Uploaded May 2026 | Updated September 2026, 3 weeks ago
When remora fish get scared, they sometimes take shelter… inside a manta ray’s backside. Researchers call this newly observed behavior “cloacal diving.” Remoras, also known as suckerfish, are known for latching onto larger animals and have been seen diving into whale-shark cloacae before, but this is the first time researchers have seen the behavior with manta rays. A study published today documents cloacal diving across all known manta ray species and in three separate ocean basins between 2010 and 2025.
Typically the remora-manta ray relationship is considered either commensal (where the remoras benefit and the manta rays are neither helped nor harmed) or mutualistic (both species benefit). But cloacal diving could tip the scales towards a more parasitic relationship. While it is unclear how often and for how long cloacal diving happens, it could have negative effects and, at the very least, the manta rays don't seem to like it.
Credit: Jessica Pate/Marine Megafauna Foundation
#ocean #cloacas #biology #science #fish
When remora fish get scared, they sometimes take shelter… inside a manta ray’s backside. Researchers call this newly observed behavior “cloacal diving.” Remoras, also known as suckerfish, are known for latching onto larger animals and have been seen diving into whale-shark cloacae before, but this is the first time researchers have seen the behavior with manta rays. A study published today documents cloacal diving across all known manta ray species and in three separate ocean basins between 2010 and 2025.
Typically the remora-manta ray relationship is considered either commensal (where the remoras benefit and the manta rays are neither helped nor harmed) or mutualistic (both species benefit). But cloacal diving could tip the scales towards a more parasitic relationship. While it is unclear how often and for how long cloacal diving happens, it could have negative effects and, at the very least, the manta rays don't seem to like it.
Credit: Jessica Pate/Marine Megafauna Foundation
#ocean #cloacas #biology #science #fish
