The key difference between vertebrates and invertebrates is that vertebrates have a backbone, while invertebrates lack a backbone.
What are Vertebrates?
Vertebrates are animals that possess a vertebral column, also known as a backbone or spine. This structural feature is a defining characteristic of vertebrates. The vertebral column is made up of individual bones called vertebrae, which encase and protect the spinal cord. Vertebrates belong to the subphylum Vertebrata within the phylum Chordata.
Examples
Vertebrates are part of a diverse group that includes animals like mammals, birds, reptiles, amphibians, and fish. They often exhibit more complex and specialized body systems compared to invertebrates, with well-developed nervous systems, circulatory systems, and often highly specialized sensory organs.
What are Invertebrates?
Invertebrates are animals that do not possess a vertebral column or backbone. They make up a vast and diverse group of creatures found in various habitats around the world. Invertebrates come in a wide range of sizes, shapes, and forms, and they encompass a significant portion of the animal kingdom.
Examples
Invertebrates include insects, spiders, worms, mollusks (like snails and clams), jellyfish, and crustaceans (such as crabs and shrimp). These animals play important roles in ecosystems, performing functions like pollination, and decomposition, and serving as food sources for other organisms.
Vertebrates vs Invertebrates
The main difference between vertebrates and invertebrates is given below:
| Aspect | Vertebrates | Invertebrates |
| Definition | Animals with a vertebral column (backbone). | Animals lacking a vertebral column (backbone). |
| Body Symmetry | Bilateral symmetry in most cases. | Varied symmetry: bilateral, radial, asymmetrical. |
| Nervous System | Well-developed central nervous system. | Varies from simple nerve nets to complex systems. |
| Circulatory System | Endoskeleton is made of bones/cartilage. | Varied circulatory systems, some open, some not. |
| Respiration | Gills, lungs, or both for gas exchange. | Various methods including gills, tracheae, skin. |
| Reproduction | Sexual reproduction is common. | Varied methods: sexual, asexual, hermaphroditic. |
| Exoskeleton/Endoskeleton | Humans, birds, fish, mammals, and reptiles. | Exoskeleton made of chitin or none at all. |
| Mobility | Limbs or fins for movement. | Various modes: crawling, swimming, flying, etc. |
| Size Range | Range from tiny frogs to large whales. | Range from microscopic to relatively large. |
| Examples | Insects, mollusks, worms, arachnids, and jellyfish. | Various methods including gills, tracheae, and skin. |