species unique to Thailand include a rich assortment of cave-dwelling
forms such as Puntius
Cave Sheatfish (PlanetCatfish),
subterraneus (FishBase), Kittipong’s
Cave Loach (FishBase),
Schistura spiesi (Loaches
Online), and an endemic genus:
the Waterfall Climbing Cave Fish Cryptotora
Other endemic freshwater fish include
the Redtailed Black Shark (ARKive),
Somphong’s Rasbora (ARKive),
an armored stickleback Indostomus
a chameleonfish Badis
Ornate Sand Loach (Loaches
Online), and several catfishes: Kryptopterus vitreolus (Species New to Science),
Endemic marine fish include the Thai Damselfish (FishBase),
a goby Myersina adonis
and the grunts Plectorhinchus
Amphibians found only in Thailand include a bird-eating frog Limnonectes megastomias (Wildlife Extra), Smith's Wrinkled Frog (ARKive), the Inthanon Stream Toad (flickr), the Doi Chang Frog (flickr), Amolops panhai (flickr), the Phu Luang Cliff Frog (Species New to Science), Lekagul's Leaf Litter Frog (flickr), Fejervarya triora (siamensis.org), Rhacophorus jarujini (Zoological Soc. Japan pdf file), Leptolalax fuliginosus (p. 4 of Kyoto Univ. pdf file), and the Nakon Si Thammarat Caecilian Ichthyophis supachaii (Internet Archive).
Reptiles that occur nowhere else include Gumprecht's Green Pit Viper (Gernot Vogel), the Kanburi Pit Viper (Siam-Info), the Banded Green Cat Snake (Siam-Info), the Northern Keelback (flickr), Chanard's Mud Snake (Species New to Science), the Orange-tailed Ground Gecko (Gernot Vogel), the Siamese Green-eyed Gecko (Nature's Window), Chanhome’s Gecko (eol), a recently described false bloodsucker Pseudocalotes khaonanensis (Reptile Database), Gyldenstolpe’s Snake Skink (eol), and two endemic genera of skinks: Jarujinia (Species New to Science) and Miriam's Skink Davewakeum (Reptile Database)
Birds known solely from Thailand include the White-eyed River-martin (BirdLife Int'l) and Deignan’s Babbler (p. 26 of OBC pdf file), has sometimes been considered distinct from the more widespread Rufous-fronted Babbler Stachyris rufifrons and the Siamese Partridge Arborophila diversa (OBC) is sometimes treated as distinct from the Chestnut-headed Partridge Arborophila cambodiana.
Endemic mammals include Neill’s Rat Leopoldamys neilli (CERoPath), the Limestone Rat Niviventer hinpoon (CERoPath), a recently described horseshoe bat Rhinolophus thailandensis (Species New to Science), and perhaps the poorly known Williamson’s Mouse-deer (IUCN Red List). The extinct Schomburgk's Deer Rucervus schomburgki (Extinction Website) was known only from Thailand.
Beetles exclusive to Thailand include a jewel beetle Chrysochroa corbetti (Living Jewels), the stag beetles Hexarthrius nigritus (SIZ) and Lucanus koyamai (flickr), a flower beetle Platynocephalus miyashitai (SIZ), a dung beetle Enoplotrupes sharpi (Käfer der Welt), a rove beetle Schedolimulus komatsui (Zootaxa pdf file), and a longhorned beetle Anoplophora granata (Cerambycoidea.com). Other endemic insects include Aroon’s Silverline (SIZ), the Siamese Ringlet (SIZ), a hawk moth Leucophlebia frederkingi (Sphingidae of SE Asia), a katydid Lichnofugia rufa (SIZ), the Khao Soi Dao Shadow Damsel (ARKive), and another damselfly Coeliccia yamasakii (Asia Dragonfly).
Other endemic invertebrates include the Shocking Pink Dragon Millipede (Zootaxa pdf file), the Giant Mountain Crab Potamon bhumibol (p. 1 of ONEP pdf file), a tarantula Chilobrachys huahini (BioLib), a scorpion Heterometrus sejnai (p. 41 of Euscorpius 6 MB pdf file), and a mussel Modellnaia siamensis (ARKive). Endemic land snails include Alycaeus somnueki (jaxshells.org), Perrottetia dermapyrrhosa (Species ID), Arinia panhai (Femorale), Sarika diadema (p. 3 of Raffles Museum 3 MB pdf file), Anauchen smokon (p. 5 of ASEAN Biodiversity Info 5 MB pdf file), and Phuphania globosa (Species New to Science). Endemic marine molluscs include Attiliosa houarti (Eddie Hardy) and Orr’s Murex (BISHOGAI). A recently described sea slug Aiteng ater (IISE) is the sole member of a family known only from Pak Phanang Bay.
Vascular plant species restricted to Thailand include the orchids Paphiopedilum exul (rspg.org) and Pecteilis sagarikii (dnp.go.th), Magnolia sirindhorniae (ARKive), Mallotus glomerulatus (Flora of Thailand), Sapria ram (rspg.org), Rhododendron ludwigianum (rspg.org), Bauhinia siamensis (dnp.go.th), Delphinium siamense (rspg.org), Gardenia saxatilis (rspg.org), Selliguea hirsuta (Ferns of Thailand), Wrightia sirikitae (WNS Stamps), Dracaena jayniana (Kew), Cycas petrea (Cycad Pages), and Impatiens phuluangensis (dnp.go.th). Endemic genera include the White Elephant Palm (PACSOA), an orchid Lesliea (IOPSE), a bamboo Temochloa (p. 19 of chm-thai.onep.go.th pdf file), Santisukia (rspg.org), Somrania (Species New to Science), Khaosokia (NHM-London), Thepparatia (dnp.go.th), Marcania (dnp.go.th), Remirema (dnp.go.th), Tribounia (Species New to Science), and the gingers Cornukaempferia (Smithsonian) and Siamanthus (ARKive).
Portions of Thailand are included in two biodiversity hotspots: the Indo-Burma (CI) and the Sundaland (CI). The Chao Phraya (FEOW) is an important freshwater ecoregion and the Mekong River (WWF) has one of the world's richest freshwater faunas.