Tonga

Birds found nowhere else include the Polynesian Megapode or Malau (tongaturismo.info) and the Tongan Whistler (Theme Birds on Stamps).

Reptiles known solely from Tonga include the Eua Scaly-toed Gecko Lepidodactylus euaensis (Reptile Database) and the extinct Tongan Giant Skink Tachygia microlepis (Andrew Isles Bookshop), an endemic genus.

Marine fish unique to Tonga include the Blackfin Damselfish Amblyglyphidodon melanopterus (eol), the Swallowtail Fangblenny Meiacanthus procne (eol), the Tonga Fangblenny Meiacanthus tongaensis (eol), the Black Foxface Siganus niger (eol), the Tonga Grouper Epinephelus chlorocephalus (eol), the Tongan Spiny Basslet Acanthoplesiops naka (Zootaxa pdf file), a pufferfish Canthigaster flavoreticulata (UODAS), a goby Eviota tigrina (eol), and a combtooth blenny Praealticus multistriatus (Morphbank).

Insects restricted to Tonga include a leaf beetle Rhyparida punctatissima (Harvard), a longhorned beetle Mimoopsis insularis (Catalogue of Life), an ant Strumigenys zakharovi (p. 4 of Antbase pdf file), a planthopper Dystheatias periander (p. 11 of Bishop Museum pdf file), and a barklouse Lepidopsocus euaensis (p. 5 of Bishop Museum pdf file). Endemic jumping spiders include Chalcotropis insularis (Salticidae of the World) and Sobasina magna (Salticidae of the World). Endemic land snails include Vatusila tongensis (BHL), Graeffedon pricei (BHL), and Tuimalila pilsbryi and Tuimalila infundibulus (both at Internet Archive).

Marine invertebrates collected exclusively in Tongan waters include the molluscs Oliva hilli (Eddie Hardy), Calliotropis ptykte (Eddie Hardy), and Diodora tongana (Eddie Hardy).  Other invertebrates only known from Tonga include a squid Choneteuthis tongaensis (Wikipedia), a shrimp Periclimenes jackhintoni (AToL Decapoda pdf file), and a sea squirt Seriocarpa tongae (p. 8 of MNHN pdf file).

Vascular plant species occurring naturally only in Tonga include a fan palm Pritchardia pacifica (PACSOA) which has also been introduced to Fiji and elsewhere, a gymnosperm Podocarpus pallidus (IUCN Red List), Discocalyx listeri (Rare Plants of Tonga), Arytera bifoliata (Rare Plants of Tonga), Atractocarpus crosbyi (Rare Plants of Tonga), a tree fern Cyathea euaensis (NYBG), the trees Polyalthia amicorum (Rare Plants of Tonga) and Aglaia heterotricha (Rare Plants of Tonga), a recently discovered orchid Robiquetia tongaensis (p. 70 of Lankesteriana pdf file), Pittosporum yunckeri (Rare Plants of Tonga), Phyllanthus amicorum (Rare Plants of Tonga), Dysoxylum tongense (Rare Plants of Tonga), Casearia buelowii (Rare Plants of Tonga), Osteomeles anthyllidifolia (Rare Plants of Tonga), Ixora yunckeri (NYBG), Psychotria kaoensis (NYBG), and Solanum tongaense (NYBG).

Tonga is part of the Tongan Tropical Moist Forests terrestrial ecoregion (EoE) and the Polynesia - Micronesia biodiversity hotspot (Biodiversity Hotspots). For an overview of the natural history of Tonga see the National Biodiversity Strategy and Action Plan (CBD pdf file).