Amfibienii

Amfibienii are a class of cold-blooded vertebrate animals that typically spend part of their lives in water and part on land. The name "amphibian" comes from the Greek words "amphi" meaning both and "bios" meaning life, reflecting their dual existence. This class includes familiar creatures such as frogs, toads, salamanders, and newts.

A defining characteristic of most amphibians is their metamorphosis. They usually hatch from eggs laid in water as larvae, which breathe with gills and are fully aquatic. As they mature, they undergo a remarkable transformation, developing lungs for breathing air and limbs for movement on land, though many retain a strong dependence on moist environments. Their skin is smooth, moist, and permeable, playing a crucial role in respiration and absorbing water.

Amphibians are found on every continent except Antarctica. They inhabit a wide range of environments, from tropical rainforests and temperate woodlands to ponds, streams, and even deserts, though they require access to water or extremely humid conditions to prevent their delicate skin from drying out. Their diet primarily consists of insects, worms, and other small invertebrates, making them important regulators of invertebrate populations. Due to their permeable skin, amphibians are particularly sensitive to environmental changes and pollution, serving as key indicator species for ecosystem health.