Life at the extremes: Riding a ghost

by Pablo Taranto, University of Buenos Aires
October 21, 2026

One of the most extraordinary scenes captured by “Life at the Extremes,” the oceanographic campaign led by the Faculty of Exact Sciences at the University of Buenos Aires that explored previously unseen deep-sea ecosystems in the Argentine Sea, was the dance of a giant ghost jellyfish accompanied by small blue fish. This specimen of Stygiomedusa gigantea, associated with a school of juvenile Centrolophus niger , was not only “observed” by researchers in an underwater canyon off the coast of Patagonia. The interaction between the two species was also broadcast live on YouTube .

Indeed, the expedition carried out between December 2025 and January 2026 aboard the Schmidt Ocean Institute ‘s research vessel Falkor (Too) allowed for live streaming of deep-sea fauna along the Argentine continental margin, obtaining extremely high-definition images captured by the cameras of the remotely operated vehicle (ROV) SuBastian . (See video at the end of the article).

And one of the most remarkable findings of that campaign – published in Ecology , the journal of the Ecological Society of America , under the title Riding a phantom – is the one that tries to unravel what the association between this giant jellyfish and the small “romerillos” or “rudderfish” – two of the names given to C. niger – consists of in the mesopelagic zone, at a depth of between 250 and 257 meters.

Keep reading (in Spanish): https://nexciencia.exactas.uba.ar/captan-interaccion-medusa-fantasma-gigante-peces-romerillos-falkor-too-smith-ocean-institute-mar-argentino-profundo-maria-emilia-bravo

Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.70542