Home: Animals: Amphibians: Marine Toad

Bio Facts: Marine Toad
Common Name: Marine Toad or Giant Toad Marine Toad
Scientific Name: Bufo marinus
Family: Bufonidae
Order: Anuran
Class: Amphibia
Range: Patagonia to southern Texas. Introduced in Florida, Puerto Rico, Haiti, Hawaii, and Australia.
Habitat: Generally found in temperate to sub-tropical forests near a water source (where breeding takes place).
Description: This extremely large toad reaches a size of up to 9 inches long.  Females are generally larger than males.  Skin is usually brown or grayish brown above with occasional cream spots scattered over the back, sides, and legs.  The underside is creamy yellow, sometimes flecked with black.  The back and legs are covered with spiny warts.  There are large parotid glands behind the eyes and over the shoulders.
Life Expectancy: Known to live up to 40 years in captivity.  Life span in the wild is generally much shorter due to heavy predation in native habitats.
Sexual Maturity:

Probably at 18 months or less
Diet: In the wild, they eat insects, fish, and other small animals.  In the Zoo, they are fed crickets and super mealworms.
Status: Not listed
Behaviors:

Marine toads are nocturnal, active at night, sleeping and concealing themselves by day. They emerge from hiding at night and feed on any small animal that 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.

Marine toads will eat virtually anything they can catch and fit in their mouths. They have large appetites and are usually voracious feeders, using persistence, energy, and incredible speed to capture their prey.

Eggs are laid from late spring to summer in temporary pools and roadside ditches.  Eggs are laid in two strings that lay on the surface or are wrapped around objects in the water.  Eggs will hatch in about three days.  The tadpoles are jet black above and silvery white with black spots below.  They metamorphose in 45-50 days.
Adaptations:

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 to secrete a milky fluid from these warts.  It acts 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 pumping of air backward and forward over the vocal cords produces the mating call. When a toad swallows, a peculiar process occurs.  The eyes close and sink into the roof of the mouth. This action propels food into the gullet.

Special Interest:

Marine toads produce powerful toxins concentrated in their parotid glands. When under extreme stress (such as a predator attack) marine toads can release enough toxin (a milky white sticky fluid) to quickly kill a large dog.

The marine toad, a native of South America, was introduced into Dade County in 1955 to help control a specific beetle that destroys sugar cane.  Some accidentally escaped from the Miami Airport, too.

These large toads are commonly seen around streetlights in the suburbs and have adapted well to suburban life.  In fact, not only do they eat insects, they will consume cat or dog food. 

If a cat or dog bites the toad, it may become ill from the milky bufotosin that is released from the parotid glands.
Folklore:

Toads were sometimes considered to be positive omens, that good fortune was expected within the very near future. Perhaps this is because toads are likely to be near fresh water.  Throughout history fresh water was a precious commodity, so the appearance of a toad was good luck. Therefore to kill a toad was thought to not only affect the water supply, but also the rainfall. Some believed that this would mean there would be less rain, while in some countries it was thought that this action would lead to flooding.

In Mexico, the toad represented the earth.  And in some rural areas, it was thought that if newlyweds saw a toad in the road, they would have a happy marriage.
Conservation: Conservation measures worldwide for amphibians need to be supported if we want to be able to continue to enjoy these fascinating creatures.  Throughout the marine toad’s historic range, the rapid decline of suitable habitat due to human encroachment, development and pollution is causing a decline in their wild numbers. In introduced regions the marine toad tends to be prolific and stable.  Today, the marine toad is common throughout Dade County, Broward County, and the Everglades.
Jacksonville Zoo History: A recent acquisition, this species first appears in the Zoo’s animal collection in November 2000 as part of the Wild Florida attraction.
Revised July 2001