John Dory, also known as St Pierre, refers to fish of the genus Zeus, especially Zeus faber, of widespread distribution. It is an edible deep-sea fish with a laterally compressed olive-yellow body which has a large dark spot, and long spines on the dorsal fin. The dark spot is used to flash an 'evil eye' if danger approaches the John Dory.
Various explanations are given of the origin of the name. It may be an arbitrary or jocular variation of dory (itself from the French dorée, gilded), or perhaps an allusion to John Dory, the hero of an old ballad. Others suggest that "John" derives from the French jaune, yellow. The novel An Antarctic Mystery by Jules Verne gives another account, which has some popularity but is probably fanciful: "The legendary etymology of this piscatorial designation is Janitore, the "door-keeper," in allusion to St. Peter, who brought a fish said to be of that species, to our Lord at His command." (St. Peter is said to be keeper of the gates of Heaven.) A related legend says that the dark spot on the fish's flank is St. Peter's thumbprint. The John Dory grows to a maximum size of 65cm (25.6") and 3kg (6.6lb) in weight. It has 10 long spines on its dorsal fin and 4 spines on its anal fin. It has microscopic, sharp scales that run around the body. The fish is an olive green color with a silvery white belly and has a dark spot on its side. Its eyes are near the top of its head. It has a flat, round body shape and is a poor swimmer.
The John Dory is the top predator in its habitat. It usually gets its food by stalking it then shooting out a tube in its mouth to capture its prey. The John Dory eats a variety of fish, especially schooling fish, such as sardines. Occasionally they eat squid and cuttlefish.
Their predators are sharks, like the dusky shark, and other large bony fish. John Dory are found on the coast of South West Africa, South East Asia and Australia, the coasts of Japan, and on the coasts of Europe. They live near the seabed, living in depths from 5 meters (16') to 360 meters (1181'). They are normally solitary.
After they are 3 or 4 years of age they are usually ready to reproduce. This happens around the end of winter. They are substrate scatterers, which means that they release sperm and eggs into the water to fertilize. Typical lifespan is about 12 years in the wild.