Why Are Fish Hiding in Their Habitats?

Remoras are small fish known for their ability to attach themselves to larger animals. They have a suction cup on their heads that allows them to cling to creatures like sharks, rays, and turtles. Traditionally, it was believed that this relationship benefited both parties. Remoras eat parasites and dead skin from their hosts, while gaining protection and transport. However, new research suggests this connection may not be as helpful as once thought.

Emily Yeager, a PhD student at the University of Miami, highlights a series of troubling findings about remoras. A 2025 study showed that sea turtles with remoras grazed less, and the scientists saw only one example of a remora cleaning a turtle’s shell. In fact, some remoras were observed entering their host’s bodies, including whale sharks.

Yeager’s latest paper argues that remoras might act more like pests. This study revealed that remoras have been found inside the cloacas of manta rays. The term “cloacal diving” was used to describe this unusual behaviour. Yeager and her team collected footage showing remoras inserting themselves into manta rays, causing concern about possible harm.

Researchers continue to explore these interactions. They suspect that a remora inside a manta ray’s cloaca could cause damage or interfere with important functions like breathing and reproduction. Yeager believes this research offers new insights into the complex relationships between remoras and their hosts.

How much do you know?

What do remoras primarily attach themselves to?

Other fish

Larger animals

Coral reefs

Submarine structures

What do remoras use to cling to their hosts?

Claws

Teeth

Suction cup

Gills

What was one benefit traditionally attributed to the relationship between remoras and their hosts?

Remoras eat host's flesh

Hosts provide remoras with shelter

Remoras clean parasites off hosts

Hosts transport remoras to different locations

Who conducted the study mentioned concerning the relationship between remoras and their hosts?

Dr. Richard Dawkins

Emily Yeager

Dr. Jane Goodall

Prof. Charles Darwin

In what year did the study about sea turtles and remoras take place?

2020

2021

2022

2025

What unusual behavior was observed in remoras in relation to manta rays?

Eating their scales

Climbing onto their backs

Inserting themselves into their cloacas

Cleaning their eyes

Remoras are known to detach easily from larger animals.

True False

Traditionally, the relationship between remoras and their hosts was seen as purely beneficial.

True False

Emily Yeager is a PhD student at Harvard University.

True False

Some remoras were found inside the bodies of whale sharks.

True False

Cloacal diving refers to normal behavior for remoras.

True False

Researchers believe remoras may cause damage to their hosts in some cases.

True False

Remoras are small fish known for their ability to attach themselves to .

The suction cup on a remora's head allows it to cling to .

Emily Yeager is a student at the University of Miami.

A 2025 study showed that sea turtles with remoras grazed .

Remoras were observed inserting themselves into the of manta rays.

Yeager believes this research offers new insights into the complex relationships between remoras and their .

This question is required