Classification: Introduced Species

Rhinella horribilis is the scientific name used for populations of the cane toad or giant toad located in Mesoamerica and north-western South America when they are considered to be a separate species from Rhinella marina, a name which is then mostly restricted to Amazon basin populations. R. horribilis was originally described from Mexico as Bufo horribilis before later being considered a synonym of Bufo marina and later Rhinella marina. The specific epithet horribilis has now been revived after a 2016 study argued that these populations in fact make up two separate populations.

Description:

Rhinella horribilis is a large, warty, brown or dark-mottled terrestrial toad (bufonid) that can weigh up to 3.3 lbs. External morphology is indistinguishable from R. marina, requiring radiographical examination of skull morphology or genetic testing to differentiate them.

Like R. marina, these toads have a pair of large parotoid glands that produce bufotoxins, which act as neurotoxins, each extending from just behind the eye, far down the side of the body. The pupils of the eye are horizontal and the irises golden, with distinct ridges running from above their eyes down the snout. The tadpoles are black dorsally, with a belly that is silvery white with black spots. Adult males can be identified by their more robust forelimbs for amplexus than adult females.

Unlike native Southern Toads (Anaxyrus terrestris) and American Toads (A. americanus) which have relatively small, oval paratoid glands, the paratoid glands of Cane Toads (Rhinella spp.) are large and triangular paratoid glands. Cane toads also have ridges or crests on top of the head between the eyes. Size: 2 - 9.3 inches SVL (snout-vent length; measurement from snout to base of tailbone). Individuals found in the U.S. rarely exceed 7 inches SVL.

Habitat: Inhabits open grassland and woodland, and has displayed a "distinct preference" for areas modified by humans, such as gardens and drainage ditches. In their native habitats, the toads can be found in subtropical forests, although dense foliage tends to limit their dispersal.

Range: Rhinella horribilis are indigenous from South American west of the Andes to extreme southern Texas.

Found in these States: TX

Diet: Most frogs identify prey by movement, and vision appears to be the primary method by which the cane toad detects prey; however, it can also locate food using its sense of smell. They eat a wide range of material; in addition to the normal prey of small rodents, other small mammals, reptiles, other amphibians, birds, and even bats and a range of invertebrates (such as ants, beetles, earwigs, dragonflies, grasshoppers, true bugs, crustaceans, and gastropods), they also eat plants, dog food, cat food, feces, and household refuse.

Reproduction: The giant toad, as does the cane toad, begins life as an egg, which is laid as part of long strings of jelly in water. A female lays 8,000 to 25,000 eggs at once and the strings can stretch up to 66 ft in length. The black eggs are covered by a membrane and their diameter is about 0.067 to 0.079 inches. The rate at which an egg grows into a tadpole increases with temperature. Tadpoles typically hatch within 48 hours, but the period can vary from 14 hours to almost a week. This process usually involves thousands of tadpoles which are small, black, and have short tails forming into groups. Between 12 and 60 days are needed for the tadpoles to develop into juveniles, with four weeks being typical. Similarly to their adult counterparts, eggs and tadpoles are toxic to many animals.

Status: Globally it is a species of least concern. Here in the United States it is apparently secure.

Taxonomy: