A tadpole with rear legs sits in shallow water near rocks.
Amphibians are a diverse group of animals that often undergo striking physical changes during their life cycles. The tadpole pictured above has sprouted tiny rear legs that will replace its muscular tail. Amphibians are specially adapted to certain environments and adapt further by region and habitat.

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Amphibians are a unique group of animals that begin life in water, and in many cases undergo major changes to survive on land. Toads, frogs, and salamanders typically start off as a gelatinous egg, which hatches into a larva that uses gills to breath water and a tail to swim. Over time, the larvae experience major changes in a process known as "metamorphosis". During this time, they will develop lungs to breath air and legs for walking and hopping. Their nervous system and cognitive abilities are refined, and they lose their tail and gills. Within weeks, they leave the water and will survive on land. The generally dry nature of the Sonoran Desert limits the diversity of amphibians, but those that call this area home are well adapted and can be observed with a little searching.

Though some amphibians are an expected group of animals at Organ Pipe Cactus, fish is likely not something you'd expect to find in the desert. Though the Quitobaquito pupfish is only found in this national monument, other species of pupfish are found in other unexpected places like Death Valley and White Sands National Parks. Pupfish are small, often seasonally colorful fish that inhabit harsh environments. Learn about toad monitoring research happening at Organ Pipe Cactus.

An olive-green toad with a prominent amber eye, crouched on gravel.

NPS photo

Sonoran Desert Toad (Incilius alvarius)

The Sonoran Desert toad, known also as the Colorado River toad is a well-known amphibian of the southwest United States, and the largest native toad in the U.S. This toad takes refuge in burrows and cool caves to escape intense daytime heat, coming out at night to forage for invertebrates, lizards, and even small mammals. Sonoran Desert toads secrete potent toxins from structures called parotoid glands located behind their eyes. These toxins are deadly to pets and harmful to humans.

Identify this Toad

Sonoran Desert toads are chunky bodied amphibians covered in small lumpy glands. They are typically a muddy green-gray color with some cream coloring around the mouth and belly, with a prominent white wart near the mouth. The bright amber eye is in front of the large oval parotoid gland and the circular eardrum, or tympanum. An adult toad is about the size of a hefty hamburger. The call is a short, low pitched “toot”. This toad’s eggs are laid in long chains in water.

A toad next to a cactus pad. The toad is brownish with red and gray spots.

NPS photo

Red-spotted Toad (Anaxyrus punctatus)

The red-spotted toad is a small (about the size of a small apple) amphibian found around the southwest United States. These toads live and forage near washes, hiding in the daytime, and searching for small invertebrates at night. Red-spotted toads become very active after rain, and many will emerge at once.

Identify this Toad

The red-spotted toad is predominantly an olive gray, brown, or dusty red color with a lighter underbelly. The green upper body is dotted with red spots, as well as gray to black spots. The parotoid glands behind the dark eyes are small and round. This toad has a musical trill that may be confused with insect noises. Red-spotted toad eggs are laid individually, instead of in clumps or chains.

A male pupfish with light blue scales stands out against brown sand.

NPS photo

Quitobaquito Pupfish (Cyprinodon eremus)

The Quitobaquito or Sonoyta pupfish is a distinct fish species that was isolated in small pockets as regional rivers changed course. This fish is named for it’s “playful” behavior, chasing and circling each other; this behavior is actually the aggressive behavior by the males during mating season.

Identify this Fish

The Quitobaquito pupfish is small, roughly the size of the bottom section of your index finger, and cigar shaped. The face is blunt, and the fins are small and rounded. Both sexes are typically dull brown in color and mottled, providing camouflage in their shallow water environments. During the breeding season in the late spring, males turn a striking blue, and aggressively patrol their territories and defend mates. The only natural occurrence of this fish is at Quitobaquito Spring at the southern end of the monument. The visitor center maintains a small pupfish population in a pond that you may visit.


Amphibians of Arizona

Last updated: October 4, 2023

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10 Organ Pipe Drive
Ajo, AZ 85321



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