24 Differences between Invertebrates and Vertebrates

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The animal kingdom has been divided into two major groups: Invertebrates (Non-Chordates) and Vertebrates (Chordates). Invertebrates are those that do not possess a vertebral column or backbone while Vertebrates are those where vertebral column or backbone is present.

Differences between Invertebrates and Vertebrates

These two groups have some differences as follows:

S.N.

 Characteristics Invertebrates (Non-Chordates)

Vertebrates (Chordates)
1. Symmetry Radial, Bi-radial or Absent Bilateral
2. Metamerism True or pseudo metamerism or Absent True metamerism
3. Post-anal tail Absent Usually Present
4. Grade of organization Protoplasmic or organ-system Organ System
5. Germ Layers Two (diploblastic), Three (Triploblastic) or Absent Three (Triploblastic)
6. Coelom Acoelomate, pseudocoelomate or Truly coelomate Truly coelomate
7. Limbs derivation From the same segment From several segments
8. Notochord Notochord or Backbone Absent Present at some stage or replaced by a backbone made of ring-like vertebrae
9. Gut position Dorsal to the nerve cord Ventral to the nerve cord
10. Pharyngeal gill-slits Absent Present at some stage of life
11. Anus Opens on the last segment or Absent Differentiated and opens before the last segment
12. Blood vascular system Open, Closed or Absent Closed and much developed
13. Heart Dorsal, Lateral or Absent Ventrally placed
14. Dorsal blood vessel Blood flows anteriorly Blood flows posteriorly
15. Hepatic portal system Absent Present
16. Hemoglobin In plasma or Absent In red blood corpuscles
17. Respiration Through body surface, gills or tracheae Through gills or lungs
18. Nervous System Solid Hollow
19. Brain Above pharynx or Absent Dorsal to pharynx in head
20. Nerve cord Double, ventral, usually bearing ganglia Single, dorsal, without ganglia
21. Segmental nerve roots Dorsal and ventral roots not separate Dorsal and ventral roots separate
22. Reproduction Asexual reproduction predominant Sexual reproduction predominant
23. Regeneration power Usually good Usually poor
24. Body temperature Cold-blooded Cold or warm-blooded

References

  1. Kotpal RL. 2017. Modern Text Book of Zoology- Invertebrates. 11th Edition. Rastogi Publications.
  2. Jordan EL and Verma PS. 2018. Invertebrate Zoology. 14th Edition. S Chand Publishing.

Differences between Invertebrates and Vertebrates

About Author

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Sagar Aryal, PhD

Sagar Aryal is a microbiologist and a scientific blogger. He completed his Ph.D. degree in Microbiology from the Central Department of Microbiology, Tribhuvan University, Kathmandu, Nepal in 2025. He was awarded the DAAD Research Grant to conduct part of his Ph.D. research work for two years (2019-2021) at Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarbrucken, Germany. Sagar is interested in research on actinobacteria, myxobacteria, and natural products. He is the Research Head of the Department of Natural Products, Kathmandu Research Institute for Biological Sciences (KRIBS), Lalitpur, Nepal. Sagar has more than 15 years of experience in blogging, content writing, and SEO. Sagar was awarded the SfAM Communications Award 2015: Professional Communicator Category from the Society for Applied Microbiology (Now: Applied Microbiology International), Cambridge, United Kingdom (UK). Sagar is also the ASM Young Ambassador to Nepal for the American Society for Microbiology since 2023 onwards.

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