Remoras Are Diving Into Manta Ray “Buttholes.” Really.

Researchers observed seven remora–manta ray interactions that went beyond harmless hitchhiking.

In some cases, remoras entered cloacas or attached under gill slits, leaving injuries consistent with intrusion.

The study covered reef, giant oceanic, and Atlantic manta rays and was led by the University of Miami’s Shark Research and Conservation Program.

The findings suggest the remora-host relationship may be commensal in some cases, but sometimes parasitic or harmful.

That matters because manta rays are already vulnerable, and invasive remora behavior could add stress, injury, and energy costs.