What type of organisms are identified as arthropods?

Arthropods are a diverse group of invertebrate organisms characterized primarily by their jointed legs and exoskeleton made of chitin. This group encompasses a variety of animals, including insects, arachnids (like spiders and ticks), crustaceans (such as crabs and lobsters), and myriapods (like centipedes and millipedes). The defining characteristics of arthropods, specifically their jointed limbs and segmented bodies, align perfectly with the description of external parasites that exhibit these features.

Insects and reptiles do not belong to the same taxonomic group; while insects are indeed arthropods, reptiles are vertebrates and do not share the characteristic jointed legs or exoskeletons of arthropods. Similarly, mammals and birds are warm-blooded vertebrates, which further separates them from arthropods. As for amphibians and fish, these groups are also vertebrates and lack the fundamental traits that define arthropods. Thus, identifying arthropods specifically as external parasites with jointed legs is accurate and highlights the unique features that categorize them within the animal kingdom.