10 Facts About Arthropods

Arthropods are bilaterally symmetrical and their body possesses an external skeleton.

Arthropods have a wide range of chemical and mechanical sensors, mostly based on modifications of the many bristles known as setae that project through their cuticles.

Today, Arthropods contribute to the human food supply both directly as food, and more importantly, indirectly as pollinators of crops.

Arthropods have two body elements that are not part of this serially repeated pattern of segments, an ocular somite at the front, where the mouth and eyes originated, and a telson at the rear, behind the anus.

Arthropods, therefore, replace their exoskeletons by undergoing ecdysis, or shedding the old exoskeleton after growing a new one that is not yet hardened.

Arthropods are unprotected and nearly immobilized until the new cuticle has hardened, they are in danger both of being trapped in the old cuticle and of being attacked by predators.

Arthropods come from a lineage of animals that have a coelom, a membrane-lined cavity between the gut and the body wall that accommodates the internal organs.

Arthropods have open circulatory systems, although most have a few short, open-ended arteries.

Arthropods provide the earliest identifiable fossils of land animals, from about in the Late Silurian, and terrestrial tracks from about appear to have been made by arthropods.

Arthropods possessed attributes that were easy coopted for life on land; their existing jointed exoskeletons provided protection against desiccation, support against gravity and a means of locomotion that was not dependent on water.