Urocordados and Cefalocordados Quiz

The Urocordados are a type of marine sesseid animal that can live alone or in colonies. Their size can vary from a few millimeters to 10 centimeters.

Their representatives are the salpas and ascidias.

The body of the Urocordados is covered by a thick, named tunic, made of the marine polysaccharide tunicina. This layer also can be called tunicated.

Two openings exist on the tunic: the inhalant opening, through which water enters the animal's body, and the exhalant opening, through which water returns to the environment.

The Urocordados feed by filtering water particles that adhere to a mucous secretion produced in a sulcus on the throat, the endolymphatic sac.

The Urocordados' circulatory system is partially open and the blood flows through large blood vessels, called sinuses, where gas exchanges take place.

During the larval stage, there is a nerve tube, located dorsally, from which nerves branch to various organs. In the adult stage, this structure reduces to a nerve cord located under the throat, from which the nerves branch.

The Urocordados reproduce sexually, with the majority of species being monosexual. Some species can reproduce asexually by budding.

Cefalocordados are a type of fish-like marine animal. They have a flat body with a sharp edge on the lateral side.

Cefalocordados bury themselves in sand, in a vertical position, and leave their mouth exposed.

Their anatomy is similar to that of a fish, but they do not have a separate head.

One distinctive feature of cefalocordados is the presence of cirros bucais, or fishy cirrus filaments, around their mouth.