The Marine Toad

 Amphibians, Australia, Invasive Species, South America  Comments Off on The Marine Toad
Jan 012010
photo by Sam Fraser-Smith on Flickr Creative CommonsHomeCentral and South America, and introduced worldwide
Habitatnearly every temperate habitat, from rainforest to savannah, farmland to suburbia
Nichelarge opportunistic predator
Favorite Foodinsects
Lengthup to 9 inches
Invasive Species

The marine toad is the largest toad on Earth by far, growing as big as 9 inches in length. They are insatiable hunters, prowling their territories by night and gobbling up anything that can fit in their mouths. In addition to their staple diet of insects, they will scarf down unlucky salamanders and even small frogs. As if their massive size wasn’t enough to deter predators, marine toads also sport a deadly defense mechanism. If an animal picks up the toad in its jaws, special glands in the amphibian’s skin will ooze a highly toxic venom. The hapless predator scarcely has time to wish it never chose the toad as its last meal, as most are killed within 15 minutes of ingesting the poison.

In many regions of the world, especially Australia, the marine toad is an invasive species, competing with native frogs and toads for food and water. In certain cases, the introduction of marine toads was deliberate, particularly in countries that grow sugar cane. Since these toads are so voracious and are useful in pest control, they were thought to be effective watchdogs of sugar cane crops and earned the name cane toad. Although some farmers may have benefited from the introduction of cane toads, local ecosystems have been devastated. Marine toads are tough amphibians that can thrive in just about any environment on earth. Unlike frogs, they have thick, warty skin that allows them freedom from standing water except for mating. They are also tolerant to salt water, which amphibians usually shun, and can go without water entirely for long stretches of time. They are the ultimate survivors of the amphibian family, for better or for worse.

Because of their wide distribution, high tolerance, and high reproductive rate (over 20,000 eggs are laid in a clutch), marine toads are common and unlikely to be impacted by many of the same forces jeopardizing the survival of their frog and toad cousins. The marine toad is an example of how a hardy survivor can carve out its own niches in new areas, to the detriment of other species.