Uploaded August 2026 | Updated September 2026, 2 weeks ago
This jelly launched decades of discovery at MBARI. Researchers first encountered the bumpy jelly (Stellamedusa ventana) in 1990 while exploring Monterey Bay with the remotely operated vehicle Ventana.
The lack of tentacles immediately caught our attention. Most jellies trail long, fine tentacles to stun prey, but the bumpy jelly is covered in tiny bumps loaded with stinging cells. Stellamedusa can capture prey across their entire surface. As they swim, those stinging cells immobilize plankton in their path. Four lacy mouth-arms then sweep the bell's edge to collect the catch—a hunting strategy known in only a small number of deep-sea jellies.
MBARI's growing fleet of autonomous robots, equipped with advanced imaging systems, gives us a persistent presence in the twilight waters Stellamedusa calls home. Long-term studies have revealed that the bumpy jelly is far more common than we first thought, sometimes appearing in blooms deep underwater. Instead of sporadic snapshots, we now have a fuller picture of life in the twilight zone, a reminder of how much more there is to learn as ocean exploration technology advances.
Stellamedusa is just one of many wonders we've uncovered in the deep. MBARI's research and technology continue to reveal the stunning diversity of life in Earth's largest habitat. We’ve discovered more than 300 new species in Monterey Bay and beyond—each one helps us better understand and protect our blue planet.
Learn more about this and other fascinating animals of the deep: mbari.org/animal/bumpy-jelly
Research publication:
Raskoff, K.A. and G.I. Matsumoto. 2004. Stellamedusa ventana, a new mesopelagic scyphomedusa from the eastern Pacific representing a new subfamily, the Stellamedusinae. Journal of the Marine Biological Association of the United Kingdom, 84(1): 37-42. doi.org/10.1017/S0025315404008884h
Script writer: Raúl Nava
Science advisor, narrator: George Matsumoto
Editor: Kyra Schlining
Motion graphics: Madeline Go
Production team: Rose Dalrymple, Larissa Lemon, George Matsumoto, Raúl Nava, Kyra Schlining, Nancy Jacobsen Stout, Susan von Thun
Music: Pond5 074612363 by Mv_production
This jelly launched decades of discovery at MBARI. Researchers first encountered the bumpy jelly (Stellamedusa ventana) in 1990 while exploring Monterey Bay with the remotely operated vehicle Ventana.
The lack of tentacles immediately caught our attention. Most jellies trail long, fine tentacles to stun prey, but the bumpy jelly is covered in tiny bumps loaded with stinging cells. Stellamedusa can capture prey across their entire surface. As they swim, those stinging cells immobilize plankton in their path. Four lacy mouth-arms then sweep the bell's edge to collect the catch—a hunting strategy known in only a small number of deep-sea jellies.
MBARI's growing fleet of autonomous robots, equipped with advanced imaging systems, gives us a persistent presence in the twilight waters Stellamedusa calls home. Long-term studies have revealed that the bumpy jelly is far more common than we first thought, sometimes appearing in blooms deep underwater. Instead of sporadic snapshots, we now have a fuller picture of life in the twilight zone, a reminder of how much more there is to learn as ocean exploration technology advances.
Stellamedusa is just one of many wonders we've uncovered in the deep. MBARI's research and technology continue to reveal the stunning diversity of life in Earth's largest habitat. We’ve discovered more than 300 new species in Monterey Bay and beyond—each one helps us better understand and protect our blue planet.
Learn more about this and other fascinating animals of the deep: mbari.org/animal/bumpy-jelly
Research publication:
Raskoff, K.A. and G.I. Matsumoto. 2004. Stellamedusa ventana, a new mesopelagic scyphomedusa from the eastern Pacific representing a new subfamily, the Stellamedusinae. Journal of the Marine Biological Association of the United Kingdom, 84(1): 37-42. doi.org/10.1017/S0025315404008884h
Script writer: Raúl Nava
Science advisor, narrator: George Matsumoto
Editor: Kyra Schlining
Motion graphics: Madeline Go
Production team: Rose Dalrymple, Larissa Lemon, George Matsumoto, Raúl Nava, Kyra Schlining, Nancy Jacobsen Stout, Susan von Thun
Music: Pond5 074612363 by Mv_production
