anuran

Anura is an order of amphibians that includes frogs and toads. It is the largest order within the class Amphibia, with about 7,000 described species. The name derives from the Greek an- meaning without and -oura meaning tail, reflecting the tailless adults of most species. Anurans are found on every continent except Antarctica and inhabit a wide range of environments, from forests and wetlands to deserts and high-altitude regions. Reproduction typically requires water or very moist habitats.

Anurans are characterized by their short bodies, broad heads, and well-developed hind limbs adapted for jumping. They lack tails in adulthood and possess a tympanic membrane, a pelvic girdle fused to the skull, and a three-chambered heart. They rely on lungs for part of their respiration, but many species also exchange gases through their moist skin. Most species lay eggs in water, and fertilization is usually external, often accompanied by amplexus, where the male grasps the female to fertilize eggs as they are released. Tadpoles hatch from eggs and are generally aquatic, feeding on algae and detritus, before undergoing metamorphosis into legged, tailed adults.

Ecology and conservation: anurans occupy diverse ecological roles as insectivores, prey for many predators, and indicators of environmental health due to their permeable skin and biphasic life cycle. They face threats from habitat destruction, pollution, climate change, invasive species, and diseases such as chytridiomycosis. Conservation efforts focus on habitat protection, pollution control, disease management, and monitoring population trends.