Remora Fish
Scientific name Echeneidae
Remoras — often called “suckerfish” — are fascinating fish best known for hitching rides on larger marine animals. Their most distinctive feature is a flat suction disc on top of their head, evolved from a dorsal fin, which allows them to attach securely to sharks, turtles, rays, whales and even boats.
Around Koh Tao, remoras are sometimes seen attached to turtles, large rays or occasionally reef sharks. They may also swim freely nearby before reattaching to a host.
This relationship is generally considered commensal — the remora benefits by gaining transport, protection and access to food scraps, while the host is largely unaffected. In some cases, remoras may even help remove parasites from their host’s skin.
They have elongated bodies, dark grey to brown colouring and strong swimming ability when detached.
Find Remora Fish at...
Divemaster's tip
If you spot a turtle or shark, check carefully — you may see one or more remoras attached underneath or along the body.
Avoid attempting to touch or disturb them; remoras may detach and reattach quickly if stressed.
What do they eat?
Remoras feed on parasites, dead skin, and leftover food scraps from their host’s meals.
When swimming independently, they may also consume small fish and plankton.
By cleaning parasites and recycling scraps, they play a subtle but useful role in the marine ecosystem around Koh Tao.
