What are Chordates?

Chordates represent a diverse group of animals characterized by the presence of a notochord at some stage of their life cycle. The notochord serves as a support structure and is replaced by the vertebral column in vertebrates. Some invertebrates are also chordates because they have a notochord. But they lack a proper backbone and are thus called invertebrates. Those invertebrates which are included in chordates are tunicates and lancelets.

Characteristics of Chordates

Chordates are considered one of the most advanced groups of animals, showing a high level of complexity and specialization:

• They can be cold-blooded or warm-blooded.
• They are true coelomates and triploblastic.
• Post-anal tail is present for body balancing.
• Exoskeleton is present in some chordates like tortoises while the endoskeleton is present in all.
• The regeneration power of chordates is poor.
• They possess a complete or incomplete digestive system.
• The gut is present ventral to the nerve cord.
• Aquatic chordates respire through gills, while terrestrial species utilize lungs.
• Some chordates, such as amphibians, can also respire through their skin.

Difference between Chordates and Non-Chordates: Chordates and Non-Chordates are two groups of animals based on the presence or absence of a notochord. Notochord is a flexible rod-like structure that provides support. Chordates possess a notochord at some stage of their life. Non-chordates, on the other hand, lack a notochord. In this article, we will cover key distinctions between chordates and non-chordates in detail.