John Dory, or Zeus faber as it is known scientifically, is a distinctive fish and easy to recognize. It has a thin, deep compressed oval body with 9 to 10 extended spines on its dorsal fin and then narrows at the rear end to 4 spines on its anal fin. John Dory have sharp microscopic scales that run around its body towards the back between the dorsal and anal fins. Their pelvic fins are extended with long rays and are usually slightly darker in color to the rest of their body. John Dory can grow to around 66cm in length and around 3kg in weight. They have massive heads, with their large eyes set high near the top of the head. They also have large and wide extendable mouths. One of the most distinctive characteristics, along with the mouth and shape of the John Dory is the dark spot in the middle of their bodies that resembles a target. This is set back, and slightly higher than the pectoral fin, and is ringed by a narrow yellow halo. This large ‘eye’ confuses its prey and helps ward off its own predators and is often referred to as the thumbprint of St Peter. John Dory’s colouration is usually yellowish to olive-brown with silvery sides but they can also have wavy yellow-brown stripes. The entire fish has an almost metallic-like sheen to it when seen out of the water.
HABITAT & FEEDING
John Dory are carnivorous fish found on weed lines and kelp beds in deeper waters usually around 6-15m of water although they have been caught around the 150 metre mark. They are found in the warm waters around the North Island of New Zealand - most commonly north of the Bay of Plenty – and are caught all year-round. John Dory are very poor swimmers and so rely heavily on their highly effective camouflage and stealth to stalk their prey. They eat a variety of small fish such as sardines, baitfish and occasionally small squid and cuttlefish. Their camouflage and stealth compensates for their lack of speed – once they have snuck up on their prey they engulf it with their large extendable, protuberant mouths. Their effectiveness at camouflaging themselves also helps hide them from bigger predators such as sharks and other larger pelagic fish which prey on them. The large dark spot in the middle of their body is believed to aid in their defence against predators – by turning side on to the attacker – the large spot mimics an eye, which can scare off larger fish. They are not normally found in schools and, being a solitary fish, are almost always encountered on their own.
AGE & GROWTH
John Dory usually breed in late spring and summer, with a rapid growth rate, so that by the second winter, individuals can normally reach 25cm. After they are three or four years of age, they are usually ready to reproduce. This happens around the end of winter. John Dory are substrate scatterers, which means that they release sperm and eggs into the water to fertilize. The typical lifespan of a John Dory is around 12 years in the wild.
John Dory offer excellent eating quality. They have medium to firm, pearly-white flesh with beautiful flavour and a fine grain, which is suitable for most if not all cooking methods. John Dory is high in Omega-3 levels and, once filleted, is bone-free.