The giant grouper (Epinephelus lanceolatus), also known as the Queensland grouper, brindle grouper or mottled-brown sea bass, is a species of fish from the subfamily Epinephelinae which is part of the family Serranidae. The family Serranidae also includes the anthias and sea basses.
Giant groupers are the most widely distributed species of grouper in the world, and are found in the Indo-Pacific. They reside in shallow waters, at depths of 1 to 100 metres (3.3 to 328.1 ft). These fish eat a variety of other fishes, as well as small sharks and other marine animals.
These fish are solitary animals and protogynous hermaphrodites. The giant grouper is listed as Data Deficient on the IUCN Red List, but some other species, such as the Atlantic goliath grouper, are critically endangered, so we can assume the population of the giant grouper is declining. The biggest threats to these animals are overfishing and habitat loss.
Giant Grouper Characteristics
Giant groupers are large fish, which can measure around 180 centimetres (71 in) long, although some have measured up to 270 centimetres (110 in). The maximum recorded weight for one of these groupers is 400 kilograms (880 lb), although 363 kilograms (800 lb) is more common.
They have a thick, robust body that is greyish-brown in color with a mottled pattern and darker fins. Juveniles are yellow with wide, dark irregular bars and irregular dark spots on their fins. They have small eyes and a large mouth with needle-like teeth.
Giant groupers have 11 spines and 14 to 16 soft rays in the dorsal fin while the anal fin has 3 spines and 8 soft rays. Their caudal fin is slightly rounded.
Giant Grouper Lifespan
Giant groupers have a long lifespan, living for an average of 37 yeas. Some, however, can live for up to 100 years old.
Giant Grouper Diet
Giant groupers are carnivores and eat a wide variety of fishes, but will also eat small sharks, juvenile sea turtles, crustaceans and molluscs. Giant groupers eat their prey whole instead of chewing, using their very large mouths to create enough negative pressure to suck in whole fishes or large invertebrates.
They are opportunistic ambush predators. These fish can swim at speeds of up to 78 mph (125 kmph) if they need to, but most of their prey is slow-moving.
Giant Grouper Behavior
The giant grouper is a solitary animal for most of its life. They are, however, curious animals and will approach divers. While they are not considered a threat to humans, divers are advised not to try to touch them or feed them.
Giant groupers can communicate using their mouths by creating a deep rumble that travels through the water. This is done to communicate with other groupers, as well as to guard its own territory.
Giant Grouper Reproduction
Giant groupers are, like other groupers, protogynous hermaphrodites. This means that they first function as females and later transform into males. They congregate in a spawning location with groups of around 100 fish, and the males release their sperm at the same time as the females release their eggs.
They release their eggs and sperm into a water column that stands above a relatively deep reef, allowing the eggs to fertilize before descending deep into the reef so they are not threatened by predators. Neither male nor female groupers play a part in raising their young.
Giant Grouper Location and Habitat
Giant groupers have wide distribution across the Indo-Pacific and are the most widely distributed species of grouper in the world. They can be found from the Red Sea and the eastern coasts of Africa as far south as Algoa Bay in South Africa and across the Indian Ocean into the Western Pacific Ocean as far east as the Pitcairn Islands and Hawaii. They can also be found as far north as southern Japan and as far south as Australia.
These fish usually reside within reefs and are actually the largest known bony fish found on reefs. They can be found in caves and in wrecks, with adults holding and defending territories. They prefer shallow waters, at depths of 1 to 100 metres (3.3 to 328.1 ft).
Giant Grouper Conservation Status
The conservation status of the giant grouper is unknown, and they are listed as Data Deficient on the IUCN Red List. However, other species of grouper, such as the Atlantic goliath grouper, are listed as Critically Endangered, and some species, such as the Red Grouper, are listed as Near Threatened.
Therefore, we can make assumptions that the giant grouper population may also be in decline. The main threats to the giant grouper are overfishing and habitat loss.
