Remoras Slip Into Manta Ray Cloacal Zones, Study Finds

Marine researchers have documented that remoras can slip into the cloacal cavity of giant manta rays, a behavior dubbed “cloacal diving.” Scientists suggest the tactic may shield the hitchhikers from predators, grant access to leftover meals, or simply serve as a stealthy transport method.

Remoras Exploit Manta Ray Cloacal Space

The observation, published in a leading marine‑biology journal, follows months of underwater video from the Maldives, where divers recorded the fish maneuvering into the ray’s vent while it glided at ↑ 10% typical speed. Researchers cite Reuters for corroborating footage of similar symbiosis in other pelagic species.

“It’s a clever shortcut that could redefine how we view commensal relationships,” said Dr. Lina Ortiz, a marine ecologist.

While the exact advantage remains under study, the behavior may mirror past findings where remoras attach to sharks, gaining scraps and protection. The discovery arrives as marine biologists reassess ecosystem dynamics after the pandemic disrupted global research expeditions.

Intel provided by Sebastian Thorne (European Affairs Analyst).