animal Type
Maximum Size

45 cm

(18 inches)


1,600–2,400 m

(5,200–7,900 feet)



in the midnight (bathypelagic) zone


Small fishes


Northeastern Pacific Ocean

Central California to Baja California


This jelly-like animal fishes for its meals.

Siphonophores are close cousins of jellies. They’re fragile creatures composed of individual, specialized parts connected to each other in a chain. Some parts pulse and steer the colony, others stun and ingest prey. Siphonophores thrive in the midwater where there aren’t any sharp surfaces to damage their delicate bodies. MBARI’s remotely operated vehicles, or ROVs, have revealed a surprising diversity of siphonophores in Monterey Bay and we’ve learned they’re important predators in the ocean’s depths.

We’ve discovered several remarkable new siphonophore species, including this especially cunning predator—the angler siphonophore (Erenna sirena). In a dazzling display of predatory prowess, it dangles luminescent lures that mimic crimson crustaceans and attract unsuspecting fishes. Zap! When a curious lanternfish gets too close, the siphonophore’s tentacles deliver a powerful sting and snare a meal.



Burns, J.A., K. P. Becker, D. Casagrande, J. DanielsP. RobertsE. Orenstein, D. M. Vogt, Z. E. Teoh, R. Wood, A.H. Yin, B. Genot, D.F. Gruber, K. Katija, R.J. Wood, B.T. Phillips. 2024. An in situ digital synthesis strategy for the discovery and description of ocean life. Science Advances, 10(eadj4960).

Pugh, P.R., and S.H.D. Haddock. 2016. A description of two new species of the genus Erenna (Siphonophora, Physonectae, Erennidae), with notes on recently collected specimens of other Erenna species. Zootaxa, 4189: 401–446.