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Home › Ocean Life › Marine Animals › Vertebrates › Groupers

Interesting Facts about Groupers

[Phylum: Chordata] [Class: Actinopterygii] [Order: Perciformes] [Grouper Family: Serranidae]

No matter whether you're researching the best type, the rarest, the most common, or the biggest, we found more than 160 different species of grouper.

This section contains fun facts and interesting information about grouper fish, including where they live, what they eat, and how they reproduce.

Grouper Fish Habitat & Geographical Range

It's true to say that these top level predators inhabit most warm water environments around the world, especially:

• Arabian Gulf (aka the Persian Gulf)
• Caribbean and parts of the Yucatan Peninsula
• Egyptian Red Sea
• WIO and South East Asia (SEA)

The best place for scuba divers to see groupers is around rock clusters and large reef structures near the ocean floor.

Fun Fact: It seems the origins of the name for grouper species comes from the South American Portuguese word "garoupa". But, other names include groper in Australia and "hammour" in some areas of the Middle East.

Grouper Fish Characteristics and Behaviour

Groupers fish belong to a diverse group of ray-finned fishes known as "teleostei". In general, they are a stout fish with a broad head, large mouth, high set eyes, and a heavy body.

Most of the species have dull body colouring, with various hues of green and brown. But, others display bright and bold patterns, especially the red grouper (Epinephelus morio) that lives in deep water environments - approaching 180 metres (600 feet).

Grouper Size and Weight

The giant grouper fish (Epinephelus lanceolatus), often called the bumblebee grouper, can grow over one metre in length and some can weigh over one hundred (100) kilograms (220 pounds).

The Atlantic goliath grouper (Epinephelus itajara) is the largest of all, weighing more than 400 kilograms, and the smallest is the coney (Cephalopholis fulva) weighing less than half a kilogram.

These factors contribute to their general "slow and lazy" demeanour when swimming around the rocks and reefs of oceanic benthic zones.

Are Groupers Dangerous to Humans?

As a matter of fact, no! But, due to their gigantic size, these carnivores often appear threatening and fearsome. In truth, groupers are quite a timid fish. Even so, the males are big and brave enough to defend their territory if they feel threatened.

Pro Tip: If you're wondering what animal kills the most humans in the world, it is definitely not any of the grouper fish species!

What Do Grouper Fish Eat?

You don't need to get close to a grouper fish to see that it has an enormous mouth and some teeth. Yet, they use bony tooth plates at the back of the throat (pharynx) and their powerful jaws to crush prey to death - rather than biting it.

Using the width of their mouth, and the strong gill muscles, they create a suction system that draws food into their throat. In actual fact, they usually swallow food whole - instead of ripping pieces from it.

By and large, the favourite daily diet for most grouper species will include slow-moving fishes, and:

• Crustaceans
• Lobsters
• Octopus
• Red lionfish (Pterois volitans)
• Sea turtles
• Small sharks
• Squid
• Zooplankton

Interesting Fact: This feeding technique is so powerful, groupers often suck their victim into their mouth from a significant distance away. They actually use the same "sucking system" to shift and remove sandy substrate from their shelter.

Types of Grouper Fish Species

How Do Groupers Reproduce?

Not only are grouper fish protogynous hermaphrodites (practice sequential hermaphroditism), but they also live in a monandric relationship.

Put another way:

They all function as females from birth. They transform into males as they grow older, and usually mate with only one sexual partner. Hence, groupers change gender from females to males during their early development or later in their adult life cycle.

Reaching sexual maturity can take as little as a few months or several years. The average grouper lifespan is thirty years in the wild. Yet, the goliath or "jewfish" specimen can grow to be fifty (50) years old.

Here's the thing:

In general, the breeding season occurs in the summer months when the water gets warmer. Even so, the Nassau grouper breeds at a full moon during the cold winters.

It's not uncommon to see large formations of groupers fish gathering together during the breeding rituals. In fact, some aggregations may contain several thousand members.

After the females have released their eggs, the males will release sperm into the water column. As a consequence, fertilised eggs get swept away by oceanic currents as they become part of the zooplankton. Within a few days, the eggs will hatch.

Grouper Predators and Threats

There are several reasons why the general populations of groupers worldwide is in serious decline. Typical threats to their long term survival include overfishing, habitat destruction, and being:

• Targeted by free diving spearfishers and deep sea anglers.
• Easy prey for apex predators, such as:
  • Barracudas
  • King mackerels
  • Moray eels
  • Sharks
  • Large groupers (yes they are cannibalistic creatures)
• Prime food fishes for human consumption (e.g. despite carrying toxic substances that can cause ciguatera fish poisoning).

Important: The IUCN Red List of Threatened Species is a comprehensive source of information about the global conservation status of animals, fungi, and plants. For example, in 2018 the IUCN listed the moustache grouper as Least Concern (LC) and the Nassau grouper as Critically Endangered (CR) and decreasing in numbers.

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