Members of the Chordata phylum,have at some point:
notochord- cartilaginous rod running underneath, and supporting, the nerve cord
dorsal nerve chord - a bundle of nerve fibers which runs down the "back". It connects the brain with the lateral muscles and organs, post anal tail - an extension of the body past the anal opening
pharyngeal slits ( a series of openings that connect the inside of the throat to the outside of the neck, often used as gills)aoThe chordata phylum is one of the most known phyla. Humans are part of this phylum. It contains mostly vertebrates but it does include invertebrates.
Chordate Circulatory System

Chordates have a closed circulatory system which can be either single or double looped.

Closed circulatory systems (evolved in echinoderms and vertebrates) have the blood closed at all times within vessels of different size and wall thickness.

Common to Molluscs and Arthropods, Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood. The resulting blood flow is slow.

FIsh, such as this clownfish have a single loop circulatory system. They have body and gill capillaries as well as a heart, an