How many fish in the sea?

One of the greatest things about diving around Koh Tao is all the amazing, colorful, and unique fish life. Often when diving here you just keep seeing one new species after another, to the point where you start to wonder, just how many species are there around this island? Well a new paper we have co-authored sets about to get us a little bit closer to answering that question.


The paper, titled “An update to the list of coral reef fishes from Koh Tao, Gulf of Thailand” was published in Checklist: The Journal of Biodiversity Data. It lists 21 new species records for the island, 7 of which are new for the Gulf of Thailand. That brings the total number of recorded fish species for Koh Tao to 223, belonging to 53 different families. But of course we all know there are way more out there we have yet to record or even see.


The Reef Stonefish, (Synanceia verrucosa). One of the new records for the Gulf of Thailand.

The Reef Stonefish, (Synanceia verrucosa). One of the new records for the Gulf of Thailand.


Studies on the biodiversity and geographic range of species are incredibly important in today’s world of climate change and unprecedented levels of habitat destruction. According to a report published in Nature in 2004, species are currently being lost at a rate of 1,000-50,000 per year, putting between 30-50% of all species at risk of extinction by mid-century. It is not known with any accuracy how many species are being lost, because most species on the planet are yet to be even discovered. As of 2009, 1.2 million species of plants and animals had been described, but it is estimated that the total on the planet is about 8.7 million (Chapman 2009).


In the ocean, about 91% of the marine species are yet to be described, with only 171,082 of the 2.1 million species being known to science (Mora 2011). That leaves a lot of work yet to be completed, and with species being lost so quickly it makes you wonder just how many will never been known or studied at all. Douglas Adams may have said it best when he wrote:


“Scrabbling to record the mere existence of species before they become extinct – it is like someone hurrying through a burning library desperately trying to jolt down some of the titles of books that will now never be read”

[From, Last Chance to See]


Our new study hopefully helps at least a little bit in achieving that global goal, but for our island can help us better pinpoint any changes in the population dynamics and biodiversity of reefs to better inform the local mangers and policy makers.


The Marbled Snake Eel

The Marbled Snake Eel

Below you can find the list of the 7 new species described for the Gulf of Thailand


  1.  Spotfin Frogfish, Antennatus nummifer (Antennariidae),
  2. The Yellow Margin Triggerfish, Pseudobalistes flavimarginatus (Balistidae),
  3. The Fanbelly Leatherjackect, Monacanthus chinensis (Monacanthidae),
  4. The Marbled Snake eel Callechelys marmorata (Ophichthyidae),
  5. The Longsnout Flathead, Thysnophrys cf. chiltonae (Platycephalidae),
  6. The Green Humphead parrotfish, Bolbometopon muricatum (Scaridae)
  7. The Reef Stonefish, Synanceia cf. verrucosa (Synanceidae)


You can download the full paper by Dr. Patrick Scaps and Chad Scott in PDF form here. It also contains an updated list of all 223 fish species currently recorded for Koh Tao.