Toads are terrestrial amphibians belonging primarily to the family Bufonidae (true toads). Though often confused with frogs, toads possess distinct physical traits that allow for visual identification. This guide focuses on the anatomical features that define a toad and distinguish them from other amphibians.
Defining Characteristics: Skin and Body Structure
The most immediate visual cue for a toad is its skin, which appears dry, rough, and noticeably bumpy, giving it a warty texture. These bumps are specialized granular glands that help the amphibian retain moisture, allowing it to spend extended periods away from water sources.
The toad’s overall body is characterized by a stout, wide, and squat appearance, lacking the sleek, streamlined build of many frogs. Their head connects directly to the body without a distinct neck, contributing to their compact profile.
In contrast to the long, powerful hind legs of leaping amphibians, toads possess short, stubby back legs. These limbs are better adapted for walking, crawling, or executing short, shuffling hops rather than the long, graceful jumps seen in frogs.
Unique Identification Markers
Specific structures on a toad’s head act as reliable identification markers, starting with the prominent parotoid glands. These are large, raised lumps situated conspicuously behind each eye, often extending toward the shoulders. The parotoid glands produce and secrete bufotoxin, a milky, noxious substance that serves as a chemical defense against predators.
Many true toad species also exhibit cranial crests, which are bony ridges found either above the eyes or running between them. While the size and shape of these crests vary, their presence is a characteristic feature of the Bufonidae family.
A close look at the eyes reveals another distinguishing trait: the pupils are typically horizontal slit-shaped, contrasting with the round pupils common in many other amphibians. The eyes themselves are often bulbous and protrude noticeably from the head.
How Toads Differ from Frogs
The visual distinction between a toad and a frog involves key differences in anatomy and movement. Toads move by walking or making small hops, reflecting their tolerance for drier, terrestrial habitats. Frogs, conversely, execute long, powerful leaps.
The skin textures are a clear contrast: toads display dry, rough, warty skin, while most frogs possess smooth, moist skin. The frog’s moist skin allows for greater water and oxygen absorption, tying them closely to aquatic environments.
True toads lack teeth entirely, relying on strong jaws to swallow prey whole. Most frogs, however, possess small vomerine teeth on their upper jaw to help secure struggling prey. The toad maintains a stout and broad body profile, while the typical frog has a more slender body built for agility.