Often found solo, except during the summer months full moons, the solitary goliath groupers live in the tropical and subtropical waters of the Atlantic Ocean, typically in the shallows close to coral reefs, wrecks or ledges ranging from five to 50m in depth. Recognised as a 'critically endangered' species by the World Conservation Union, these massive creatures play a vital role in the ecological health of their habitats. If you want to learn a thing or two (or ten) about this grumpy-looking group, then read on for our top ten facts on goliath groupers.
Goliath by name, goliath by nature
As its name suggests, the goliath grouper (Epinephelus itajara) is, well, a goliath. Huge. As the largest grouper in the western Atlantic, their size ranges from that of a small child to a Volkswagen Beetle (or, in normal metrics, up to eight feet in length) and up to 800lb.
A grumpy group
Goliath groupers are thick and muscular, covered in brownish-yellow and greenish-grey hues, with irregular, mottled patterns that provide excellent camouflage among the rocky and coral habitats they frequent. They are known for their grumpy-looking
Apex predators
Due to their huge size, Goliath groupers are apex predators within their habitats, meaning that they have no significant natural predators once they reach adulthood. Consider their menu of various crustaceans (including shrimps, crabs and spiny lobsters), octopus and young sea turtles an all-you-can-eat buffet.
Ecological maintenance
Given their apex predator status, an obvious fact about goliath groupers is their importance and vital role in maintaining coral reefs. Their varied diet of various fish, crustaceans and other marine organisms allows them to regulate the populations of these species, preventing any single species from dominating and potentially disrupting the ecosystem balance by overgrazing on the coral or seagrass.
Mangrove dwellers
Before goliath groupers reach their adult size and weight, the process to get there is, unsurprisingly, quite slow. At birth, they hatch (from eggs) as tiny larvae, just a few millimetres long. As they have no maternal protection, these teeny tiny groupers must fend for themselves. They live among mangrove systems for the first four years, using the dense root system as protection from larger fish. Around their fourth birthday - goliath grouper adolescence - they are roughly four feet long, meaning they can leave the mangrove habitat and join other adults among the coral reefs.
Ambush hunters
Despite their appearance, Mother Nature ensured goliath groupers were effective ambush hunters. Their brownish, blotted appearance allows them to camouflage against the rocky terrain where they sneak up on smaller fish and, in one quick movement, suck the prey into their enormous mouths like a vacuum. They don't even chew their food, just suck it down. Charming.
Territorial
Since we're on the topic of their mouths, it makes sense to mention how they utilise their impressive mouthful as a form of self-defence. As territorial creatures, goliath groupers can often be seen opening and closing their mouths, shaking their thick bodies and emitting a loud booming sound with their swim bladder to ward off enemies.
Distinct spawning sounds
Besides emitting booming sounds to ward off enemies, male goliath groupers have also been heard making them during the spawning period. As the groupers engage in broadcast spawning, the sound is believed to attract females to coordinate the release of eggs and sperm. In fact, they synchronise their spawning period with the lunar cycle, which occurs during the summer months (from July to September) and can be seen in groups of 100 on a full moon. How about that for a fact about goliath groupers?
Solo swimmers
The spawning period is also the only time you'll encounter multiple goliath groupers. They prefer to spend most of their time solo, lurking among the coral reefs or slinking in the shadows of wrecks, waiting for small fish to come close and become a quick snack.
If you enjoyed this blog you may also enjoy our Top Ten Hammerhead Shark Facts, Top Ten Coral Facts and Top Ten Turtle Facts
