PHYRUM ARTROPODA
Arthopoda is a phylum within Animalia kingdom. They are most diverse of all phyla. All arthropods have bodies covered with a tough exoskeleton which consists of layers of chitin and proteins. They are bilaterally symmetrical. Arthropod body is segmented but also divided into head, thorax and abdomen. Head and thorax can be joined to form a cephalothorax
Arthropods have five main groups: arachnids, centipedes and millipedes, horseshoe crabs, and insects. The phylum arthropoda is most successful in terms of geographical distribution, diversity and in numbers.
Insects are most successful within the phylum arthropoda as they are most diverse and abundant group of organisms on earth. Insects exist in almost all habitats on earth. Their biological success is by numbers. They have many adaptations which make them successful.
The ability of insects to fly is important as they can exploit more resources in many locations. Flight enables them to escape from predators. Their population is able to spread into new habitats and locate new resources.
Insects are small in size which gives them advantage as minimal resources are required for their survival and reproduction. Because of small size, insects can hide from predators in cracks. Insects have a supporting exoskeleton. Exoskeleton gives support and shape to body’s soft tissues. Exoskeleton provides protection against injury, attack or loss of fluids from body in fresh water and arid environment.
Another adaptation seen in insects is metamorphosis. Insects have several developmental stages during their life cycle. The changes may be behavioral alteration, physical or biochemical that improves dispersal, survival and reproduction of species. The most common form of metamorphosis in insects is complete metamorphosis. It involves egg hatching into larva which develops into pupa then finally the adult