Kõhrkaladel

Kõhrkaladel, scientifically known as Chondrichthyes, represent a class of cartilaginous fish that includes sharks, rays, skates, and chimaeras. Unlike bony fish (Osteichthyes), their skeletons are composed entirely of cartilage rather than bone. This unique skeletal structure grants them certain advantages, such as flexibility and buoyancy.

These fish are characterized by a number of distinct features. They possess placoid scales, which are small, tooth-like structures that provide protection and reduce drag. Most kõhrkaladel have five to seven gill slits on each side of their head, which are typically exposed and not covered by an operculum. Their jaws are hinged, allowing for a wide gape and the efficient capture of prey. Many species also have clasped pectoral fins, contributing to their maneuverability.

Reproduction in kõhrkaladel is varied. Some species lay eggs (oviparous), while others give birth to live young (viviparous or ovoviviparous). Internal fertilization is a common characteristic, with males possessing claspers, modified pelvic fins used for sperm transfer.

Kõhrkaladel inhabit a wide range of marine environments, from shallow coastal waters to the deep ocean. Their diets are diverse, encompassing a variety of prey depending on the species, including other fish, invertebrates, and plankton. Despite their ancient lineage, many species of kõhrkaladel face significant threats from overfishing and habitat destruction, leading to declining populations worldwide.