Horse
Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus".
Fauna of Puerto Rico
All species of Ranidae and Hylidae occurring in Puerto Rico are introduced. One species from the family Bufonidae, the cane toad, is introduced while the other, the Puerto Rican crested toad, is endemic and critically endangered. The cane toad was introduced to Puerto Rico in the 1920s to control the populations of white-grub ("Phyllophaga" spp.), a sugar cane pest. All species from the family Leptodactylidae are native to the region. Of the 18 Leptodactylidae species, 17 are from the genus "Eleutherodactylus" and are commonly known in Puerto Rico as coquís. Three of these, the web-footed coquí, the golden coqui and the mottled coqui, are likely to be extinct. The golden coqui is the only live-bearing species from the family Leptodactylidae and Cook's robber frog ("E. cooki") is the only "Eleutherodactylus" sp. that exhibits sexual dimorphism in both size and color. The common coquí ("Eleutherodactylus coqui") is an unofficial national symbol of Puerto Rico and an important aspect of Puerto Rican culture. Since 14 of the 17 coquís are endemic to the archipelago, a common phrase used by Puerto Ricans to assert their national pride is ""De aquí como el coquí"" (From here Puerto Rico like the coquí).
Puerto Rico's turtle fauna includes both freshwater (5 species, including two extinct species) and marine turtles (5). Two of these species, the hawksbill turtle and the leatherback sea turtle, are critically endangered. Threats to these species include habitat destruction and illegal capture of eggs and individuals. The spectacled caiman, an introduced species, is the only representative of the order Crocodilia in Puerto Rico.
The 11 snake species occurring in Puerto Rico are generally considered non-venomous, although research has concluded that at least one species, the Puerto Rican racer ("Alsophis portoricensis"), secretes venom. These species belong to 3 families and 4 genera: Typhlopidae (genus "Typhlops"), Boidae ("Epicrates") and Colubridae ("Alsophis" and "Arrhyton"). The largest snake in Puerto Rico is the endemic Puerto Rican boa ("Epicrates inornatus") with a maximum length of 12 ft (3.7 m). The diet of snakes in Puerto Rico consists of reptiles ("Ameiva", "Anolis", geckos), "coquís" and other frogs, and, to a lesser extent, mice, birds and bats (exclusively by the Puerto Rican Boa).