There are at least 1200 species of venomous creatures in the oceans around the world, and while we are incredibly fortunate here on Koh Tao that we are not home to many, we do have some inhabitants that can pack a punch if not treated with the respect they deserve! Read on to find out more, but do bear in mind that all of the marine life we will discuss here are very passive, and will not cause you any harm if you interact sensibly with them, and abide by the most important golden rule of diving – look but don’t touch!
The Scorpion Fish (Family Scorpaenidae)
This family includes not just Scorpion Fish, but also Stone Fish, the Indian Walkman and the Lion fish. All of these fish are masters of camouflage, and have spines that can inject toxins into any predators that get too close. Whilst Stone Fish are not native to Koh Tao, those with a keen eye may find Scorpion Fish at most dive sites. Lion Fish are seldom seen here, but there are a few – especially when exploring out in the sand at Pottery or in the channel at Japanese Gardens. And whilst difficult to spot, Indian Ocean Walkman’s are most often found on night dives, most commonly at White Rock.
The Puffer fishes (Family Tetraodontidae)
These funny looking fish has a highly elastic stomach and has the ability to take in huge amounts of water or air if necessary, to blow itself up into a huge ball several times their size, protecting itself against predators. However, if a predator manages to grab a puffer before it inflates it will come off rather badly. Most puffer fish contains tetrodotoxin, a substance 1,200 times more toxic than cyanide, that makes them taste foul and often is lethal to other fish.
The Banded Sea Snake (Laticauda Colubrine)
These can grow up to 128cm long with anything from 20-65 bands. The sea snake is quite a docile creature and not at all aggressive unless provoked.
The Crown of Thorns (Acanthaster Planci)
This majestic looking and unusually large starfish which can grow up to 1m in diameter. It has up to 21 arms, with the entire upper surface of its body covered in long venomous spines that can break off and become embedded any predator that gets too close. They are voracious predators that release the contents of their stomach on to the coral. Digestive juices then liquefy the coral ready for consumption. A single individual can wipe out large areas in this way and has scientists concerned as it is playing a major role in the destruction of the coral reefs in Australia.
We do get a variety of jellyfish here on Koh Tao, although the most common time to see one is when you’re sitting at your safety stop depth above one of the dive sites. Jellyfish have no method of propulsion of their own for direction, so are ultimately at the mercy of the ocean currents and waves for where they end up. All jellyfish have stinging tentacles, for which the treatment for contact is vinegar (or pee!) over them as soon as possible. This prevents any un-discharged stinging cells on the tentacles from firing even more venom.
For more information about the species commonly found around Koh Tao, feel free to check out our marine life page. You could also ask one of our dive leaders, all of whom are full on fun fishy facts about creatures found in our tropical waters! And whilst diving always remember the golden rule…..look don’t touch!