Search results
Results from the WOW.Com Content Network
Chondrichthyes (/ kɒnˈdrɪkθiiːz /; from Ancient Greek χόνδρος (khóndros) 'cartilage' and ἰχθύς (ikhthús) 'fish') is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fish, which have ...
Distinctively, these fish have no jaws. [15] Cartilaginous fish such as sharks also have simple, and presumably primitive, skull structures. The cranium is a single structure forming a case around the brain, enclosing the lower surface and the sides, but always at least partially open at the top as a large fontanelle.
Sharks are cartilaginous fish. The skeleton of a shark is mainly made of cartilage. They belong to the class of Chondrichthyes. In particular, the endoskeletons are made of unmineralized hyaline cartilage which is more flexible and less dense than bone, thus making them expel less energy at high speeds.
Fish physiology. When threatened, the toxic pufferfish fills its extremely elastic stomach with water. [1] Fish physiology is the scientific study of how the component parts of fish function together in the living fish. [2] It can be contrasted with fish anatomy, which is the study of the form or morphology of fishes.
Pleurotremata. Selachii. Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha[ 1 ] (or Selachii) and are the sister group to the Batoidea (rays and kin).
Cartilaginous fish, such as sharks and rays also lack a true maxilla. Their upper jaw is instead formed from a cartilagenous bar that is not homologous with the bone found in other vertebrates. [14] Some fish have permanently protruding upper jawbones called rostrums. Billfish (marlin, swordfish and sailfish) use rostrums (bills) to slash and ...
Chimaeras are soft-bodied, shark-like fish with bulky heads and long, tapered tails; measured from the tail, they can grow up to 150 cm (4.9 ft) in length. Like other members of the class Chondrichthyes, chimaera skeletons are entirely cartilaginous, or composed of cartilage. Their skin is smooth and relatively free of scales or unique features ...
Elasmobranchii (/ ɪˌlæzməˈbræŋkiaɪ / [6]) is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins ...