Marine Biologists Observed Amphipods Riding Sea Spiders
Researchers documented deep-sea shrimp-like amphipods attached to giant sea spiders in the southeastern Pacific Ocean.
Updated on Sept. 18, 2026 in Environmental
In November 2024, scientists utilizing the robotic submersible SuBastian observed amphipods hitchhiking on giant Colossendeis colossea sea spiders near the Chilean margin. The team recorded the interactions at depths of 10,000 feet.
Why it matters
These observations provide rare insight into symbiotic behaviors within the deep-sea ecosystem, highlighting interactions that remain largely undocumented due to the extreme environments involved.
The researchers employed the robotic submersible SuBastian to reach a depth of 10,000 feet in the Pacific. They documented two distinct occurrences 140 miles apart, with one spider carrying at least three amphipods.
The players
SuBastian
This is a specialized robotic submersible used by researchers to conduct in situ deep-sea exploration at extreme depths.
Ecology
This is a scientific journal that published the research findings regarding the deep-sea symbiotic observations in September 2026.
The details
The research team observed the amphipods physically attached to the bodies of the sea spiders during two separate instances. These findings were further detailed in a study published in the journal Ecology in September 2026.
Timeline
A researcher described M. abyssorum attached to a sea spider in 1927.
The team first observed amphipods riding on a sea spider in November 2024.
A second instance was observed 140 miles away four days after the first sighting in November 2024.
A study reported amphipods on a different sea spider in 2025.
The research paper was published in the journal Ecology in September 2026.
Deeper Dive
This discovery extends the 1927 observation of M. abyssorum attached to a sea spider by documenting multiple recent instances of the behavior.
Understanding these deep-sea relationships may eventually lead to new insights into how specialized marine species adapt to extreme, high-pressure environments. Such knowledge informs broader scientific databases on deep-ocean biodiversity and resilience.
The takeaway
These findings underscore how much of the deep ocean remains a mystery to current science. Continued exploration of extreme habitats is essential for mapping the complex survival strategies utilized by marine life.
What happens next
Scientists plan to conduct further studies using continued in situ observations and genetic analysis to better understand these deep-sea interactions.
Further reading
Learn more about ongoing studies in our Environmental section.
