Arthropods Facts

It is a herculean task to determine the exact number of species of arthropods inhabiting this planet, but studies suggest that the total number of these arthropods is greater than the number of all the other members of the kingdom Animalia put together. In fact, it is believed that the rainforests of Amazon alone house a million arthropod species, some of which are yet to be discovered. The range of interesting facts about the arthropods also contribute to their popularity among the scientists. One such fact is about the diversity in their size. While some arthropods measure less than a centimeter, others can grow up to attain a length of one foot.

Arthropods Characteristics
The members of Phylum Arthropoda, commonly referred to as the arthropods, are invertebrates typically characterized by an external skeleton (exoskeleton), a segmented body and six or more joint legs. With more than a million species in this family, this is by far the biggest group in the kingdom Animalia. Other than the general characteristics of arthropods mentioned above, there are a few more characteristic traits which are restricted to the particular species of this family. Even though we refer to spiders and scorpions as insects, it is technically incorrect, as these creatures belong to a totally different suborder of arthropods - the class Archinda. On the other hand, the insects belong to the class Hexapoda, yet another suborder of this genus. Overall there are five suborders of arthropods:

• Class Archinda (e.g. Spider and Scorpions)
• Class Crustacea (e.g. Crabs and Shrimps)
• Class Diplopoda (e.g. Millipedes)
• Class Chilopoda (e.g. Centipedes)
• Class Hexapoda (e.g. Butterflies and Moths)

Each of these suborders of arthropods have certain characteristics of their own which tends to differ them from the other suborders. For instance, the members of the Archinda suborder have a body which is segmented into two regions - the cephalothorax and the abdomen, while the members of the Hexapoda suborder boast of being the only invertebrates with the ability to fly. There are many more such facts about these arthropods, most of which, unfortunately, continue to be restricted to the zoology journals.

Interesting Facts about Arthropods
There are numerous interesting facts about the arthropods which one needs to know. Even though we know quite a lot about these creatures, we can't really boast of knowing everything. Given below is a compilation of some of the most interesting arthropods facts.

• Classified as a millipede, Pneumodesmus newmani, which inhabited the planet 428 million years ago, is considered to be the oldest known land animal on the Earth.
• Each of the segments of the body of arthropods is specially designed to facilitate particular functions, which include feeding, sensory perception, visceral functions etc.
• Among the entire lot of arthropods, the spiders have the most centralized nervous systems.
• With a body length of 16 inches, and an approximate weight of 9 lb, the Coconut crab is the largest arthropod in the world.
• In terms of the leg span, the Japanese spider crab is the largest arthropods with a leg span of 12 ft 6 inches when fully stretched.
• While internal fertilization is common in the terrestrial as well as the aquatic arthropods, some aquatic arthropod species do undergo external fertilization.
• Even though most of the arthropod species lay eggs, scorpion tend to give birth to its young ones when the eggs hatch inside the females body.
• The Amazonian giant centipede is the largest centipede in the world, which can grow to a length of 30 centimeter.
• The giant African millipede is the largest of the millipede in the world, which can grow to an average length of 28 centimeter.
• Arthropods are subjected to a biological process referred to as metamorphosis, wherein, their body form and physiology goes through a radical transformation from egg stage to larva, pupa, and adult state.

These and other such facts make this genus one of the most amazing attributes of the Earth's ecosystem. As we mentioned earlier, several species of arthropods are waiting to be discovered in various biomes of the world, which means that our chances of coming across a range of new facts about the members of this genus are not at all rare.