Groupers around Koh Tao

Marine life Koh Tao - Groupers

Groupers in Koh Tao

There are a number of different types of groupers, and a wide range of them can be found right here on Koh Tao. The most commonly seen when diving Koh Tao are the giant grouper, the black tip grouper, the hexagon grouper and the blue lined grouper.

Origins Of The Name

The name ‘grouper’ originates from the Portuguese name ‘garoupa’ the orgin of which is believed to be from an Indigenous South American language. For those of you that are travelling into Australia after Koh Tao you will hear ‘Groupers’ referred to as ‘Groper’ for several species including the Queensland Grouper.

In the Philippines it is named Lapu Lapu or Pugap and in New Zealand groupers are known as Hapuku. In the middle east the fish is known as Hammour and is widely eaten.

Built To Last!

Groupers typically have a fat body and a large mouth. They are not built for long-distance or fast swimming (just like me!). If I was a fish I would be definitely be a grouper!

Giant Groupers

The giant grouper is the largest of the grouper family that is commonly found around the warm coral reef waters of Koh Tao. It is found from near the surface to depths of 100 m at reefs throughout the Indo-Pacific region. It reaches up to 2.7 m in length and 400 kg in weight, unconfirmed reports of it growing much bigger exist, up to 4.26m.

Giant groupers feed on a variety of marine life, including small sharks and juvenile sea turtles. Its favorite sea food is the spiny lobsters. The giant grouper preys upon other sea life but rather than chasing after its prey, it prefers to lie in wait and catch any prey unaware.


These giants can live up to fifty years in the wild. Due to overfishing of groupers themselves and its slow-swimming, sluggish behavior isn’t good for them if there are spear fishermen around. Another threat is that their habitat is being destroyed by excessive fishing as its prey being wiped out. Similarly, the explosive devices used in reef areas have led to a decline in their population. As their numbers of the species has declined drastically in many regions, it is considered vulnerable, and as a result they are now protected.

A Protogynous Hermaphrodite

They usually breed between May and August and like many other fish they are hermaphrodites. They are a specific type of hermaphrodite known as the protogynous hermaphrodite, this means that the young are predominantly female but turn into males as they grow older. As they grow, groupers turn male and the male grouper has a group of up to fifteen females. If there is no male in the group, the largest female will turn male to satisfy their reproductive needs.

In addition to their possible great size, another defense that some groupers have is the ability to change the colour of their skin. Sometimes this colour change is simple, such as turning from dark to light in order to blend in with varying levels of light. Some groupers have also developed colour patterns composed of stripes, spots, or blotches that help them to blend in with the bottom of coral reef areas.

Where Can You See Groupers Around Koh Tao?

For the best opportunity to see the giant groupers around Koh Tao you will have to head off to the deeper dive sites. The best dive sites to see these giants would be either at Chumphon PinnacleSouth West Pinnacle or Sail Rock. Chumphon Pinnacle is about 40 minutes North west of Koh Tao, it starts 15m below the surface, descending down to a depth of around 40m.

South West is a similar dives site again of around 45 minutes away from Koh Tao, and having similar depts. These are two of the more popular dives sites around Koh Tao. Offering beautiful blue, warm clear water and a large variety of marine life to see. Of which giant groupers are some of the most impressive. Just because of their sheer size and presence.

The smaller variety of groupers such as Hexagon Groupers or the Blue Lined grouper can easily be seen at most of the shallower dive sites. Twins and White Rock are perfect for seeing these smaller groupers. Both sites are relatively close to the island, within a 20-minute journey time.

The dive sites are perfect for novice and the more experienced divers as they offer good conditions for diving, with good visibility and hardly any current, combined with a wide range of fish and corals to see twins and white rock are two of the most beautiful and more popular dive sites to visit while visiting Koh Tao.

To learn more about the different species of Grouper found in and around the waters of Koh tao ask your PADI Instructor about the PADI Fish Identification Specialty course.

Author: Andrew McEvoy (PADI MSDT #342956)

Crystal Dive Koh Tao

7/1 Moo 2
Tambon Ko Tao
Koh Tao
Surat Thani


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