John Dory, a striking marine fish known scientifically as Zeus faber, is celebrated not only for its unique appearance but also for its culinary appeal. Found in the coastal waters of the eastern Atlantic, Indian and western Pacific Oceans, this fish is easily identifiable by its laterally compressed body, which features a prominent dark spot on each side.
With its long dorsal spines and large, expressive eyes, the John Dory has become a subject of fascination for both anglers and chefs.
What is John Dory?
John Dory is a distinctive marine fish found in the coastal waters of the eastern Atlantic, Indian and western Pacific Oceans. It belongs to the Zeidae family, with the most common species being Zeus Faber.
Furthermore, John Dory is a highly regarded fish known for its delicate flavour and versatility in the kitchen. Its white, meaty flesh is firm yet flaky, making it suitable for various cooking methods, including pan-frying, grilling, baking and poaching. The fish’s mild, slightly sweet taste and moist, succulent texture appeal to seafood lovers.
When preparing John Dory, it is best to keep the skin on during cooking to protect the delicate flesh. The fish pairs well with lemon juice, butter and robust flavours like harissa or Mediterranean spices. It also works well in seafood stews and bouillabaisse.
ALSO READ: Flame Point Siamese Cats: Feline fusion of rarity, beauty, affection
Appearance
John Dory has a laterally compressed, oval-shaped body that is olive-yellow to brown. Its body is so thin that it can hardly be seen from the front, giving it a unique flat appearance. One of the most distinctive features of the John Dory is the large, dark spot on each side of its body. This spot is believed to resemble an eye and acts as a camouflage mechanism to confuse prey.
John Dory has long, sharp spines on its dorsal fin, which can extend up to half the length of its body. It has a prominent, upward-facing mouth with sharp teeth, which it uses to catch and grind its prey. The fish’s eyes are located near the top of its head, providing it with binocular vision and depth perception, which are important for predators.
The fish can grow up to 65 centimetres (2 ft) in length and weigh up to five kilogrammes (12 lb). It has microscopic, sharp scales that run around its body. The fish’s fins are typically yellow or white.
John Dory fish
Etymology
The name “John Dory” has long been a source of curiosity and speculation. The term “dory” is derived from the French word dorée, meaning “gilded”, which aptly describes the fish’s golden-hued appearance. The addition of “John” to the name first appeared around 1609, likely influenced by a 17th-century song about a sea captain named John Dory.
Some etymological theories suggest the name may stem from the French jaune dorée (golden yellow) or the Italian gianitore (janitor), but these are largely discredited. A popular legend claims that the dark spot on the fish’s side is St. Peter’s thumbprint. This legend has given rise to the fish’s alternative name, “St. Peter’s Fish”, particularly in Mediterranean countries.
Morphology
John Dory’s distinctive appearance is a result of its adaptation to life near the seafloor. Its laterally compressed, oval body shape, which can reach a maximum length of approximately 65 centimetres (2 ft) and weigh up to five kilogrammes (12 lb), allows it to blend seamlessly with its surroundings. The fish’s colouration, ranging from olive-yellow to brown, with a silvery-white belly, provides excellent camouflage against the seabed.
One of the most striking features of John Dory is the large dark spot on each side of its body. This spot, which may resemble an eye, serves as a form of camouflage and may confuse potential prey. The fish’s eyes are situated near the top of its head, providing excellent binocular vision and depth perception, crucial for hunting.
The fish’s body has microscopic, sharp scales that enhance its streamlined shape, making it appear even thinner from the front. Its long spines on the dorsal fin—ten in total—and four spines on the anal fin serve as a deterrent to predators, although they are not venomous.
Prey and predators
John Dories are carnivorous and primarily feed on smaller fish, particularly schooling species, such as sardines, along with squid and cuttlefish. They employ a unique hunting strategy: stalking their prey and then rapidly extending their jaws to create a tube-like structure that sucks in the fish along with water. This method allows them to capture prey efficiently, utilising their pre-maxillary bone to grind food.
In terms of predators, John Dories are vulnerable to larger bony fish and sharks, such as the dusky shark. They lack significant defensive adaptations, relying instead on their ability to camouflage and their flattened body shape to evade detection. When threatened, the dark spot on their side may mimic an eye, potentially deterring predators.
ALSO READ: Top 15 ugly fishes in the world
Habitat
John Dories inhabit a wide range of coastal waters, including the eastern Atlantic, Indian and western Pacific Oceans. They are typically found at depths ranging from 5 to 360 metres (16 to 1,200 ft), often residing near the seabed on both soft and hard substrates. They prefer environments such as sandy bottoms, muddy fields, rocky formations and reefs. John Dories are generally solitary creatures, although they may be found in small groups during feeding or spawning periods.
Reproduction
John Dories reach sexual maturity between the ages of three and five years. Their spawning season occurs around the winter solstice, during which females scatter their eggs onto the ocean floor while males release sperm in the same area, resulting in external fertilisation. This method, known as substrate scattering, does not involve nest building or parental care. The eggs are non-buoyant and settle to the bottom, where they develop independently.
Lifespan
The typical lifespan of a John Dory in the wild is about 12 years. Males tend to reach maturity at lengths of 23-29 cm, while females mature at lengths of 29-35 cm. Their relatively long lifespan and late maturity make them susceptible to overfishing, particularly in areas where bottom trawling is prevalent, which poses a significant threat to their populations.
How to identify a John Dory
Identifying a John Dory (Zeus faber) involves recognising its unique physical characteristics and understanding its habitat and behaviour. They include:
Body shape and size
John Dory has a laterally compressed, oval-shaped body that can reach lengths of up to 65 cm (approximately 2 feet) and can weigh as much as 5 kg (around 12 pounds). This flattened body shape allows it to blend into its surroundings, making it an effective ambush predator. When viewed from the side, John Dory’s broad body is apparent, but when it turns, it appears almost invisible due to its thin profile.
Colouration
The colouration of the John Dory is one of its most striking features. Its body is primarily a silvery-yellow or olive hue, adorned with horizontal lines that extend from the head to the tail. The most prominent characteristic is the large, dark spot located on each side of its body, which resembles an eye. This spot serves as a form of camouflage, confusing both predators and prey. The belly is typically lighter, transitioning to a silvery-white.
Fins and spines
John Dories are notable for having two dorsal fins, which is relatively uncommon among fish. The first dorsal fin consists of long, spiny rays that can give the appearance of a crest, while the second dorsal fin is softer and shorter. The anal fin also has spiny rays, and both dorsal fins may develop long filaments as the fish matures. The pectoral fins are elongated, further contributing to the fish’s distinctive silhouette.
Facial features
The head of the John Dory is large and features a prominent, upward-facing mouth equipped with sharp teeth. This mouth is adapted for capturing prey, allowing the fish to extend its jaws to create a tube-like structure that sucks in smaller fish and crustaceans. The eyes are large and striking, often appearing bright yellow, which contrasts sharply with the dark iris.
Behavioural traits
John Dories are typically solitary creatures, preferring to lie in wait among rocky substrates and sandy bottoms, where they can ambush unsuspecting prey. They are known to bury themselves in the sand, making them difficult to spot. Their hunting strategy relies heavily on stealth and camouflage as they remain motionless until an opportunity to strike presents itself.
ALSO READ: Skate fish: Uncovering diversity, adaptation technique of unique marine species