![Picture](/uploads/4/8/2/6/48264381/413574106.png)
Chordata Phylum Main Characteristics (vertebrates):
These features appear during some
stage during their development.
These features appear during some
stage during their development.
- Pharyngeal Slits - A series of openings that connect the inside of the throat to the outside of the neck. In organisms that live in aquatic environments , the pharyngeal slits allow the water to exit during feeding. In organisms that do not live in an aquatic environment this feature is only present during embryonic stages.
- Dorsal Nerve Cord - Bundle of nerve fibers which runs down the dorso. It connects the brain with the lateral muscles and other organs.
- Notochord- flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species. It is replaced by the vertebral column in most adult vertebrates.
- Post-anal Tail- An extension of the body past the anal opening. In some terrestrial vertebrates, the tail also helps with balance, courting, and signaling when danger is near. In humans and apes, the post-anal tail is present during embryonic stages, but is vestigial as an adult.
Class Reptilia:
Habitat: Reptiles live anywhere in the world except freezing cold regions. They can even live in the ocean and deserts. Exoskeleton: They do have an exoskeleton such as a turtle’s shell. Respiratory Organs: They have lungs. Locomotion: They all use their legs to move, but they are adapted to each species need. Heart: They have a 3 and ½ chambered heart. Aortic Arch: They have 3 aortic arches. Mode of Reproduction: Most of the species reproduce sexually but there is one specie of a snake that can reproduce asexually. Fertilization: They fertilize internally. Class Amphibia:
Habitat: They can be found in forests, streams, rivers. Exoskeleton: They don’t have an exoskeleton. Respiratory Organs: Both amphibians that live in water and land have skin but the ones that live in water breathe through their skin and the ones on land by lungs. Locomotion: Powerful hind legs and others walk and swim by using side-to-side movement. Heart: They have three chambered hearts. Aortic Arches: They have four aortic arches. Mode of Reproduction: They reproduce sexually. Fertilization: They fertilize internally and externally depends on the specie. |
Class Mammalia:
Habitat: Mammals can live anywhere like the ocean and the land. Exoskeleton: A mammal doesn’t have an exoskeleton. Respiratory Organs: The organs are; the lungs, bronchi, trachea, larynx, and the nasal chamber. Locomotion: There are four limbs that are adapted for specific habitats. Heart: They have a four chambered heart. Aortic Arch: Only three after they reach adulthood. Mode of Reproduction: All mammals reproduce sexually. Fertilization: They all fertilize internally. |
Class Chondrichthyes: Cartilaginous Fishes
Habitat: Most of them live in salt water but some of them live in fresh water. Respiratory Organs: They only use the gills as an organ to breathe. Locomotion: They move by using fins and tails. Heart: It consists of a heart with 2 chambers. Aortic Arch: They can have 10-12 aortic arches. Mode of Reproduction: They produce sexually. Fertilization: They all have internal fertilization. Exoskeleton: It is made up of cartilage. Class Aves: Birds
Habitat: Birds live in various different habitats such as; woodlands, rain forest wetland, coastal and etc. Exoskeleton: They don’t have an exoskeleton. Respiratory Organs: They have lungs, and air sacs. Locomotion: They have wings for flying, legs for perching, catching prey, and walking. Heart: Birds have a four chambered heart. Aortic Arch: There is one main arch, because the left side arch doesn’t develop. Mode of Reproduction: They reproduce sexually. Fertilization: They are fertilized internally. |
Class Agnatha: Jawless Fish
Habitat: They live in fresh water river, lakes, the bottom of the ocean, sea caves, and even in mud. Exoskeleton: It has an endoskeleton instead of an exoskeleton. Respiratory Organs: Gills Locomotion: They swim in a rippling way. Heart: They have a two chambered heart. Aortic Arch: They can have up to 15 aortic arches. Mode of Reproduction: They reproduce sexually. Fertilization: They mostly reproduce externally by laying their eggs. |