Sea Spiders Host Methane-Eating Bacteria on Their Bodies

Quick Summary

• discovery and Research: Scientists at Occidental College studied sea spiders near methane seeps in teh Pacific Ocean, uncovering three new species from the genus Sericosura that live exclusively near these seeps.Unlike other sea spiders that eat invertebrates, these species mostly obtain nutrition by consuming bacteria cultivated on their exoskeletons.
• Bacteria’s Role: The bacteria thrive by metabolizing methane and methanol emitted from the seafloor. Researchers observed them forming “volcano-like” clusters on spider exoskeletons, which were eaten by the spiders using hard lips and three small teeth.
• Confirmation of Farming Behaviour: Using radioactive labeling techniques, researchers tracked carbon molecules from methane into spider tissues via bacterial consumption, affirming this symbiotic farming relationship.
• Mutual Benefits: The bacteria benefit from mobility provided by sea spiders to stay near viable methane sources while the spiders harvest energy-rich food inaccessible otherwise.
• Importance of Study: Similar symbiotic relationships are increasingly discovered around methane seep ecosystems (e.g., tube worms). These systems sustain life independent of solar energy.

Image:
!Sea spider from the genus Sericosura

Credit: Biance Dal Bó