* They lack a backbone and an internal skeleton, but they often have a solid external structure to protect their body, and invertebrates make up more than 90% of all animals, and their length ranges from one millimeter to several meters, and includes various animals, including: sea stars  Sea urchins, sponges, jellyfish, insects, spiders, squids, etc.,

 * They are also considered food for humans, and they are also essential elements in the diet of birds, fish, and others, just as most invertebrates live in water, or spend part of their lives in water, although invertebrates do not have a backbone.  However, they do have little in common, as they display a wonderful variety of body shapes, mobility and feeding habits.

 Crab: It is a crustacean that has 10 legs, a short tail, and one pair of claws, and it has a structure made of calcium carbonate, and it can also live in different places of the world.  The butterfly (in English: Butterfly): It is a group of insects, and includes more than 15,000 species, the most famous of which is the Monarch butterfly. The butterfly is distinguished by its life cycle, which consists of four stages, namely the eggs, the larva, the cocoon, and then the adult butterfly.

 Jellyfish (English: Jellyfish):

 * Are marine animals;  However, some species that live in fresh water may also be found in waters near the coasts, and are considered carnivores, where they feed on plankton, crustaceans, and others.

 Mantis: It is an insect characterized by its long and folded limbs in a position that resembles prayer, as it uses these limbs to capture its prey, and is distinguished by its rapid predation, as it is also characterized by the ability to change its color to hide when chasing its prey.

 Ladybug: It is an insect that has an oval body that often contains black spots, the number of which varies from one species to another, and scientists have described 5,000 species of them so far.  Horseshoe crab: Horseshoe crab belongs to the group of chelicerata, and lives in shallow coastal waters that surround North America and Southeast Asia, and it also feeds on slugs, worms,

 * And other marine animals on the sea floor.  Octopus (English: Octopus): They are animals belonging to the group of cephalopods, and they are characterized by being very intelligent, and have good memory, and a complex nervous system, as they have a soft body, and have three hearts and eight legs.

 Jumping spiders: They are a group of spiders that have four pairs of eyes.  Three of them are fixed in a specific direction, and one can move, as it can see at an angle of 360 degrees, and it can jump on its prey.

 * Sponges (Porifera): They often live in salt water, and they pump water through their bodies to filter out food particles. They are also considered one of the oldest animals, and there are more than 5,000 species.  Cnidaria (in English: Cnidaria): is one of the ancient animals, which usually contains stinging claws, and this group is characterized by the presence of a central opening surrounded by claws through which waste is disposed of, and it also includes coral reefs, jellyfish, and anemones.  And the sea hornet, it is a family that contains 11,000 species.

 Echinoderms: are marine animals that have a hatch to eat, and they also have external skeletons, and this group includes sea cucumbers, sea urchins, and starfish.  Worms (in English: Worms): Also known as annelids, they are animals that have a distinct head and soft tube-shaped bodies, and this group contains earthworms and others, as there are approximately 20,000 species.

 * Molluscs (in English: Molluscs): They are soft living creatures that have a muscular foot that enables them to move and search for food, and they are usually found inside the shell, and this group contains octopus, squid, and others, which includes about 112,000 species.  Arthropods:

 It is the largest group of animals on Earth.  As they constitute more than 80% of living animals, as some live in water, some in the air, and some on land, and some arthropods have legs, and others have wings, and several types fall under this group, including crustaceans, spiders, and beetles  Butterflies, and others.

 * Ctenophora: it is a small family of marine invertebrates that swim weakly, and it is similar to a great extent in its shape, and it is characterized by 8 rows consisting of fringed plates arranged radially on the surface, as all carnivores are considered carnivores  It feeds on plankton through specialized adhesive cells, and is distinguished by its ability to regenerate lost parts of its body.