Types Of Invertebrates And Their Characteristics (Explained)

Animals classified as invertebrates lack the notochord-derived vertebral column and do not develop one. Except for the subphylum Vertebrata, these encompass all animals. As you read, you’ll get insight into the various Types Of Invertebrates And Their Characteristics.

Animals without backbones are known as invertebrates. Among the estimated 15–30 million species of animals, invertebrates make up more than 90% of the animal kingdom. There are invertebrates almost everywhere.

These have been discovered in the highest altitudes of the atmosphere, the canopies of the wettest rainforests, and the driest of deserts. They can also be found in the deepest oceans or the icy Antarctic.

Types Of Invertebrates And Their Characteristics 2

All these creatures are invertebrates, whether swatting away bothersome flies, uncovering worms, admiring the complexity of spider webs, or doing anything else. It would be nearly difficult to enumerate all the invertebrates. Numerous invertebrate species of all different sizes and forms assist us and are essential to our survival.

Types Of Invertebrates

These groupings include terrestrial invertebrates, many of which also include individuals that dwell in freshwater and marine settings.

  • Insects
  • Spiders
  • Worms
  • Slaters
  • Landhoppers
  • Centipedes
  • Millipedes
  • Silkworms

Freshwater and marine invertebrates have the following categories, some of which have land-dwelling members.

  • Sea urchins and sea stars
  • Corals and anemones
  • Slugs and snails
  • Sponges
  • Jellies and bluebottles
  • Lobsters, prawns, crayfish, and crabs

Characteristics Of Invertebrates

Invertebrates lack a backbone and an internal skeleton (endoskeleton) to provide support, which contributes to their soft bodies. Instead, many have support and defense mechanisms on the exterior (exoskeleton). Invertebrates also have cold blood, which means their body temperature fluctuates according to their environment because they cannot control it.

Characteristics Of Invertebrates

Invertebrates have a wide variety. They inhabit both marine and terrestrial environments, as well as other creatures as parasites. There are omnivorous invertebrates, predatory invertebrates, and herbivorous invertebrates (meat and plant eaters). Some invertebrate species even produce food inside their bodies by growing bacteria and cells. Some invertebrates stay in one position, whereas others fly, swim, float, crawl and burrow.

Example Of Invertebrate Animals


The most straightforward class of invertebrates, amoebas, are single-celled creatures. They are like most other cells in the human body in that they have a cell membrane, DNA, a nucleus, and organelles. The distinction is that amoebas have “false feet,” or pseudopodia, which they can use to move.


They employ pseudopodia to catch and consume food as well. In soil, where they control bacterial populations and recycle nutrients, beneficial amoebas can be found. Entameba histolytic, which causes diarrhea, is one of many ameba species that can be harmful.


Earthworms, also known as angleworms, are crucial to the environment because they aerate, transform, and mix organic matter into the soil through burrowing. These worms are one of more than 1,800 species that exist on land. In the soil, earthworms consume fragments of plants and animals.


In other species, portions of the organs are duplicated in each segment of the worm’s body, which is segmented. Earthworms are blind and deaf, but they can sense light and vibrations. Earthworms serve as a food source for birds and other creatures.


Because of the arms or “rays” that protrude from their bodies, starfish are also known as sea stars. While some starfish reside in the sea depths, others are found on the coast. The number of starfish species exceeds 1,600. The majority have five arms. However, one species has 24 arms. Starfish have tube feet that help them move by using hydraulic pressure.


Starfish use their arms to direct food particles from the water into their mouths and frequently eat snails, mussels, and clams. These organisms possess a rare capacity for arm loss and regeneration.


Decapods, like squids, have ten arms or tentacles. Unlike octopuses, which have eight limbs, they don’t have those. Four rows of suckers on each tentacle allow them to grab prey (often fish) and adhere to surfaces. Squids inhabit the ocean on the surface and deep within the water.


They can be anywhere from 3/4 of an inch to over 65 feet long. Some squids have light organs in their skin that enable them to change color so they can attract prey, conceal themselves, and communicate with other squids. Squid is consumed by humans, some fish, and sperm whales.


Except for Antarctica, all continents are home to spiders. They are not insects because of their eight legs (insects have six legs). According to experts, only approximately 39,000 of the estimated 170,000 species of spiders worldwide have been identified and named.


Spiders can be found both on land and in water. Species’ leg spans range from 0.02 inches to 10 inches. Most spiders have eight eyes, which can detect light and darkness. They are also highly vibration-sensitive, which is useful when the prey gets caught in their web.

While some spiders like to wrap up their live catch and store it for later, others prefer to poison their victim to kill it. Only liquids can be consumed by spiders, who puncture their prey with their bites and inject enzymes to break down the tissues so they can be sucked out.

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Final Verdict

I hope you understand all about the Types Of Invertebrates And Their Characteristics. The term “invertebrate” does not refer to a class of creatures that have a vertebral column nor do they ever develop one. It is a notochord-derived structure.

Creatures classified as invertebrates differ from vertebrate animals because the latter have bony or cartilaginous vertebral columns. Among all living things, invertebrates make up more than 90% of all organisms. Sea stars, earthworms, jellyfish, sea urchins, sponges, lobsters, crabs, insects, spiders, snails, clams, and squids are only a few examples of the vast group of organisms classified as invertebrates.

There is an essential invertebrate. Invertebrate animals play a significant role in transmitting parasitic illnesses or as parasites themselves. Additionally important as agricultural pests are these invertebrates.

The study of all Invertebrate animals, or animals without a backbone, is known as Invertebrate zoology (the structure found in fish, amphibians, reptiles, mammals, and birds). Carl Linnaeus made the distinction between the two classes of invertebrates.

Frequently Asked Questions

What are the six types of invertebrates?

The Invertebrates unit examines six categories of invertebrates: mollusks (including octopuses, snails, and clams), annelids (worms), poriferans (sponges), cnidarians (such as sea jellies and corals), echinoderms (such as sea urchins and sea stars), and arthropods (such as insects, spiders, and lobsters).

Are there ten groups of invertebrates?

Invertebrates have their phyla, numbering over 30. Porifera, cnidaria, Platyhelminthes, Nematoda, Mollusca, Annelida, Arthropoda, and Echinodermata, are essential invertebrate species you should be aware of.

What are the categories of invertebrates?

You may be highly familiar with the three primary groups: insects, arachnids, and crustaceans.

How do we classify invertebrates?

Vertebrate animals and invertebrate animals are the two broad categories into which all animals fall. Animals with a backbone are referred to as vertebrates. These creatures include humans, mammals, birds, and reptiles. On the other hand, invertebrates lack a backbone.

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