Story perspectives

Study Documents Unwelcome Remora Cloacal Diving in Manta Rays

5/12/2026

Summary

Story summary

U.S. researchers led by University of Miami’s Catherine Macdonald published a study documenting remora fish entering manta rays’ cloacae and naming the behavior “cloacal diving.”
The paper records seven events from 2010 to 2025 across three manta-ray species.
Observations were gathered by Marine Megafauna Foundation in three basins.
Researchers say manta rays do not welcome intrusion, noting remoras entered so far their tail tip showed while others remained outside on rays.

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Story summary

U.S. researchers led by University of Miami’s Catherine Macdonald published a study documenting remora fish entering manta rays’ cloacae and naming the behavior “cloacal diving.”
The paper records seven events from 2010 to 2025 across three manta-ray species.
Observations were gathered by Marine Megafauna Foundation in three basins.
Researchers say manta rays do not welcome intrusion, noting remoras entered so far their tail tip showed while others remained outside on rays.