The giant grouper is a highly valued food fish and is taken by both commercial and recreational fisheries. It is valued in Hong Kong as a live fish for the live reef food fish trade.
Giant Grouper Predators
Because the giant grouper is so large, it does not have many natural predators. Young groupers could be taken by large fish such as barracuda, king mackerel and moray eels, as well as other groupers.
Giant Grouper FAQs
Are giant groupers really giant?
Giant groupers aren’t exactly giant, but they are huge! They’re bigger than humans, and can measure up to 270 centimetres (110 in). That’s over 9 feet long! They are also very heavy, weighing as much as 400 kilograms (880 lb).
Where do giant groupers live?
Giant groupers prefer the tropical shallow waters of the ocean, around rocks and reefs. They live quite close to the surface, between 1 to 100 metres (3.3 to 328.1 ft) deep.
Can giant groupers harm humans?
Giant groupers are not known to be aggressive animals. In fact, they they have been called “gentle giants” in the past. They are quite curious animals and will often swim up to divers. However, it is unknown how giant groupers may react when touched by humans, so it is advised that you do not touch or try to feed one. They are very big and could cause harm if they wanted to!
Other Grouper Species
There are 159 species of grouper within the subfamily Epinephelidae. Here are some of the most common grouper species.
Atlantic Goliath Grouper
The Atlantic goliath grouper (Epinephelus itajara), formerly known as the jewfish, is found in the Atlantic ocean, ranging from northeastern Florida, south throughout the Gulf of Mexico and the Caribbean Sea, and along South America to Brazil.
This grouper is thought to be the largest species of grouper, with most measuring up to at least 2.5 meters (8.2 feet) and weighing up to 363 kilograms (800 pounds). It is brownish yellow to gray to greenish in color and has small black dots on the head, body and fins.
The Atlantic goliath grouper is listed as Vulnerable on the IUCN Red List. The main reasons for the decline in its population are overfishing and the exploitation of spawning aggregations.
The red grouper (Epinephelus morio) is found in the western Atlantic Ocean. They are around 50 centimetres (20 in) in length and have a weight of 23 kilograms (51 lb). The upper part of their body is dark reddish brown, and their underparts are paler pink. They have light splotches across their body.
These fish actively excavate pits in the seafloor and do so throughout their life. They create exposed surfaces on which sessile organisms, such as sponges, soft corals and algae, actively settle.
The red grouper is listed as Vulnerable on the IUCN Red List. Their main threats are overfishing and habitat loss.
The black grouper (Mycteroperca bonaci), also known as the black rockfish or marbled rockfish, is found in the western Atlantic Ocean from the northeastern United States to Brazil, around rocky bottoms and coral reefs at depths of 10 to 30 metres (33 to 98 ft).
It is normally around 70 centimetres (28 in) in length and around 100 kilograms (220 lb) in weight. It is an olive gray color is marked with dark blotches and brassy hexagonal spots over the head and flanks. Its pectoral fins are sooty brown and fade to orange towards the margin.
The black grouper is listed as Vulnerable on the IUCN Red List. It is often fished for its meat, and is further threatened due to the fact it is a relatively slow breeder.
The snowy grouper (Hyporthodus niveatus) is found in the eastern Atlantic Ocean, at depths between 10 and 525 metres (33 and 1,722 ft) over rock substrates in offshore waters.
It is around 60 centimetres (24 in) long and weighs around 30 kilograms (66 lb). It is dark brown with a black margin to the spiny part of the dorsal fin.
The snowy grouper is listed as Vulnerable on the IUCN Red List, largely due to overfishing. In the US, the snowy grouper is protected and may only be fished during certain months of the year. There is also an annual catch limit for this fish.
The Warsaw grouper (Hyporthodus nigritus) is found in the Western Atlantic from Massachusetts to the Gulf of Mexico, Cuba, Trinidad, and south to Brazil. It is classified as a deep-water grouper, because it inhabits reefs on the continental shelf break in waters 180 to 1700 ft (55 to 525 m) deep.
