Chondrichthyes are aquatic vertebrates with paired fins, paired nares, placoid scales, conus arteriosus in the heart, and a lack of opercula and swim bladders. Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates.

2024年12月27日 · chondrichthyan, (class Chondrichthyes), any member of the diverse group of cartilaginous fishes that includes the sharks, skates, rays, and chimaeras. The class is one of the two great groups of living fishes, the other being the osteichthians, or bony fishes. The name Selachii is also sometimes used for the group containing the sharks.

2024年12月27日 · During their flowering, the placoderms evidently gave rise to the Osteichthyes (the bony fishes) and the Chondrichthyes (the cartilaginous fishes). Even though the lines of evolution remain to be discovered, it seems quite clear that the two groups evolved independently, the Chondrichthyes appearing much later than the Osteichthyes.

Most chondrichthyans are marine species. Only 5% (approximately 45 species) are restricted to freshwater, such as the giant freshwater stingray, Himantura chaophraya (Fowler et al., 2005; Helfman et al., 2009). Others enter estuaries and freshwater sporadically, often to breed.

Chondrichthyes is a class of jawed fishes having a cartilaginous skeleton. The class includes a diverse group of fishes including sharks, rays, skates and chimaeras. They are mostly marine fishes. The other group of fishes are bony fishes, which are included in the class Osteichthyes.

2024年4月12日 · Chondrichthyes, derived from the Greek words “chondr” meaning cartilage and “ichthys” meaning fish, refers to a class of jawed fishes characterized by their cartilaginous skeletons. Unlike the bony fishes known as Osteichthyes, which have skeletons primarily composed of bone tissue, Chondrichthyes have skeletons primarily composed of cartilage.

The Chondrichthyes or cartilaginous fishes are a major class of jawed fish that includes the sharks, rays, and skates, and whose skeleton is characterized by rubbery cartilage, which is very light and flexible, rather than bone, as in the bony fishes (class Osteichthyes (such …

2023年5月29日 · Chondrichthyes are jawed fish with paired fins, paired nostrils, scales, two-chambered hearts, and skeletons made of cartilage (rather than bone). They are divided into two subclasses: elasmobranchii (sharks, rays and skates) and Holocephali (chimaera, sometimes called ghost sharks).

Chondrichthyes are cartilaginous fish within the vertebrate lineage that are divided in two sub clusters: Elasmobranchs including sharks, rays and skates and Holocephali including the chimaeras.

The chondrichthyan meaning has a diverse group of cartilaginous fishes. The best Chondrichthyes examples are skates, chimaeras, sharks, and rays. The Chondrichthyan classes are widely dividing the living fish groups into two great …