fluorescence and electron microscopy confirmed dense epibiont aggregations on the sea spider exoskeleton. Egg sacs carried by the males hosted identical microbes suggesting vertical transmission. We propose that these sea spiders farm and feed on methanotrophic and methylotrophic bacteria, expanding the realm of animals known to harness C1 compounds as a carbon source. These findings advance our understanding of the biology of an understudied animal lineage, unlocking some of the unique nutritional links between the microbial and faunal food webs in the oceans.
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This content will become publicly available on July 1, 2026
Methane-powered sea spiders: Diverse, epibiotic methanotrophs serve as a source of nutrition for deep-sea methane seep Sericosura
Methane seeps harbor uncharacterized animal–microbe symbioses with unique nutritional strategies. Three undescribed sea spider species (family Ammotheidae; genusSericosura) endemic to methane seeps were found along the eastern Pacific margin, from California to Alaska, hosting diverse methane- and methanol-oxidizing bacteria on their exoskeleton. δ13C tissue isotope values of in situ specimens corroborated methane assimilation (−45‰, on average). Live animal incubations with13C-labeled methane and methanol, followed by nanoscale secondary ion mass spectrometry, confirmed that carbon derived from both compounds was actively incorporated into the tissues within five days. Methano- and methylotrophs of the bacterial families Methylomonadaceae, Methylophagaceae and Methylophilaceae were abundant, based on environmental metagenomics and 16S rRNA sequencing, and fluorescence and electron microscopy confirmed dense epibiont aggregations on the sea spider exoskeleton. Egg sacs carried by the males hosted identical microbes suggesting vertical transmission. We propose that these sea spiders farm and feed on methanotrophic and methylotrophic bacteria, expanding the realm of animals known to harness C1 compounds as a carbon source. These findings advance our understanding of the biology of an understudied animal lineage, unlocking some of the unique nutritional links between the microbial and faunal food webs in the oceans.
more »
« less
- Award ID(s):
- 2048720
- PAR ID:
- 10610773
- Publisher / Repository:
- US National Academy of Sciences
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 122
- Issue:
- 26
- ISSN:
- 0027-8424
- Subject(s) / Keyword(s):
- methane seep symbiosis Pycnogonida methane oxidation
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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