Vertebrate and invertebrate animals: characteristics, examples and differences

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The animal kingdom is a large group belonging to the eukaria domain, whose member animals present a unique and differentiating characteristic among them, such as the presence or absence of an internal skeleton. However, something in common and that encompasses them in the same edge called Chordata (chordates) is the presence of the notochord, a structure that serves as a support and that in vertebrates becomes the vertebral column, in addition to other characteristics that we will talk about in this article.

If you want to know more about the characteristics of the vertebrate and invertebrate animals, examples and their differences and similarities, continue reading this article by Ecologist Verde.

Characteristics of vertebrate animals

Next, we are going to mention, as a summary, the main characteristics of vertebrate animals:

  • As a starting point, we can say that vertebrate animals are those that present internal skeleton articulated and formed by calcified or cartilaginous bones but, although the concept "vertebrate" refers to the vertebral column, the truth is that this characteristic has evolved a lot since the first animals considered vertebrates, since they did not have a vertebral column. So why are they considered vertebrates? Well, the original term refers to the fact of having a skull.
  • The first vertebrates in history also did not have jaws, which are linked to the skull, an element also characteristic of this group of animals and their appearance, as justified by many authors, is that of a change in feeding from filtration to predation. Considering the phylogenetic evolution of vertebrates, the first considered are a group of jawless fish dating back 550 million years.
  • Next in the tree of evolution, are the cartilaginous fish (such as sharks or rays), which lack ossification in their bones and is also a very old group but not as numerous as the bony fish (like salmon or mackerel).
  • Later, about 365 million years ago, amphibians and from then on, reptiles and birds and finally, the mammalsThese last two groups are characteristic for internally regulating their body temperature (they are endotherms).
  • In short, all vertebrate animals have in common the possession of an internal bony or cartilaginous skeleton, bilateral symmetry, a skull and a notochord in the form of a vertebral column.

Examples of vertebrate animals

Next, we expose a series of examples of the classification of vertebrate animals, some of which you probably know:

  • Fish: without jaws (agnate), such as lampreys or mixines, or with jaws (gnathostomes), such as sharks or clown fish.
  • Amphibians: such as frogs, salamanders, toads or newts.
  • Reptiles: lizards, snakes, crocodiles, and turtles.
  • Birds: such as ostrich, pigeons, raptors, penguins …
  • Mammals: like kangaroos, bats, or humans.

We recommend you learn more details with this other article on Vertebrate animals: classification, characteristics and examples.

Characteristics of invertebrate animals

Now we focus on mentioning the main characteristics of invertebrate animals:

  • They have no backbone or internal skeleton articulated, although yes they have notochord.
  • However, it is possible that some of the animals in this group have exoskeleton, as in arthropods.
  • On the other hand, it is a very extensive and diverse group of animals that also have in common that they are ectotherms, that is, they cannot maintain a constant body temperature.
  • Another characteristic is that they can present radiated symmetry, that is, the animal's body cannot be divided into two equal parts.
  • The origin of invertebrates is difficult to determine, since there is no clear evidence of the first to inhabit the Earth because they were soft-bodied and small-bodied and, therefore, no direct fossil evidence remained.

Discover +20 curiosities of invertebrate animals.

Examples of invertebrate animals

In this section we present the classification of invertebrate animals with some of its more general characteristics.

  • Arthropods: very diverse group that represents 80% of animal species and includes insects, spiders, or aquatic species within crustaceans or insect larvae.
  • Cnidarians: it is the group of jellyfish, anemones and corals.
  • Flatworms: Flatworms are the most primitive group of invertebrate animals and are known as the flattened worms.
  • Annelids: more commonly known as worms, which include leeches as well and owe their name to presenting ring-shaped segments throughout the entire body.
  • Mollusks: they are invertebrates whose main characteristic is the presence of a shell that protects its soft body. Include clams, oysters, octopus, or snails.
  • Echinoderms: it is a group of marine animals that has spines on the body and includes starfish, urchins, brittle stars, holothurians and crinoids.
  • Poriferous: better known as sea sponges, they are a phylum of aquatic animals that present pores through which water flows and thanks to which it filters nutrients.

Here you can read more about invertebrate animals: examples and characteristics.

Differences between vertebrate and invertebrate animals

We can conclude, therefore, that there are clear differences between vertebrate and invertebrate animals.

  • Vertebrate animals have internal skeleton bone or cartilaginous and invertebrate animals can present exoskeleton with which they protect the internal organs.
  • There are ectothermic vertebrates and endotherms and invertebrates are usually ectotherms.
  • Vertebrates tend to have a larger body size than invertebrates.
  • Vertebrate animals usually have sexual reproduction with the exception of some viviparous fish. However, invertebrate fish are mostly oviparous.

Similarities between vertebrate and invertebrate animals

Despite the great differences between the two groups, it is also possible to find similarities between them.

  • In general, they are living beings from the domain of eukaryotes, belonging to the animal kingdom or Animalia and, therefore, reproduce, develop and die.
  • They are also capable of moving autonomously, as well as having the ability to capture information from the outside through external or internal sensory organs.
  • They are also heterotrophic organisms (unable to make their own organic matter) and multicellular.
  • More specifically, vertebrates and invertebrates have the presence of the notochordThey have a digestive system with a mouth and anus and a closed circulatory system and segmented muscles.

If you want to read more articles similar to Vertebrate and invertebrate animals: characteristics, examples and differences, we recommend that you enter our Biology category.

  • Padilla, F., Cuesta. A., 2003, Applied Zoology, Editions Díaz de Santos.
  • Biology-Geology, General characteristics of invertebrates:
  • Ck-12, Evolution of Vertebrates:
  • Hypertexts of the Biology Area, Celomados II: Chordates:
  • Animal Expert, Bony fish: examples and characteristics:
  • Animal Expert, Classification of vertebrate animals:
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