This jelly launched decades of discovery at MBARI. 

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 unsuspecting prey. How does Stellamedusa capture food without tentacles? Look closely, and you’ll see this jelly is covered in tiny bumps loaded with stinging cells. Stellamedusa can capture prey across their entire surface. 

As Stellamedusa swims, tiny stinging cells immobilize plankton in their path, then those four lacy mouth-arms sweep the edge of the jelly’s bulbous bell to collect a meal. Just a handful of deep-sea jellies are known to use this strategy.

Three months after our first encounter, we spotted a second bumpy jelly—and then didn’t see another for nine years. It took more than a decade to log enough sightings to be able to describe this species.

But naming a new animal is just the first step. We still have a lot of unanswered questions about how Stellamedusa eats, reproduces, and lives.

MBARI’s growing fleet of nimble autonomous robots is providing new insights into the twilight waters that Stellamedusa calls home. Equipped with innovative imaging systems, these robots give us a persistent presence in the ocean, showing us that the bumpy jelly is more common than we first thought, sometimes occurring in blooms deep underwater.

Instead of sporadic snapshots, we now have a more complete picture of life in the ocean’s twilight zone, a reminder of how much more we can learn as ocean exploration technology advances.

Stellamedusa is just one of many wonders we’ve uncovered in the deep. MBARI research and technology are helping reveal the stunning diversity of life in the largest habitat on Earth. We’ve discovered more than 300 new species in the depths of Monterey Bay and beyond. Each discovery helps us better understand and protect our blue planet.