From the Blog

February 15, 2016

Aliens of Thailand

Boarder controls in the kingdom are fighting a losing battle as more and more aliens sneak into the country

 Invasive Alien Species Reinwardt flying frog


Did you know there are over 1,000 alien species of fish, reptiles, plants, and animals that now call Thailand home?

What are Invasive Alien Species?

Invasive alien species are plants, animals, pathogens and other organisms that are non-native to an ecosystem, and which may cause economic or environmental harm or adversely affect human health. In particular, they impact adversely upon biodiversity, including decline or elimination of native species – through competition, predation, or transmission of pathogens – and the disruption of local ecosystems and ecosystem functions.Invasive alien species, introduced and/or spread outside their natural habitats, have affected native biodiversity in almost every ecosystem type on earth and are one of the greatest threats to biodiversity. Since the 17th century, invasive alien species have contributed to nearly 40% of all animal extinctions for which the cause is known (CBD, 2006).

Thailand’s at times unwanted aliens also include many mammals we may not have considered as aliens, including rabbits, cats, goats, mice, rats and pigs, the feral populations of which wreak havoc on native Thai ecosystems.

That said a good number have brought with them multiple benefits from the ornamental gold fish who were first introduced around the 18th Century to many other exotic aquatic species of fish and shellfish that have followed. Many fish were intentionally introduced for varying purposes, including for food and for mosquito control.


Aliens of Thailand – The Good News

The main reason for introducing exotic species is for social and economic benefit, especially for aquaculture. Positive or beneficial aspects of exotic species include: FOOD SECURITY. Exotic species now contribute more than 63% of freshwater fish production in Thailand.


In 2001; fisheries statistics show that Thai people consume 28.8 kg of fish per capita, of which 41.6% was from exotic species. Nile tilapia (ปลานิล – Plā nil) and its strains make the highest contribution, followed by hybrid walking catfish (several million of which are released annually for merit making) and the common carp. Up to 1,000 exotic species have been imported for the Thai aquarium trade. Many species have been bred and improved into famous breeds for the global market, such as discuss, oscar, guppy and others.

Invasive Alien Species Nile tilapia

Public Health

Two ornamental fish species were introduced for mosquito control in Thailand; the guppy Poe cilia reticulate (also known as million fish and rainbow fish) and mosquito fish Gambusia affinis, both of which have a high tolerance to polluted water and come from South and Central America respectively, while others are utilized for algae control in brackish water shrimp ponds.


The Not So Good News

It’s not all good news as some exotic species have become invasive alien species (IAS) to Thailand, with several carnivorous fish and amphibians causing population decline in indigenous species, it would also appear most alien species can adapt quicker and have a higher tolerance to habitat change, which makes them better at competing with native species, in both foraging and securing spawning grounds. It is also reported certain species carry disease which can wreak havoc on their indigenous cousins.

This alien invasion is not just about marine life, among the world’s 205 invasive plants 71 exist in Thailand. They include 15 aquatic plants, 10 grasses, 6 herbs, 2 palms, 23 shrubs/trees, 13 vine/climbers and 2 shrubs/climbers.

Invasive Alien Species Thai Name Talapad Ruesi, Bon Chin

Thai Name Talapad Ruesi, Bon Chin used as a vegetable, medicinal and more


The Not so Pleasant Alien Creatures

The biggest of the alien Fauna roaming the Kingdom are the Caiman Crocodile, (males generally reach 2.0 m to 2.5 m) whose normal habitat is in South America, they are not the only large amphibians to take up residency here in Thailand we are now home to the larger, mainly nocturnal New Guinea Crocodile, which is native to Papua New Guinea and where the male can grow up to a length of 3.5 m.

Invasive Alien Species New Guinea Crocodile


Copy right       

This site may contain copyrighted material, the use of which has not always been authorized by the copyright owner. Such material, is made available in an effort to advance understanding of Thailand, or topic discussed in the article. This constitutes ‘fair use’, of any such copyrighted material as provided for, in section 107 of the US Copyright Law.

In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit. If you wish to use copyrighted material from this site, for purposes of your own that go beyond ‘fair use,’ you must obtain permission from the copyright owner.

If you are the copyright owner and would like this content removed from, please contact us.



Have your say

Another Great Website by SEO Siam - © 2013 Asia Backpackers | Sophocles Theme Details