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The upcoming discussion will update you about the difference between vertebrates and invertebrates.
Difference # Vertebrates:
1. Vertebrates possess, at least in early life, a stiff-supporting rod, the notochord, which is placed in the mid-dorsal line and extends from end to end: it lies beneath the nerve cord but above the gut.
2. Pharynx is perforated on either side by a series of pharyngeal clefts or gill-slits. This is an efficient apparatus for carrying out respiration in vertebrates and persists throughout life in lower forms such as the fishes. Gill-slits appear in the embryo of reptiles, birds and mammals, although they never breathe by gills.
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3. The central nervous system of vertebrates is a hollow tube placed in the mid-dorsal line above the notochord. Its cavity is known as the neurocoel.
4. A living endoskeleton, composed of skull and vertebral column, is always found in vertebrates. This framework grows in size along with the growth of the animal.
5. The heart in vertebrates is located ventrally and beneath the gut.
6. in vertebrates blood circulates through a closed system of vessels—arteries, capillaries and veins.
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7. Hepatic-portal system, conveying the blood from the alimentary canal into the liver, is always present in vertebrates.
8. There are red blood corpuscles in vertebrates containing the respiratory pigment haemoglobin in their cytoplasm.
9. A true tail, consisting of a post-anal part of the body-axis, is usually found in vertebrates. This may persist throughout life or it may be an embryonic structure which is lost in the adult stage.
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10. Appendages or limbs in vertebrates are never more than two pairs.
11. Skin of vertebrates consists of two distinct layers, an outer epidermis overlying a thick dermis.
12. Eyes of vertebrates originate as outgrowths from the brain. Compound eyes are never found.
Difference # Invertebrates:
1. Notochord is never present in invertebrates.
2. Pharyngeal clefts are never formed in invertebrates, although some of the aquatic invertebrates may have gills for the purpose of breathing.
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3. In invertebrates the central nervous system is a solid cord placed in the mid-ventral line. There is go neurocoel.
4. Living endoskeleton, that is skull and vertebral column, is never found in invertebrates. There may be an armour of exoskeleton composed of non-living matter which never grows.
5. In invertebrates heart, when present, is located dorsally and above the gut.
6. Blood flowing through the arteries may pass freely into sinuses or open spaces within the body cavity in invertebrates.
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7. Such hepatic-portal system is never met with in invertebrates.
8. In invertebrates red blood corpuscles are not usually found. Haemoglobin, which is of rare occurrence, is found in solution in the blood-plasma.
9. True post-anal tail is not found in invertebrates. Anus is terminal and opens at the posterior end of the body.
10. Appendages, when present in invertebrates, are more than two pairs.
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11. Skin of invertebrates consists of only one layer.
12. Eyes develop from the skin in invertebrates and not from the brain. Compound eyes are often present.
