Big Red Jelly

Big Red Jelly (Tiburonia granrojo)

A ‘Big Red’ Jellyfish swims past Jason at the Slope Base site ~ 68 miles offshore. Credit: UW/NSF-OOI/WHOI. V20.

Tiburonia granrojo, also known as the Big Red Jelly, is a unique species of jellyfish found in the eastern and northeastern Pacific Ocean. Unlike most jellyfish, it has thick, fleshy arms hanging beneath its main body, instead of tentacles. In addition, it can grow to enormous size, with the largest specimens reported at around 3 meters in diameter. As the name would suggest, T. granrojo is distinct for its deep, opaque red coloration.

Big Red is often seen hovering in the water above and around Axial and Slope Base, usually between 300 and 1000 meters deep in the mesopelagic zone. To date, the largest specimen observed is less than 50 cm in diameter.