Giant Marine Toad

Giant Marine Toad


Pantagonia to southern Texas. Introduced by man for pest control in Puerto Rico, Haiti, Hawaii, and Australia


They prefer open, damp, leaf-littered fields where insect food is plentiful


The giant toad is one of the largest species of toad, reaching a length of 9 inches. The female is usually larger than the male. They have a short, squat body and short legs. Toads usually crawl or progress in short hopping movements. Their skin is dry and covered with tubercles or warts. These warts are collections of poison glands. When a toad is attacked, its defense is exuding a milky fluid from these warts which act as an irritant to the mucous membranes of the attacker. The poison does not protect the toad against all predators, for most snakes and birds seem to be unaffected. There are 2 concentrations of the poisonous glands behind each eye. They are known as parotid glands. Toads have a tympanic membrane on either side of their head right behind the eye. It is correlated with the ability of toads to produce sounds. The mating call is produced by the pumping of air backward and forward over the vocal cords. When a toad swallows, a peculiar process, involving the closing of the eyes and the sinking of the eyeballs into the roof of the mouth, takes place. This action aids to propel the food into the gullet.


Toads are nocturnal. They emerge from hiding at night and feed on any small animal which moves. Toads have a marked homing instinct in which the mechanism is not fully understood. Even when not breeding, toads display a high degree of constancy in returning to a favorite retreat every day.


Usually in March, the toads migrate to the breeding pond where the males attract the females by their calling. They usually call while raising themselves on their front legs in shallow water. The male clasps the female behind the arms and the pair swim about in amplexus until the female comes into contact with some water weed. The female extrudes the eggs in the form of a long string while the male ejects sperm over them. This continues at intervals for several hours. The female swims around so that the long string of eggs, about 7-10 feet long, is wrapped around the water weed. The tadpoles hatch after 12 days. The female can lay 35,000 eggs. The time taken to develop into an adult varies, depending on the temperature. About 3 months is an average period.

Interesting Facts:

Though considered harmless and in some places even beneficial to man because of the enormous numbers of insects which they eat, in Australia they are considered a huge pest. These toads, also called cane toads, were orignially introduced in 1935 to Queensland, Astralia in an attempt to control beetle pests of sugar cane. However, since its introduction, the cane toad has proved to be a highly invasive pest and is still spreading across northern and eastern Australia. The species is posionous in all its life stages: eggs, tadpoles, juveniles and adults. A number of native Australian species are now under threat because of lethal ingestion of cane toad toxin.

About Our Animals:

This animal is used in the Zoo\\\\\\\'s Education Programs and is not on display to the public, but is taken out to schools and community centers as part of the Zoo\\\\\\\'s Outreach Program.

Giant Marine Toad
Class: amphibians
Genus: Bufo
Species: marinus
Length: Up to 9 inches
Average Lifespan: 6
Wild Diet: Worms and many types of insects
Predators: Only a minute fraction of the baby toads survive to grow up because of their many predators. Dragonfly larvae and other preying water insects kill the toad larvae. When the toads are mature, dogs, snakes, larger frogs and toads, and birds, all prey on them.
USFWS Status: Not Listed
CITES Status: Not Listed
Where at the Zoo? Off Exhibit: Education Animal Facility

Learn more about amphibians or animals from South America!
Or, cross-reference the two!