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12 Fish With Big Foreheads – Fatheads of the Sea

Love funky-looking fish? Then you’ll flip for these big-headed beauties! 

This article explores fish with big foreheads. Learn why these quirky fish evolved huge cranial bulges that make them unforgettable. Whether you’re a snorkeler, diver, or aquarist, you’ll get a kick out of these 15 fish with big foreheads.

Flowerhorn Cichlid – Big-headed Beauties of the Aquarium

Flowerhorn cichlid fish.

The most prized fish with a big forehead is the flowerhorn cichlid. Aquarists love them for their huge forehead protrusion, known as a kok. The fish are also known for their large lips.

Native to South America, flowerhorns were developed in Malaysia in the 1990s through selective breeding of cichlid species. Their forehead growth is a desired trait, and breeders aim to produce flowerhorns with increasingly larger and more pronounced foreheads.

These fish can grow up to 12 inches long, and a mature male’s kok can take up nearly a third of its entire body size. The kok starts small and then grows more prominent as the fish ages. It is thought to help attract mates and establish dominance over other males.

Flowerhorns are aggressive, territorial fish best kept alone or with larger tankmates that can hold their own. Their pearlescent bodies and fierce personalities make them a favourite showcase fish.

Red Cap Oranda – Blazing Red Helmeted Goldfish


The red cap oranda is a breed of goldfish recognisable by its prominent wen or headgrowth. The red cap oranda is a variety with a striking cherry red patch on top of its wen. 

Like all goldfish, orandas originated from China and were bred from Prussian carp. Their headgrowth is composed of fatty tissue and makes up nearly half the size of their body. 

The wen develops as the fish matures, beginning as a slight bulge between the eyes. Selective breeding has produced orandas with foreheads so large that they impair the fish’s vision and mobility. 

Red cap orandas are one of the more popular aquarium strains due to their distinct crimson markings. They come in various sizes and require at least a 20-gallon tank with weekly water changes to stay healthy.

Asian Sheepshead Wrasse – Sex Morphing Marvels

ふうけ, CC BY-SA 4.0, via Wikimedia Commons

The Asian sheepshead wrasse is one goofy-looking fish with a big forehead. They also have thick, fleshy lips, making them unmistakable. This fish inhabits coral reefs in the Indo-Pacific region, using its hard mouth to scrape algae and invertebrates from the rocky seafloor. Its scientific name, Semicossyphus, means “half sheep head” in Greek, referring to its protruding lips.

Male Asian sheepshead wrasses can reach 39 inches long and develop a tall nuchal hump on their forehead. This fatty deposit protects them from rivals during aggressive displays. 

Like many wrasse species, sheepheads start life as females and then change sex to males as they mature. Their transformation finishes with the growth of the characteristic hump. This growth makes them appear top-heavy as they patrol the reefs for food.

Humphead Glassfish – Translucent Wonders of the Reef

Puchatech K., CC BY-SA 3.0, via Wikimedia Commons

With its bulbous transparent head, the humphead glassfish lives up to its name. This tiny fish grows no longer than 3.9 inches, but its vast, rounded forehead makes it stand out. It lives in schools in the Indo-Pacific, feeding on plankton and small crustaceans. 

The purpose of the enlarged forehead has yet to be fully understood. It houses an air-filled cavity that may help the fish detect pressure changes and avoid predators. 

The forehead shrinks when the fish is removed from the water or swimming at different depths. Males also use their hump during mating displays to impress females. The humphead glassfish’s unique looks make it a popular addition to small marine aquariums.

Dolphinfish – A Fisherman’s Dream Catch

Dolphin fish.

More commonly known as mahi-mahi or dorado, the dolphinfish has a protruding bulbous forehead that becomes more prominent in mature males. They are found worldwide in tropical and subtropical waters near the ocean surface. Dolphinfish are fast-growing, reaching 3 feet in length and weighing over 40 pounds in less than a year.

The male’s forehead bulges once it transitions from female to male between 4-6 months old. The fatty deposit on its head continues growing as the fish ages. 

Dominant mature males have the largest foreheads, which protect them from rivals when fighting over females. Dolphinfish are prized sports fish known for their acrobatic fight when hooked. Their meat is savoury, making them a popular restaurant dish.

Green Humphead Parrotfish – The Green Giant of the Reef

Green hump head parrotfish.

With a steep forehead profile, green humphead parrotfish get their name from the parrot-like beaks they use to bite coral and scrape algae. The green humphead parrotfish inhabits coral reefs in the Indian and Pacific Oceans, growing over 4 feet long. It uses its hard beak to gnaw dead coral into fine sand, producing several hundred pounds of sand annually!

This fish looks completely different as a juvenile, with drab brown colouration and no protruding foreheads. Around four years old, they mature into the green phase males with bulging light green foreheads and bright green bodies. 

The forehead may help males assert their dominance in mating hierarchies. This species is vulnerable due to overfishing, habitat loss, and slow population growth.

Napoleon Fish – Emperor of the Coral Reefs

Napoleon fish.

Reaching over 7 feet long and weighing 400 pounds, the Napoleon fish is a gentle giant with a commanding presence in coral reefs. Its broad protruding forehead, fleshy lips and big mouth make it almost look like it is wearing a mask. 

Juveniles have grey colouration with bright blue lines on their forehead bulge. As they mature, Napoleon fish develop tan to purplish-blue bodies with faint blue stripes.

The large forehead houses an air cavity that allows the Napoleon fish to produce low-frequency sounds for communication. Their impressive size deters most predators, though large sharks still threaten them. Napoleons are usually solitary and wary of divers. 

