pouíssons

Pouissons, a term derived from the French word for fish, can refer to a broad category of aquatic life. In scientific classification, "fish" encompasses a vast and diverse group of gill-bearing aquatic animals that lack limbs with digits. This definition typically includes jawless fish (agnathans), cartilaginous fish (chondrichthyes), and bony fish (osteichthyes). These creatures inhabit virtually every aquatic environment on Earth, from the shallowest tide pools to the deepest ocean trenches, and from freshwater lakes and rivers to brackish estuaries.

The evolutionary history of pouissons spans hundreds of millions of years, with the earliest known vertebrates being fish-like organisms. Their physical characteristics are incredibly varied, reflecting adaptation to a wide array of ecological niches. Features such as fins, scales, and specialized respiratory systems (gills) are common, although significant exceptions exist. Pouissons play crucial roles in aquatic ecosystems, serving as both prey and predators, and contributing to nutrient cycling. For humans, pouissons represent a significant source of food and are also important in recreational activities like fishing. The study of pouissons falls under the discipline of ichthyology.