Summary
Vertebrates have a backbone; invertebrates, which are over 95 percent of animals, do not.
In depth
Vertebrates (about 5 percent of species) have a backbone of vertebrae, a skull and closed circulation. Invertebrates include sponges, cnidarians, worms, molluscs, arthropods and echinoderms. It is a convenient grouping, not an evolutionary one.
Vertebrates have an internal skeleton of bone or cartilage. Invertebrates are far more diverse. Many invertebrates have complex behaviour.
Remember: 'invertebrate' is not a natural group.
Invertebrates make up about 95 percent of animal species, and range from sponges to insects, with no shared backbone and no single origin. Vertebrates include fish, amphibians, reptiles, birds and mammals, and have a cranium, neural crest cells and, in most, a vertebral column that replaces the notochord; they came from chordate ancestors over 500 million years ago. Vertebrate features such as endoskeletons, closed circulation and complex brains allowed large size and active lifestyles.
Some invertebrates rival vertebrates in complexity, such as cephalopods and social insects. Invertebrates are critical for pollination, soils, food webs and fisheries, yet are less studied in conservation. The distinction is a convenience, since invertebrates are not a natural group.
Frequently asked questions
What is Vertebrates and Invertebrates?
Vertebrates have a backbone; invertebrates, which are over 95 percent of animals, do not.
Which area of biology covers Vertebrates and Invertebrates, and how advanced is it?
Vertebrates and Invertebrates is one of the 53 topics in Zoology & Animal Diversity. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Animal Kingdom, Germ Layers, Insects.
Why does Vertebrates and Invertebrates matter?
Many research findings come from invertebrates such as fruit flies, nematodes and sea urchins.
Can you give an example of Vertebrates and Invertebrates?
Octopuses are invertebrates with complex brains.
What should I learn before Vertebrates and Invertebrates?
Vertebrates and Invertebrates is a Beginner topic, so no earlier topic is required. Other Beginner topics in Zoology & Animal Diversity that pair well with it include Animal Kingdom, Sponges, Cnidarians.
What topics are related to Vertebrates and Invertebrates?
The closest topics to Vertebrates and Invertebrates are Animal Kingdom, Germ Layers, Insects, Mammals. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Vertebrates and Invertebrates?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Vertebrates and Invertebrates. To practise the whole of Zoology & Animal Diversity, use the Zoology & Animal Diversity quiz.
How is Vertebrates and Invertebrates different from Animal Kingdom?
Vertebrates and Invertebrates: Vertebrates have a backbone; invertebrates, which are over 95 percent of animals, do not. Animal Kingdom: Multicellular heterotrophic eukaryotes without cell walls that typically move and ingest food. Read both side by side and note what each one explains.
How should I study Vertebrates and Invertebrates step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Animal Kingdom and explain the difference aloud. Finally, take the Zoology & Animal Diversity quiz and come back to this page for any question you miss.