The phylum Arthropoda is the most diverse phylum, which includes bees, spiders and flies. Arthropods have open circulatory systems and do not have blood, but instead a liquid called hemolymph. Also, their bodies are covered with an exoskeleton made up of a protein called chitin. The Arthropoda phylum is so vast that it is divided into subphylum.
Cheliceriforms examples are spiders, horseshoe crabs, ticks and scorpions. Their name is based off their claw-like feeding “mouths” called chelicerae. Cheliceriforms also lack an antennae, as well as lungs. Instead, gas exchange is carried out by book lungs. Arachnids make up the bulk of this subphylum. Spiders, an arachnid, spin webs for many reasons. Small spiders will spin webs for the wind to catch and take them to a new area. This behavior is called ballooning, while others will spin their prey into a web as an offering to potential mates. There is also evidence that shows that horseshoe crabs were one of the first organisms to make its way one land.
The Myriapod phylum is made up of centipedes and millipedes and all the Myriapods that exist today live on land. While centipedes and millipedes may look the same and are closely related, they have extremely different behavioral patterns. The centipede is carnivorous and poisonous. Millipedes eat decaying leaves, other plant matter and are non poisonous. The way to tell the difference is exceedingly straightforward. If the Myriapod in question, is flattened and has two legs per segment then it is a centipede. But if the Myriapod is round and has four legs per segment, it is a millipede.
Hexapods are insects. This subphylum has more species than all other forms of life combined. They are found everywhere in the world but are rare in marine environments. Dragonflies were one of the first insects to fly and flight are one of the best adaptations that hexapods have. Humans have relied heavily on hexapods throughout history. People use them to pollinate their crops and harvest honey. But they also compete with humans for food. In fact, insects claim about 75 percent of the crops in Africa. Hexapods are one of the only types of animals that humans, try as they might, have never been able to get rid of. Cockroaches can even survive a nuclear holocaust.
It might be astonishing to know that the majority of the seafood people eat is classified as a “bug”. Crustaceans are crabs, lobsters, shrimp and pill bugs. Amazingly, even though pill bugs have gills, they are still able to thrive on land, but only in semi-moist environments. Majority of crustaceans, however, live in marine and freshwater environments.