Chordates
What are Chordates?
Chordates are a phylum of animals that possess, at some stage in their life cycle, a notochord, dorsal nerve cord, pharyngeal slits, and post-anal tail. Chordates include vertebrates such as mammals, birds, reptiles, and fish, as well as some invertebrates like lancelets and tunicates.
Animals with a Backbone or Similar Support
Chordates are animals that have a special structure called a notochord at some point in their life. This group includes all animals with backbones, like fish, birds, mammals, and reptiles, as well as some without backbones, like sea squirts.
What Makes Chordates Special?
All chordates share these traits at some point in their life:
- Notochord: A flexible rod that provides support; in many chordates, this becomes a backbone.
- Nerve Cord: Runs along their back and helps send signals through the body.
- Pharyngeal Slits: Openings near the throat that help with breathing or feeding in early development.
- Post-Anal Tail: A tail that extends beyond the end of their body.
Types of Chordates
- Vertebrates: Animals with backbones, like mammals, birds, reptiles, Amphibians, and fish.
- Tunicates: Soft-bodied sea creatures that look like jelly but have chordate features as larvae.
- Lancelets: Small, fish-like animals without a backbone that live buried in sand.
Examples of Chordates
- Fish: Like salmon and sharks, which have gills and live in water.
- Birds: Like eagles and penguins, known for feathers and flight.
- Mammals: Like humans and whales, which feed their babies with milk.
- Amphibians: Like frogs and salamanders, that live both in water and on land.
- Reptiles: Like snakes and turtles, with scaly skin.
Where They Live
Chordates can live almost anywhere:
- Oceans: Fish, whales, and tunicates thrive underwater.
- Forests and Grasslands: Mammals and birds find food and shelter.
- Deserts: Reptiles like lizards and snakes survive in dry heat.
Challenges for Chordates
- Habitat Loss: Forests, oceans, and wetlands are being destroyed.
- Pollution: Trash and chemicals harm both land and water chordates.
- Climate Change: Warmer temperatures affect migration, food availability, and reproduction.