This Broom filefish (Amanses scopas) has a unique way of getting a good night's sleep.
A team of marine biologists studying coral reefs at night were diving off Eilat in the Gulf of Aqaba when they spotted the torpid tetradontid anchoring itself to the tip of an Acropora coral using its impressive teeth.
Gal Eyal, Lee Eyal-Shaham and Yossi Loya of Tel-Aviv University found the fish sleeping attached to the same coral tip on three successive nights until a severe storm destroyed its preferred spot.
To the team's surprise the fish was then discovered sleeping in the same fashion on a new coralline cradle a few metres from its previous perch.
This is the first time this 'anchoring' behaviour has been recorded in any fish species.
The team believe the fish has developed this strange sleeping habit to prevent it being swept away by strong currents while helping provide shelter from predators.
It may also prevent damage to the fish from sleeping on the abrasive substrate where they are also at risk from ectoparasites such as gnathiid isopods known to feed on fish sleeping on the sea bed.
Amanses scopas grows to around 20cm/8" and is resident to the Indo-Pacific where it is known to be a shy resident of coral reefs, feeding on coral polyps. It gets its common name from the brush like spines or setae it possesses just in front of its tail.
For more information, see the paper : G.Eyal, L Eyal-Shaham and Y.Loya (2011) 'Teeth-anchorage': sleeping behaviour of a Red Sea filefish on a branching coral. Coral Reefs DOI: 10.1007/s00338-011-0766-y
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.