Offshore and away from the shallow, coastal waters is the open sea, a vast, fluid and edgeless world. Life in the open sea is divided into two broad groups: drifters (plankton) and swimmers. Plankton, like this big red jelly, generally drift or weakly swim with the currents. Although relatively common, scientists know very little about the natural history of Tiburonia granrojo, or “Big Red.” This jelly lives 650 to 1,500 meters below the ocean surface, and has a bell diameter up to one meter.