MARIA GARCIAAND

SASHA ESPINOLA

Chordates

Phylum Chordata

Classification of Chordates include characteristics such as:Dorsal, hollow nerve cord

NotochordPharyngeal pouchesTail that extends beyond the anus

Structure of Chordate

Notochord: Supporting rod that runs through the body just below the nerve cord.

Some chordates only have an notochord when they are embryos.

Pharyngeal Pouches: paired structures in the pharynx region of the throat.

Some chordate, like fishes and amphibians, slits connect to the outside of the body that develop gills

All chordates have a tail that extends beyond the anus it can contain bone and muscle and is used in swimming by many aquatic species

Vertebrates

More than 99% of all chordates are placed in the sub phylum vertebrata and they are called vertebrates

Has a supporting structure know as a vertebral column, or backbone

Dorsal hollow nerve cord is the spinal cordAs chordates develop the front end of the spinal

chord grows into a brain, the backbone replaces the notochord, and is made of individual segments called vertebrae that protects the spinal chord.

Similarities and Differences of Anthropoids and Chordates Vertebrates

Arthropods Vertebrates SimilaritiesTheir exoskeleton needs to be shed periodically

The skeleton grows as the animal grows

Endoskeleton protects and supports the animals body and gives muscles a place to attach

The skeleton is made up of non living material

Skelton contains living cells as well as living materials

Nonvertebrate Chordates

Vertebrates and nonvertebrates evolved from a common ancestor because of the similarities in structure and embryological development

Fossil from the Cambrian period states that they divided more than 550 million years ago

Tunicates

Belong to the subphylum Urochordata, filter-feeders.

The larva form of a tunic has all the chordate characteristics, adult tunics on the other hand don’t have a notochord or a tail.

Lancelets

Belong to the subphylum Cephalochordata.

They’re small fish-like creatures that live on the sandy ocean bottom.

Adult Lancelets has a defined head region that contains a mouth, it opens into a long pharynx with up to a 100 pairs of gill slits.

Lancelets cont.

Water passes through the pharynx and a sticky mucus catches the food particles. Then, the Lancelets swallows the mucus into the digestive track.

Lancelets use the gills in the pharynx for gas exchange, they’re so thin that they can exchange gases through their body surface.

Lancelets have a closed circulatory system, meaning their blood flows within, the walls of the blood vessels pump blood throughout the Lancelets tiny body.

Lancelets cont. part deux

The fish like motion of Lancelets results from contracting muscles that are organized into v-shaped units, they’re paired on either side of the body.

Often live with their bodies half buried into the sand.

They contain no fins of legs, this is why they have paired muscles along their body