Invertebrate animals

Invertebrates: absence of backbone


There are two main groups in the animal kingdom: vertebrates and invertebrates. Both belong to the kingdom. AnimaliaHowever, body structure varies greatly from one group to the other.

Main characteristics of invertebrates

The invertebrate group includes 97% of all animal species except vertebrates (fish, reptiles, amphibians, birds and mammals).

A common feature of all invertebrates is the absence of the backbone. As an example, we can mention the sponges (although not always falling into this category, they are still part of this group).

In addition to the absence of backbone, there are other features common to these beings, such as:

- Multicellular formation (different groups of cells make up this organism).

- Absence of cell wall (as they are formed by animal cell).

- With the exception of sponges, they have tissues as a result of their cellular organization.

- Their reproduction is usually sexual (male and female gametes combine to form a new organism).

Generally speaking, we can say that the vast majority of invertebrates are capable of moving. However, sponges only perform this task when they are still very young and small. Lobsters and insects are able to move throughout their existence.

Food (general characteristics)

Unlike plants (which produce their own energy through photosynthesis), invertebrates need to extract the energy needed for their survival through other beings. For this, they feed on autotrophs (vegetables) and heterotrophs (animals).

Main phyla of invertebrate animals:

- Arthropods

- Mollusks

- Coelenterates

- Porifers

- Echinoderms

- Flatworms

- Annelids

Examples of invertebrate animals:

- Spiders

- Wraps

- Centipedes

- Octopuses

- Starfish

- Worms

- Insects (flies, mosquitoes, cockroaches, beetles, butterflies)

- Sea Sponges

- Seafood