These fish can exceed 8 ft in length and have been known to weigh 350 pounds (160 kg). They are dark reddish-brown or brownish-gray to almost black in color dorsally, and dull reddish-gray ventrally.
The Warsaw grouper is listed as Near Threatened on the IUCN Red List. It is threatened by fishing or by catch release mortality (due to pressure change).
The Gulf grouper (Mycteroperca jordani) is found in the eastern Pacific Ocean where it is endemic to Mexican waters from San Carlos, Baja California Sur south to Mazatlán. It resides at depths between 5 to 30 metres (16 to 98 ft) but has been recorded as deep as 45 metres (148 ft) during the summer months.
This grouper can reach up to 198 centimetres (78 in) in length and reach a weight of 91 kilograms (201 lb). They are usually dark brown or gray in color, although they have the ability to quickly change color and adopt a pattern resembling that of juveniles.
The Gulf grouper is listed as Endangered on the IUCN Red List. They are considered to be one of the most valuable groupers caught in the Gulf of California by commercial and recreational fisheries, and this has led to a decline in their population.
The Nassau grouper (Epinephelus striatus) is found in the western Atlantic Ocean and around the Caribbean Sea, from Bermuda, Florida, and the Bahamas in the north to the eastern coast of Venezuela. It resides from the shoreline to nearly 100 meters deep.
This grouper is one of the largest fish to be found around coral reefs. It can grow over a meter in length and up to 25 kg in weight. The color of this grouper depends on how deep it lives. In shallow water (down to 60 ft), it is a tawny color, but specimens living in deeper waters are pinkish or red, or sometimes orange-red in color. They are also often covered in lighter stripes, darker spots and other patterns.
The Nassau grouper is listed as Critical on the IUCN Red List. The current population is estimated to be more than 10,000 mature individuals, but is thought to be decreasing. The main reason for their decline is loss of habitat, particularly coral reefs, and overfishing and fishing during the breeding period.
The dusky grouper (Epinephelus marginatus), also known as the yellowbelly rock cod or yellowbelly grouper, is found in the Mediterranean Sea and North Africa coast. It also occurs in the south western Atlantic, around rocky reefs from surface waters down to 300 metres in depth.
It can grow up to 150 cm in length, but is more commonly around 90 cm in length. Its head and upper body are colored dark reddish brown or grayish, and it has pale greenish yellow, silvery gray or whitish blotching on top.
The dusky grouper is listed as Vulnerable on the IUCN Red List. This is down to the fact it is a popular food fish and heavily caught across its range. It also grows slowly, which makes it vulnerable to over-exploitation.
The blacktip grouper (Epinephelus fasciatus), also known as the redbanded grouper, blacktipped cod, black-tipped rockcod, footballer cod, red-barred cod, red-barred rockcod, scarlet rock-cod or weathered rock-cod, is found in the Indo-Pacific region, from 15 m up to 160 m. This grouper can be more sociable than other groupers, and is sometimes found in groups of 10 to 15 individuals.
This grouper is around 22 centimetres (8.7 in) in length and has a weight of around 2 kg (4.4 lb). Its color ranges from pale greenish gray to pale reddish yellow, to scarlet.
Unlike most species of grouper, the blacktip grouper is listed as Least Concern on the IUCN Red List.
The coral grouper (Cephalopholis miniata), also known as the coral hind, coral rock cod, coral cod, coral trout, round-tailed trout or vermillion sea bass, is found in the Indo-Pacific. It resides at depths of 2 to 150 metres (6.6 to 492.1 ft), around coral reefs and often in caves and below ledges.
This grouper is orange-red to reddish brown in color, and has many small bright blue spots that cover the head, body and the dorsal, anal and caudal fins. It can measure up to 50 centimetres (20 in) long.
The coral grouper is listed as Least Concern on the IUCN Red List. It is an important species in commercial fisheries at the local level. It is also a popular public aquarium fish because of its bright colors.