How many species of Elasmobranchii are there?

How many species of Elasmobranchii are there?

In total, there are about 869+ extant species of elasmobranchs, with about 400+ of those being sharks and the rest skates and rays.

What makes a elasmobranch?

The term elasmobranch refers to the sharks, rays, and skates, which are cartilaginous fishes. These animals have a skeleton made of cartilage, rather than bone. These animals are collectively referred to as elasmobranchs because they are in the Class Elasmobranchii.

Is Elasmobranchii a class?

Cartilaginous fishesElasmobranchii / Class

Are birds Gnathostomata?

Gnathostomes later evolved into all tetrapods (animals with four limbs) including amphibians, birds, and mammals. Early gnathostomes were jawed fishes that possessed two sets of paired fins, which increased their ability to maneuver accurately.

Are dogfish Elasmobranchii?

Squaliformes (dogfish sharks) is a large elasmobranch order with six families (Centrophoridae, Dalatiidae, Etmopteridae, Oxynotidae, Somniosidae, and Squalidae) and over 100 species. A previous study suggested all squaliforms share one basic body plan unlike most other shark orders that have body shape diversity.

What is agnatha and Gnathostomata?

The key difference between Agnathans and Gnathostomata is that Agnathans are organisms that do not possess a jaw while Gnathostomata are organisms with jaws. This key difference plays a major role in the form of feeding they undergo. Agnathans are jawless fish. Gnathostomata are fish that have jaws.

What is Gnathostomata give example?

The group, Gnathostomata, is traditionally a infraphylum, broken into three top-level groupings: Chondrichthyes, or the cartilaginous fish; Placodermi, an extinct grade of armored fish; and Teleostomi, which includes the familiar classes of bony fish, birds, mammals, reptiles, and amphibians.

Is holocephali a class?

Cartilaginous fishesHolocephali / Class

Which gland is present only in male?

testes
The short answer is testes. The testes are found in the male reproductive system only.

What is Agnatha in zoology?

Agnatha (/ˈæɡnəθə, æɡˈneɪθə/, Ancient Greek ἀ-γνάθος ‘without jaws’) is an infraphylum of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present (cyclostomes) and extinct (conodonts and ostracoderms) species.

What is Gnathostomata in zoology?

Gnathostomata /ˌnæθoʊˈstɒmətə/ are the jawed vertebrates. The term derives from Greek: γνάθος (gnathos) “jaw” + στόμα (stoma) “mouth”. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates.

Is Holocephali a class?