16 Difference Between Chordates And Non-chordates (With Examples)

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The name chordate is derived from the word notochord. A notochord is a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and in adulthood of some adult chordate species. The notochord is located between the digestive tube and the nerve chord, it act as the primary axial support of the body throughout the animal’s entire life. From the description therefore, chordates are animals with a backbone or notochord while non-chordates are animals without a backbone or notochord. In this article, find more information on the difference between chordates and non-chordates.

The Key Differences

  1. The body of chordates is bilaterally symmetrical with some level of organ-system organization. On the other hand, non-chordate’s body can be cylindrical, radial or bi-radial in symmetry.
  2. Chordates can be cold-blooded or warm-blooded whereas non-chordates are only cold-blooded.
  3. Chordates have a notochord at some stage in their life whereas a notochord is not present at any stage in the life of a non-chordate. A notochord is a flexible skeletal rod that is made up of cartilage. It runs between an animal’s digestive tube and its nerve cord and provide support for the body. In some species of phylum chordate, the notched is present only in the larval tail and in some; it is present throughout their life from head to tail region.
  4. Respiration in non-chordates takes place through body surface, gills or trachea while respiration in chordates is through gills or lungs.
  5. The central nervous system of chordates is hollow and dorsal while non-chordates, their central nervous system is solid and either ventral or lateral within the body.
  6. Chordates have a post-anal-tail at some stage in their life while non-chordates do not at all have a post-anal-tail in their stages of life. A post-anal-tail is a posterior elongation of the body that helps propel aquatic animals in water provides balance and is used by some terrestrial vertebrates to attract mates and signal when danger is near.
  7. Chordates have a clearly differentiated anus that opens before the last segment while in non-chordates the anus is either absent or opens at the last segment.
  8. The pharyngeal gill slits occur in the adult or embryonic stages of chordates. On the contrary, pharyngeal gill slits do not occur in non-chordates. In invertebrates, the pharyngeal slit is used in feeding as a filter while in vertebrate fish; it develops into gill arches, the function of which is to support the gills.
  9. The endoskeleton and exoskeleton are present in chordates whereas in non-chordates only exoskeleton is present.
  10.  Chordates feature a closed circulatory system while in non-chordates the body features an open type of circulatory system and front side central nervous system.
  11. The chordates’ heart is ventral whereas in non-chordates the heart is usually dorsal if present.
  12. Chordates are referred to as true coelomate, while non-chordates can be acoelomate, pseudocoelomate or truly coelomate.
  13. The brain of chordates is dorsal to pharynx in the head whereas, non-chordates, the brain is absent or above pharynx if present.
  14. Chordates may either have red blood cells or not, in case the red blood cells are present, their content will have hemoglobin. Non-chordates on the other hand, do not have red blood cells and in case, hemoglobin and other respiratory pigments are present, they will be found suspended in the blood plasma.
  15. Examples of chordates include: Hemichordata, cyclostomata, Aves, Reptiles, Amphibia and mammals. On the other hand, examples of non-chordates include protozoa, Arthropods, annelids etc.
  16. Reproduction in chordates is predominantly sexual whereas reproduction in non-chordates is predominantly asexual. 

Also Read: Difference Between Vertebrates And Invertebrates

Differences Between Chordates And Non-Chordates In Tabular Form

THE BASIS OF COMPARISON CHORDATE NON-CHORDATE
Body Shape The body of chordates is bilaterally symmetrical with some level of organ-system organization. Non-chordate’s body can be cylindrical, radial or bi-radial in symmetry.
Temperature Regulation Chordates can be cold-blooded or warm-blooded. Non-chordates are only cold-blooded.
Notochord Chordates have a notochord at some stage in their life. a notochord is not present at any stage in the life of a non-chordate.
Respiration Respiration in chordates is through gills or lungs.   Respiration in non-chordates takes place through body surface, gills or trachea.
The Central Nervous System The central nervous system of chordates is hollow and dorsal. The central nervous system of non-chordates is solid and either ventral or lateral within the body.  
Post-anal-tail Chordates have a post-anal-tail at some stage in their life. Non-chordates do not at all have a post-anal-tail in their stages of life.
Anus Differentiation Chordates have a clearly differentiated anus that opens before the last segment. In non-chordates the anus is either absent or opens at the last segment.  
The Pharyngeal Gill Slits The pharyngeal gill slits occur in the adult or embryonic stages of chordates. Pharyngeal gill slits do not occur in non-chordates.
Endoskeleton and Exoskeleton The endoskeleton and exoskeleton are present in chordates. Non-chordates only exoskeleton is present.  
Circulatory System Chordates feature a closed circulatory system.   Non-chordates the body features an open type of circulatory system and front side central nervous system.
Heart The chordates’ heart is ventral.   Non-chordates the heart is usually dorsal if present.
Description Chordates are referred to as true coelomate. Non-chordates can be acoelomate, pseudocoelomate or truly coelomate.  
The Brain The brain of chordates is dorsal to pharynx in the head. Non-chordates, the brain is absent or above pharynx if present.  
Red Blood Cells Component Chordates may either have red blood cells or not, in case the red blood cells are present, their content will have hemoglobin. Non-chordates do not have red blood cells and in case, hemoglobin and other respiratory pigments are present, they will be found suspended in the blood plasma.  
Examples Examples of chordates include: Hemichordata, cyclostomata, Aves, Reptiles, Amphibia and mammals. Examples of non-chordates include protozoa, Arthropods, annelids etc.  
Reproduction Reproduction in chordates is predominantly sexual. Reproduction in non-chordates is predominantly asexual.   

What is the main difference between Chordates and Non-Chordates

Chordates have a notochord at some stage in their life whereas a notochord is not present at any stage in the life of a non-chordate.