Sea Spiders Feed on Methane

Deep in methane rich seeps off Southern California, sea spiders survive by grazing methane fed bacteria on their legs.

Sea Spiders Thrive on Methane in Deep Ocean

Researchers publishing in the Proceedings of the National Academy of Sciences describe Sericosura sea spiders living more than 3,350 feet below the surface in methane seeps off Southern California. Using remotely operated vehicles, the team collected specimens and found thousands of methanotroph bacteria coating the spiders’ legs, creating a living food farm. The spiders reportedly graze this bacterial layer to obtain calories in a lightless, nutrient-poor environment.

The study outlines a symbiosis where bacteria convert methane into sugars the spiders can absorb. It also notes a surprising behavior: male spiders carry egg sacs on their knees and transfer the same bacteria to their offspring, a form of parental microbiome inheritance.

Experts say the finding shifts how scientists view deep sea food webs, placing microbes and host animals in a tightly coupled cycle. The researchers discuss potential implications for methane cycling in the ocean, suggesting these animals may help trap methane at the seafloor, though the climate impact remains to be measured.

Editorial take This find challenges the idea that deep sea life is mostly microbes and passive scavengers. It shows a complex life form using bacteria as a constant food source, a model of resilience in extreme conditions. Yet the climate angle is still uncertain; researchers should avoid inflating the impact on global methane budgets until broader data are in.

Framing the finding as a sign of a broader microbial partnership in the abyss invites more research into how widespread such strategies are. Funding and policy discussions may hinge on how science translates small observations into broader climate claims.

Highlights

The deep ocean keeps surprising us with life that rewrites the rules of survival.