25 Difference between Invertebrates and Vertebrates (With Table)

Vertebrates and invertebrates are the main sub-divisions of animals on earth. This type of classification is based on animals with and without backbones.

Other classification of animals in the Kingdom Animalia are multicellular and heterotrophs organisms. Understanding the characteristics of invertebrates and vertebrates will help to tell their differences.

So, what is the main difference between invertebrates and vertebrates? The former refers to animals that do not have a vertebral column while the latter refers to those animals that contain a vertebral column.

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Comparison Table (Invertebrates and Vertebrates)

Basic Terms Invertebrates Vertebrates
Meaning Animals without backbone Animals with backbone
Size Small and slow-moving Tend to vary in size from small to big
Body Symmetry Bi-radial, Radial or absent Bilateral
Body Structure Simple with the unorganized nervous system Complex with highly specialized organs
Skin Layers Have one layer of skin Have two layers of skin i.e Epidermis and Dermis
Types of Eyes Compounds eyes are present but not the outgrowth of the brain Compound eyes are absent but the eyes are the outgrowth of the brain
Body Temperatures Cold-Blooded Animals Warm-Blooded Animals
Reproduction Asexual reproduction is predominant Sexual reproduction is predominant
Regeneration of Power Good Poor
Segmental Nerve Root Dorsal and ventral roots not separated Dorsal and ventral roots are separated
Nerve Cord Double ventral with ganglia Single dorsal without ganglia
Brain Absent or above the pharynx Dorsal to pharynx in the head
Nervous System Solid Hollow
Respiration Body surface, gills, and trachea Gills or lungs
Dorsal Blood Vessel Blood flows anteriorly Blood flows posteriorly
Hepatic portal system Absent Present
Hemoglobin In plasma or absent In red blood corpuscles
Heart Location Dorsal, lateral, or absent Ventrally placed
Blood vascular system Open, closed, or absent Closed and much developed
Anus Open on the last segment or absent Differentiated and open on the last segment
Pharyngeal gill-slits Absent Present at some stages in life
Gut position Dorsal to the nerve cord Ventral to the nerve cord
Notochord Absent Present
Limbs Derivation From the same segment From several segments
Grade of organization Protoplasmic or organ system Organ system

What Are Invertebrates?

These are animals without a backbone. Invertebrates are abundantly found on earth and live in most habitats. The animals are cold-blooded since their internal body temperature is regulated by the surrounding.

Invertebrates do not develop notochord. Examples of invertebrates are starfish, sponges, jellyfish, worms, mollusks, and arthropods.

The absence of a strong exoskeleton makes invertebrates small and slow in movement. The respiration occurs through the skin surfaces and gills.

Characteristics of Invertebrates

  1. Cold-blooded animals
  2. Lack notochord
  3. Breathe through skin surfaces and develop gills
  4. Have bi-radial body symmetry
  5. Have a solid nervous system

What Are Vertebrates?

Vertebrates are animals with a backbone. These animals belong to the phylum Chordata of the kingdom Animalia. Vertebrates have organized body systems and structures.

Examples of vertebrates are fish, human beings, reptiles, amphibians, birds, and other mammals. The presence of the spinal cord, notochord, and vertebral column is what distinguishes vertebrates.

Embryos have a notochord that occurs in the middle of the dorsal line body and is later replaced by the spinal column during the adulthood stage.

Characteristics of Vertebrates

  1. Have a backbone, notochord, and vertebral column
  2. Animals are warm-blooded
  3. Breathe through lungs and gills
  4. Have bilateral body symmetry
  5. Have the hollow nervous system

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Main Differences between Vertebrates and Invertebrates

  1. Vertebrates possess notochord while invertebrates lack a notochord
  2. Vertebrates are large animals whereas invertebrates are small and slow-moving animals
  3. Invertebrates have a solid nervous system while vertebrates have a hollow nervous system
  4. Invertebrates have dorsally located heart while vertebrates have ventral heart position
  5. Vertebrates have a closed circulatory system whereas invertebrates have an open circulatory system
  6. Vertebrates are warm-blooded animals whereas invertebrates are cold-blooded animals
  7. Invertebrates lack a hepatic portal system while vertebrates have a hepatic portal system
  8. Vertebrates have two layers of the skin whereas invertebrates have a single layer of skin
  9. Vertebrates reproduce sexually while invertebrates through asexual reproduction
  10. Invertebrates have compound eyes while vertebrates lack compound eyes

Similarities between Invertebrates and Vertebrates

  1. Both belong to kingdom Animalia
  2. Both have gills
  3. Both have a nervous system
  4. Both have heart
  5. Both show bilateral symmetry
  6. Both exhibit movement
  7. Both can adapt to the environment
  8. Both live on land and in water
  9. Both can reproduce and respire


Understanding the comparison between invertebrates and vertebrates is quite important. The information will spearhead a proper understanding of the phylum Chordata in Kingdom Animalia.

Vertebrates are higher animals due to the presence of backbone and invertebrates are lower animals in the kingdom Animalia.

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