Ranids

Ranids are members of the family Ranidae, widely regarded as the true frogs within the order Anura of the class Amphibia. The family contains roughly 400 species distributed throughout the world, excluding Antarctica. Ranids typically inhabit a range of moist environments, from aquatic streams and ponds to damp terrestrial habitats such as forests and grasslands. Many species occupy both wet and dry periods of the year, showing a high degree of ecological flexibility.

Morphologically, ranids generally possess smooth, often gray or green skin, long hind limbs adapted for leaping, and webbed feet in many aquatic species. Their throats contain a vocal sac used in mating calls, and most have large, protruding eyes well suited for detecting predators and prey. Ranids are characterized by the absence of a tongue, which they employ to capture prey by suction.

The family is subdivided into several subfamilies and genera, with the genus Rana—encompassing species such as the common frog (Rana temporaria) and the bullfrog (Lithobates catesbeianus, formerly Rana catesbeiana)—being one of the most well‑known. Taxonomic relationships within Ranidae remain a subject of active research, as DNA sequencing has prompted re‑evaluations of traditional groupings.

Ranids play a crucial role in ecosystems as both predators of insects and as prey for birds, mammals, and other amphibians. Their permeable skin makes them sensitive indicators of environmental health, rendering them useful in monitoring pollution and climate change effects. Conservation concerns for ranids include habitat destruction, water pollution, the spread of diseases such as chytridiomycosis, and introduced predators. Several ranid species are currently listed as threatened or endangered, highlighting the importance of habitat protection and disease management for maintaining global amphibian diversity.