Unfortunately, this fish is endangered due to overfishing for food and the aquarium trade. Only licensed fishermen can collect them in regulated quotas in some countries now.

Redhump Eartheater – Blazing Beauties of the Amazon

Хомелка, CC BY-SA 3.0, via Wikimedia Commons

The redhump eartheater is a South American cichlid named after the tall, bulbous fatty hump that develops on its forehead as it matures. Most cichlids have an organ on their heads called a nuchal hump. 

It is a fat storage reserve and dominant males typically have the largest humps since they control the best feeding and spawning territories. 

Juvenile eartheaters have small humps that grow larger as males age and ascend the social hierarchy. The hump’s red colouration helps to attract females and intimidate rival males. 

Steephead Parrotfish – Jewels of the Reef

Rickard Zerpe, CC BY 2.0, via Wikimedia Commons

The steephead parrotfish inhabits Hawaii, Johnston Atoll, and the Pitcairn Islands coral reefs. Named for its vertical forehead profile that flares out from its pointy beak-like snout. This large fish can reach lengths over 3 feet, though it is rare due to extensive overfishing. 

Mature males develop a tall, bulbous forehead that can take up nearly a third of their entire body length. It is likely a protective shield when they ram together during aggressive displays. 

Females and juveniles lack this pronounced bulge. These fish with big heads play an important role in reef health by feeding on algae and fragmenting dead coral skeletons into fine sand.

Humphead Cichlid – Striped Wonders

Bjoertvedt, CC BY-SA 4.0, via Wikimedia Commons

A member of the African Rift Lake cichlid family, the humphead cichlid lives up to its name with an enlarged fatty forehead deposit. It is native to Lake Tanganyika, the second-deepest lake in the world. Males develop a nuchal hump as they mature and compete for breeding territories in the rocky lakebed. 

The size of the fatty forehead correlates with the male’s social status. Dominant, healthy alpha males have substantially larger humps than lower-ranking fish. Females prefer to mate with alphas who have proven they can secure prime habitats and avoid predators. 

Humphead cichlids occasionally enter the aquarium trade, though their aggression makes them best suited for experienced keepers.

Blue Dolphin Cichlid – Majestic Blue

Fish with a big forehead blue dolphin cichlid.
Brian Gratwicke, CC BY 2.0, via Wikimedia Commons

The blue dolphin cichlid is a stunning fish with big eyes, stocky elongated body and a pointed snout that resembles a dolphin, hence its name, blue dolphin cichlid. This species can grow up to 10 inches (25 cm) in length and sometimes even larger in an aquarium. They can live up to 10 years with proper care, making them long-term commitments for aquarists.

The blue dolphin cichlid has an overall blue colouring with varying amounts of black markings on their fins and back, depending on their place of origin. Both males and females develop a lump on the forehead as adults.

Green Terror – Beauty and Aggression

Fish with a big forehead green terror.
5snake5, CC0, via Wikimedia Commons

Despite its alarming name, the green terror cichlid has a gentler temperament that belies its appearance. Native to South America, it gets its name from the distinctive fleshy lump on its forehead that develops as males mature. Ranging in colour from grey to green to red-orange, this fish can reach 10 inches in captivity.

The nuchal hump starts out small on juveniles, then grows more prominent on adult males, particularly dominant territorial ones. It likely serves as fat storage and a physiological signal of fitness for potential mates. Despite being called a terror, this fish does fine in community tanks as long as tankmates are close to their size and not too small or passive.


What is the name of the fish that has a big head?

Some of the most well-known fish with enlarged heads include the flowerhorn cichlid, red cap oranda goldfish, Asian sheepshead wrasse, humphead glassfish, dolphinfish or mahi-mahi, green humphead parrotfish, Napoleon fish, and the redhump eartheater.

What is the big fish with a bulbous head?

The Napoleon fish has an enormous, bulbous head that protrudes from its body. It is one of the largest reef fish, reaching sizes over 7 feet long and weighing up to 400 pounds. Its forehead houses an air cavity that allows it to make low-frequency sounds.

Why do some fish have big foreheads?

There are a few theories on why certain fish evolved prominent foreheads or humps. In some species, like cichlids, the fatty forehead deposit stores nutrients and energy reserves. It also serves as a signal of social status, with dominant males having the largest humps. The forehead may help absorb impacts during fighting. It could also make males look larger than competitors and more attractive to females.

What is the name of the Japanese big forehead fish?

The Japanese fish with an enlarged forehead is likely the Asian sheepshead wrasse, known in Japan as “yoriko”. This reef fish’s thick, fleshy lips and prominent forehead make it easy to identify. Males grow a tall nuchal hump on their foreheads to assert their dominance on the reef.

What is a goldfish with a big forehead called?

The oranda is a breed of goldfish recognised by its prominent wen or headgrowth. The wen starts small and then expands as the fish matures, eventually covering a good portion of the oranda’s head and body. Selective breeding has produced orandas with very enlarged head growths.

What tropical fish has a big bump on its head?

Many tropical fish develop forehead bumps, including the flowerhorn cichlid, redhump eartheater, green terror cichlid, humphead cichlid, and frontosa cichlid. These fatty deposits on the head are called nuchal humps. They serve as energy reserves and signal dominance in male cichlids and related species.

What kind of fish has big lips and foreheads?

Fish like the Asian sheepshead wrasse and Napoleon fish have pronounced lips and foreheads. Their large, thick lips likely help them scrape algae and invertebrates from reefs to eat. The enlarged forehead may help absorb impacts during territorial fights or allow males to make loud, low-frequency noises.