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

Cold-blooded animals
Lack notochord
Breathe through skin surfaces and develop gills
Have bi-radial body symmetry
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

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

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Main Differences between Vertebrates and Invertebrates

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

Similarities between Invertebrates and Vertebrates

Both belong to kingdom Animalia
Both have gills
Both have a nervous system
Both have heart
Both show bilateral symmetry
Both exhibit movement
Both can adapt to the environment
Both live on land and in water
Both can reproduce and respire

Summary

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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