Scientists have discovered three new species of sea spiders off the U.S. West Coast that survive by feeding on methane-fueled bacteria. These Sericosura sea spiders may even pass these bacteria to their hatchlings as an initial food source. In the deep sea, certain species exist in symbiosis with bacteria that convert methane and oxygen into sugars and fats the spiders can consume.
“Just like you would eat eggs for breakfast, the sea spider grazes the surface of its body, munching on the bacteria for nutrition,” said Shana Goffredi, a professor of biology at Occidental College in Los Angeles and the study’s principal investigator. This unique nutrition strategy has never been observed in sea spiders before. Unlike other sea spiders that use large fangs to capture prey, these Sericosura species lack the necessary appendages for such hunting.
Lab observations revealed they are more like farmers harvesting methane-fueled bacteria from their own bodies. This novel form of sustenance enables them to survive in the deep-sea environment. Nicole Dubilier, a marine biologist not involved in the study, explained that in the dark depths of the ocean, microbes evolved to use chemicals instead of sunlight for energy.
Methane-fed nourishment in sea spiders
When marine life dies and decomposes on the seafloor, methane is released and microbes feeding on this methane attach themselves to sea animals to remain near the source. By analyzing the isotopes in the spiders’ tissues, scientists found the bacteria were not just hitching a ride but were also being consumed by the spiders.
This interaction allows a small portion of the bacterial population to propagate, despite predation by the spiders. The newly discovered Sericosura spiders are small, translucent, and span about 0.4 inches in length. Collected from different areas off the coast of Southern California and Alaska, the highly localized populations indicate further exploration might uncover more similar species.
The spiders have a unique reproductive method where female spiders shoot hundreds of eggs from their kneecaps, and the males collect these eggs into saclike bundles. Once hatched, the bacteria on the father spiders attach to the hatchlings, providing them an early food source. Further exploration could reveal additional species and provide deeper insights into the diverse and interconnected deep-sea ecosystem.
Understanding these interactions is crucial for sustainably utilizing the ocean’s resources and protecting unique marine habitats. Shana Goffredi emphasized the importance of this research, saying, “We can’t ever hope to sustainably use the oceans if we don’t really understand the oceans.”
Kirstie a technology news reporter at DevX. She reports on emerging technologies and startups waiting to skyrocket.
