Toads ARE amphibians.
Toads are amphibians, closely related to frogs, consisting of approximately five hundred thirty species among thirty seven genera within the taxonomic order Anura. Unlike frogs, however, which commonly live in wetter habitats and possess a smooth, moist, slippery skin, toads can often also inhabit more arid environments and are generally characterized by bumpy, leathery skin often said to resemble “warts”. As amphibians, the life cycle and biology of both toads and frogs are inextricably linked to the water, where they lay their eggs and live as larvae before undergoing their metamorphosis into full grown adults.
Amphibian Physical Traits
The general biological traits of amphibians, such as toads and frogs, include being tetrapod vertebrates, adapted to both terrestrial and fresh water aquatic environments, with the ability to use their skin for respiration. This ability to use their skin for respiration in conjunction with, or in lieu of, gills or lungs is considered a biological adaptation unique to amphibians. Toads are also cold blooded amphibians, which means they are not able to produce their own internal body heat and must instead rely on the conditions of their external environment for warmth. Furthermore, many toads possess specialized poison glands on their heads or in their skin, which secrete a toxic or foul tasting substance to deter predators.
The Amphibian Life Cycle
As amphibians, toads and frogs undergo a special life cycle, which involves distinct life phases spent in both fresh water aquatic and terrestrial habitats. The vast majority of toads begin their amphibious lives as tiny eggs deposited by a female toad in a body of fresh water, where they eventually grow and develop into larvae commonly known as tadpoles. These immature tadpoles live in the water feeding on microorganisms, moving about with a small tail, and using gills to breathe. At this aquatic stage in their amphibian life cycle, the toad tadpoles are more similar to immature fish in most biological respects including anatomy, physiology, and behavior. As the toad tadpoles continue to develop, they become less like fish and more like land based creatures, such as reptiles. These changes include losing their tadpole tails, developing primitive lungs, an enlargement of their overall bodies, and the development of a more advanced circulatory system suitable for terrestrial environments. This profound metamorphosis in toads and frogs from aquatic an organism to a terrestrial organism is typically considered one of the primary characteristics of amphibians, which sets them apart from other similar creatures.
American Museum of Natural History.
Amphibian Species of the World 5.6 – Bufonidae.