Arthropods are a very common animals on the earth. All arthropods are living things. There are more different species of arthropods on the earth than all the other animals put together. Arthropods are invertebrates, meaning they have no backbone. The characteristics of arthropods are:
- Jointed legs.
- Hard exoskeleton covering their body. This protects and supports them. Muscles are attached to it allowing for movement In terrestrial (land-living) arthropods, the exoskeleton stops their body from losing too much water and drying out
- The body of an arthropod is divided into multiple segments
There are many different kinds of arthropods. They are as follows:
Myriapods include the centipedes and milipedes. They are arthropods whose bodies are made of many different segments. They have many pairs of legs and a single pair of antennae.
Insects are the most recognisable group of arthropods in the world. Their bodies are divided clearly into a head, thorax and abdomen. The thorax is made up of three segmentds and the abdomen around 10-11. They have three pairs of legs (attached to the thorax) and most insects also have two pairs of wings (also attached to the thorax). They have a single pair of antennae.
Crustaceans include crabs, shrimps and woodlice. Their exoskeleton is especially strong as it contains calcium salts. They have many pairs of legs (crab has five pairs) and two pairs of antennae. Their body is made up of a combined head-thorax region known as a cephalothorax. An abdomen is present also. Each of these parts are made up of many segments.
Arachnids include spiders and scorpions. Like curstaceans their body is divided into a cephalothorax and abdomen. They have four pairs of legs and no antennae.