Photo copyright Suzanne Challoner.
Taken at Abu Dabab, Egyptian Red Sea.
Also known as a sea cow, Dugongs feed in the seagrass beds of the Indo-Pacific. They are the only herbivorous, truly marine mammal. (The related manatee spends some of its life in fresh water.)
Being a slow swimmer, you'll find dugongs in sheltered lagoons and bays in warm water such as are found in the Red Sea (eg Marsa Alam), East Africa, the Philippines, and Australia. They have dense, massive bones, which help to keep them submerged. Their lungs lie along their back and act like floats, keeping them horizontal in the water. They can eat as much as 40 kg (88 lb) of seagrass a day, leaving distinctive troughs in seagrass meadows.
Dugongs are thought to use the "lek system" whereby males establish and defend courtship territories in traditional areas where females come only to mate.
More pictures of Dugongs are in the Red Sea rooms of our photo gallery.
The Blue Planet, by Alastair Fothergill, Martha Holmes, Sir David Attenborough, BBC Consumer Publishing, 2001, ISBN 056-33-8498-0
The Underwater Photographer: Digital and Traditional Techniques, by by Martin Edge, Paperback, 536 pages (2009)