What is the special features of Holocephali?

What is the special features of Holocephali?

Key Characters of Holocephali Endoskeleton cartilaginous, often calcified. Persistent (unconstricted) notochord; poorly developed vertebrae. Holostylic jaw suspension, i.e., the upper jaw is immovably united with cranium, hence the name holocephali. Teeth united to form crushing plates, devoid of enamel.

What is the purpose of the cloaca in sharks?

The cloacal opening located on the ventral surface between the pelvic fins. It receives the products of the intestine, the urinary and the genital ducts. The name cloaca, meaning sewer, seems quite appropriate.

Where are Elasmobranch found?

These fish are widely distributed in tropical and temperate waters. Many fish maintain buoyancy with swim bladders.

Do Holocephali have teeth?

Holocephali differ from Euselachii in respect of the number of gills (they have one gill slit compared with 5–7 in sharks, skates, and rays) and in the fact that their teeth are fused to form plates.

What is the common name of Holocephali?

chimaera, (subclass Holocephali), also spelled chimera, also called ghost shark, any of numerous cartilaginous fishes related to sharks and rays in the class Chondrichthyes but separated from them as the subclass (or sometimes class) Holocephali.

Is Holocephali extinct?

Holocephali (=”complete heads”) is a class of mostly extinct species of cartilaginous fish.

Do birds poop and pee out of the same hole?

Birds, unlike mammals, do not have separate exits for urine and feces. Both waste products are eliminated simultaneously through the cloaca. It turns out that not all birds pee and poop simultaneously. Ostriches, for example, though they also expel waste through the cloaca, disgorge liquid urine before defecating.

What are Claspers used for?

Claspers in chondrichthyans are specialized elongations on the posterior side of male pelvic fins that are used for sperm transfer during copulation.

Do sharks pee through their skin?

It’s meaty and mild — but has to be soaked well before it’s eaten because sharks urinate through their skin.

What is the meaning of Holocephali?

Definition of Holocephali. : a subclass of Chondrichthyes that is sometimes made a separate class, includes the recent chimaeras and certain chiefly extinct related fishes some of which date from Devonian time, and is distinguished by a cartilaginous skeleton, gill clefts covered by a fold of skin, high compressed head with small narrow mouth…

What is a cloaca and what is it for?

What is a cloaca? Early in the development of a female fetus, the tissue that is supposed to become the intestinal, genital, and urinary tracts are together in one unit known as a “cloaca.” These three typically separate as a pregnancy proceeds, creating the anus, the vagina, and the urethra.

How do holocephalians move?

These fishes move by using sweeping movements of their large pectoral fins. Extant Holocephalians have long, slender tails and live close to the seabed feeding on benthic invertebrates. They lack a stomach, their food moving directly into the intestine.

What is a cloacal malformation?

Cloacal malformations result when a baby girl’s vagina, urinary tract, and anus do not separate from one another completely. What is a cloaca? Early in the development of a female fetus, the tissue that is supposed to become the intestinal, genital, and urinary tracts are together in one unit known as a “cloaca.”