Peacock grouper

The peacock grouper (Cephalopholis argus) is named after its pattern: its dark brown-green body is covered in tiny, black-rimmed, brilliant blue dots like the eyespots of a peacock feather. The scientific name points the same way: Argus was the hundred-eyed watchman of Greek mythology. Depending on its mood the fish can also flash paler vertical bars on the rear half of its body – this "costume change in seconds" is classic grouper communication.

It is a typical ambush predator, most active at dawn and in the late afternoon when it hunts smaller fish – mainly surgeonfish and damselfish – with lightning-fast rushes. It is territorial: a big male can rule a patch of reef of up to two thousand square metres, which the females of his harem divide into smaller districts. The male tours his kingdom daily, "checking in" with each female through a short ritual of side-by-side swimming.

Around Hurghada you meet it in the shadowy corners of coral plateaus and walls: it is regularly seen hovering under ledges or stalking between the coral heads at Umm Gamar, on the Abu Ramada walls and in the Giftun coral gardens. It is warier than its red cousin the coral hind, but a slow, calm approach makes it very photographable. It occasionally turns up on the shallower reef tops while you snorkel too.