Vertebrates and invertebrates: differences and similarities

Image: Slideshare

The animal world is made up of a huge variety of species, all of them very different from each other. Even so, there are ways of grouping them into different classes, the most widely used being the one that divides the animal world into invertebrates and vertebrates. To know this division today in this lesson from a TEACHER we are going to talk about the differences and similarities of vertebrates and invertebrates.

To understand the differences and similarities between vertebrates and invertebrates, we must first define the two groups, to understand why this division exists.

Vertebrate animals

The vertebrates are all those animals that have spine or vertebral column. Vertebrates began as water animals, but they have evolved to be present in numerous habitats. The 5 classes of vertebrates that exist are the following:

• Mammals
• Birds
• Fishes
• Reptiles
• Amphibians

Invertebrate animals

On the other hand the invertebratesThey are animals that They have neither an articulated internal skeleton nor a vertebral column.

• Arthropods
• Mollusks
• Poriferous
• Cnidarians
• Echinoderms
• Flatworms
• Nematodes
• Annelids

Image: Pinterest

Once both groups have been defined, to continue this lesson on differences and similarities of vertebrates and invertebrates, we must talk about the differences that exist between the two.

Skeleton

The main difference between the two groups is that vertebrates have a vertebral column or spine, while invertebrates do not have any type of skeleton. This is the main difference, and the one that gives name to the two groups.

Quantity

Another difference is the number, the invertebrates being much more numerous. By some estimates there are almost two million species of invertebrates, while there are only about 60,000 species of vertebrates.

Size

The vertebrates are larger than invertebratesThe latter being largely small animals such as ants or wasps. Vertebrates are large animals such as elephants or whales.

Reproduction

Another difference can be found in reproduction, as vertebrates can be viviparous or oviparous, while invertebrates cannot be viviparous. The way invertebrates reproduce can be oviparous or asexual.

Metamorphosis

On the other hand, some invertebrates are capable of performing the metamorphosis, a process that allows them to change throughout their lives, and that vertebrates do not carry out. It is true that vertebrates grow in size throughout their lives, but they do not have such radical changes as those suffered by invertebrate animals that undergo metamorphosis. There is an exception to this, since amphibians if they reproduce, being the only vertebrates that do it.

Body

There are big differences regarding the body of the two groups. Vertebrates divide their bodies into head, trunk and limbs, while invertebrates have their bodies divided differently depending on the species. In addition, vertebrates have bilateral symmetry, which invertebrates do not have.

Blood

Vertebrates have closed blood circulation, while invertebrates can have both closed and open, although the vast majority have open blood circulation.

Image: Vertebrate animals

Once the differences that exist have been analyzed, we must talk about the similarities that vertebrates and invertebrates have, some of which have caused discussion when classifying the different species.

They are living beings and animals

The first similarity between vertebrates and invertebrates is that they are both living beings, that is, complex organisms that grow, reproduce and die. At the same time, both groups belong to the type of living beings called animals, a group of living beings that have the ability to move by themselves.

Sexual reproduction

Like the rest of living beings, vertebrates and invertebrates reproduce, the main form of reproduction being the sexual, unlike the vast majority of living beings. It is true that some invertebrates have asexual reproduction, but it is a small number.

Movement and sensitivity

Both groups are characterized by having motor and sensitive abilities, that is, they are capable of moving and feeling.

Notochord

Some vertebrates and invertebrates share possession of a flexible support rod called notochord. This notochord can change over time, evolving into bones. Depending on whether it evolves or not, the animal is either a vertebrate or an invertebrate.

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