Gastrophryne carolinensisEastern Narrow-mouthed Toad

Geographic Range

The Eastern Narrowmouth Toad or Gastrophryne carolinensis can be found throughout the entire southeastern portion of North America and the Florida Keys. Their range extends into eastern Texas and Oklahoma. They have also been introduced to the Bahamas (Conant and Collins, 1998).


Gastrophryne carolinensis has a wide variety of habitats with only two requirements. These are shelter and moisture. Narrowmouth toads are very good burrowers, and therefore may be abundant in an area without leaving any visable signs. These toads can be found by over turning boards, logs, or other shelters. Also, they can be found in vegetable debris or sawdust piles (Conant and Collins, 1998). Another place that narrowmouth toads can be found is just under the surface of suburban lawns that are abundant in sand and are watered often (Bartlett, 1999).

Physical Description

One distinguishing characteristic of G. carolinensis is the fold of skin that runs across the head directly behind their eyes. This flap of skin can fold forward to remove insects that are attacking the eyes. Color varies depending on the habitat. They can range from light tan to brown, red, and even nearly black. They have a broad dark middorsal area with light strips that are commonly covered by patches, spots, and mottlings of dark or light pigment. The stomach is strongly mottled. They also lack a tympanum. The body of G. carolinensis is round with a narrow head that is sharp and pointed, and has a small mouth. There is sexual dimorphism in color. Males have a darkly pigmented throat whereas females do not. (Conant and Collins, 1998)

Tadpoles of G. carolinensis are black and have flecks of dark blue. They also may have a tan lateral line. The tailfins have dark specks on them, as well as dark tips (Bartlett, 1999).



Breeding sites are usually in shallow water, but deep water is also used if covered by a mat of floating vegetation. These breeding sites can be anything from shallow ditches, to semipermanent ponds and irrigated agricultural areas. Rains initiate their breeding season, which may occur between early April and October in the south or midsummer in areas farther to the north. Most often the narrowmouth toad will call from the grasses surrounding the breeding pool. The male also will sometimes call the female while floating in the water, although it is more rare.

Eggs are deposited in small floating clusters, and up to 800 eggs have been reported coming from a single female (Bartlett, 1999).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    547 days
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    365 days



Gastrophryne carolinensis is primarily nocturnal. Its primary breeding season is between March and September, depending on the rain. During the breeding season is the best time to hear the vocalization of G. carolinensis. The call of the male has best been described as a penetrating, nasal, sheep-like bleat (Bartlett, 1999). There is no trill-like sound like many other frogs and toads.

Food Habits

The diet of the Eastern Narrowmouth Toad consists mostly of insects like beetles, termites, and especially ants. This toad has been found feeding right at the openings to anthills.

Conservation Status

Other Comments

The skin of G. carolinensis is smooth which is not a common characteristic amongst other varieties of toads. Most toads have rough skin that is usually lumpy in appearance and skin texture.


Darren Kalis (author), Michigan State University, James Harding (editor), Michigan State University.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


Bartlett, R. 1999. A Field Guide to Texas Reptiles ans Amphibians. Houston, Texas: Gulf Publishing Company.

Conant, R., J. Collins. 1998. A Field Guide To Reptiles and Amphibians. Boston, New York: Houghton Mifflin Company.

Northern Prairie Wildlife Research Center, .. 1999. "Eastern Narrowmouth Toad" (On-line). Accessed December 10, 1999 at