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
MeaningAnimals without backboneAnimals with backbone
SizeSmall and slow-movingTend to vary in size from small to big
Body SymmetryBi-radial, Radial or absentBilateral
Body StructureSimple with the unorganized nervous systemComplex with highly specialized organs
Skin LayersHave one layer of skinHave two layers of skin i.e Epidermis and Dermis
Types of EyesCompounds eyes are present but not the outgrowth of the brainCompound eyes are absent but the eyes are the outgrowth of the brain
Body TemperaturesCold-Blooded AnimalsWarm-Blooded Animals
ReproductionAsexual reproduction is predominantSexual reproduction is predominant
Regeneration of PowerGoodPoor
Segmental Nerve RootDorsal and ventral roots not separatedDorsal and ventral roots are separated
Nerve CordDouble ventral with gangliaSingle dorsal without ganglia
BrainAbsent or above the pharynxDorsal to pharynx in the head
Nervous SystemSolidHollow
RespirationBody surface, gills, and tracheaGills or lungs
Dorsal Blood VesselBlood flows anteriorlyBlood flows posteriorly
Hepatic portal systemAbsentPresent
HemoglobinIn plasma or absentIn red blood corpuscles
Heart LocationDorsal, lateral, or absentVentrally placed
Blood vascular systemOpen, closed, or absentClosed and much developed
AnusOpen on the last segment or absentDifferentiated and open on the last segment
Pharyngeal gill-slitsAbsentPresent at some stages in life
Gut positionDorsal to the nerve cordVentral to the nerve cord
Limbs DerivationFrom the same segmentFrom several segments
Grade of organizationProtoplasmic or organ systemOrgan 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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