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Chondrichthyes (/ k ɒ n ˈ d r ɪ k θ i iː z /; 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.
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.
The following is the full list of the extant species in Class Chondrichthyes, or the cartilaginous fish. Members of this class have a backbone , gills , no swim bladder , jaws , and a skeleton made of cartilage , a soft, strong material as a replacement for bone .
Batomorphi is a clade of cartilaginous fishes, commonly known as rays, this taxon is also known as the superorder Batoidea, but the 5th edition of Fishes of the World classifies it as the division Batomorphi. [2] They and their close relatives, the sharks, compose the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes ...
Each gill is supported by a cartilaginous or bony gill arch, [1] which helps to maintain the gill's surface area. Bony fish (osteichthyans, mostly teleost ray-finned fish) have four pairs of arches, cartilaginous fish (chondrichthyans) have five to seven pairs, and the more basal jawless fish ("agnathans") have up to seven.
Male cartilaginous fishes (sharks and rays), as well as the males of some live-bearing ray finned fishes, have fins that have been modified to function as intromittent organs, reproductive appendages which allow internal fertilization. In ray finned fish, they are called gonopodia or andropodia, and in cartilaginous fish, they are called claspers.
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. In practice, fish anatomy and physiology complement each other, the former dealing with the structure of a fish, its organs or ...
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.