All those animal species that do not have bones are classified as invertebrates, even so certain varieties have cartilaginous structures that give rigidity to their body. Invertebrates populate almost all habitats on the planet and many of their species are unknown, so much so that others do not appear to be animals given their physical appearance. Find out much more about the Boneless Animals below.
animals without bones
Invertebrates are classified as all those species of animals that do not have a backbone or an articulated skeleton. They represent more than 95% of all the varieties that have been registered to date. Some of these invertebrate animals are usually confused with vertebrate animals because they have a cartilaginous skeleton. Although this last skeleton provides rigidity to the body, it is not classified as bone. Among the animals that do not have bones we find the octopus, the crayfish, the sea anemones and the centipede.
Features
Invertebrate animals generally have the following common characteristics:
- They are tiny species.
- They do not have an articulated internal skeleton (of a bony or cartilaginous nature). Certain species do have them, such as arthropods, however it is an external skeleton which is usually called an exoskeleton.
- Most of them are covered by shells, shells or solid coverings.
Examples of Animals Without Bones
Both the quantity and the different types of invertebrates are usually difficult to determine, but they make up a large group that is generally separated between those that have body protection and those that do not. In the first group are the arthropods (with articulated legs and sectioned body, like most insects, arachnids and crustaceans), molluscs and echinoderms, while on the other hand there are worms (with a soft and long body) , the coelenterates and the poriferous (similar to marine plants). Here are some examples:
Octopus
The octopus is a creature that belongs to the group of mollusks. It has a large size, ranging from 15 centimeters to 3 meters in length. Their eating habits are omnivorous; that is, it usually feeds on both animals and plants.
Squid
The squid, like the octopus, is a mollusk that lives in the sea, and they are invertebrate beings with a soft body without a cover or covered by some kind of shell. The squid, also called teutido, can measure from 10 centimeters to 18 meters. These latter specimens are rarely seen and are often called giant squid.
snail
The snail is a mollusk that carries a spiral shell on its back, which serves as protection against any threat. There are land and sea specimens. Land snails can measure up to 20 centimeters in length, while the largest marine snails can measure up to 91 centimeters.
Medusa
Jellyfish are creatures whose age dates back more than 500 million years. Their bodies possess unique and diverse characteristics. They are animals that can be translucent or transparent, presenting different colors and sizes, and are among the creatures with the highest life expectancy.
Centipede
These animals are classified within the class of chilopoda and have different presentations. They can reach lengths from one centimeter to about 30. They can exhibit different colors and some have the ability to secrete poison.
Worm
The worm has a long, reddish body that can reach a length of a few centimeters to a maximum of 35. The worm usually feeds underground at night, and its activity is considered to benefit the development of certain plants.
Crab
There are more than 4.000 varieties of crabs, which usually have very different sizes and colors. All of its species show a very rigid body; however, the crab is classified as an invertebrate since its skeleton is completely cartilaginous.
planaria
This creature can be considered both sea and land. The planaria has an elongated, wide and flat body; hence its name. This animal has tentacles and a size that can vary from one to 6 centimeters.
Sea urchins
Also known as echinoids, they are balloon-like animals that have mobile spikes, which can inoculate poison. These creatures usually have different sizes, appearances and colors. Despite remaining motionless, certain varieties are predators.
sea anemones
Sea anemones are often called this because of their resemblance to the anemone flower. They are marine creatures with a cylindrical body and tentacles at the top. Numerous fish use anemones and their tentacles for storage and protection.
Tapeworm
This is a parasite, which is also given the name of tapeworm, which usually causes various diseases in other animals such as cats, dogs or humans, regularly at the stomach or intestinal level.
Mosquito
A well-known legend tells that the mosquito has bones. Nothing more uncertain, since this insect manages to maintain its structure thanks to the fact that it has a substance that gives it flexibility and that does not allow water to pass through its body.
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