baliqlar

Baliqlar are aquatic vertebrates that include most of the world’s fish species. They are gill-bearing, craniate animals that typically live in water and are ectothermic. With more than 32,000 described species, baliqlar form the largest group of vertebrates by species, occupying a wide range of habitats from the deep ocean to high-altitude streams.

Taxonomically, baliqlar comprise several major groups. Jawless fish (Agnatha) include lampreys and hagfishes, representing early jawless lineages. Most living baliqlar are jawed fish (gnathostomes), divided into cartilaginous fish (Chondrichthyes) — sharks, rays, and chimaeras — and bony fish (Osteichthyes). Osteichthyes are further categorized into ray-finned fish (Actinopterygii) and, less commonly, lobe-finned fish (Sarcopterygii), the latter including the ancestors of terrestrial vertebrates.

Anatomically, baliqlar typically have fins supported by lepidotrichia or cartilaginous elements, scales of various types, and a lateral line system for detecting movement and vibration in water. Most species possess a swim bladder to regulate buoyancy.

Reproduction and development vary widely. Many baliqlar reproduce by external fertilization and lay eggs, while others bear live young. Numerous species undertake migrations, such as anadromous salmon moving between freshwater and saltwater, or catadromous eels.

Ecology and human use: baliqlar occupy a central position in aquatic ecosystems as predators, prey, and contributors to nutrient cycling. They are also a major source of food and income for humans, supporting global fisheries and aquaculture.

Conservation concerns include overfishing, bycatch, habitat degradation, and climate change, prompting management measures like catch quotas, size limits, protected areas, and sustainable fishing practices.