Arthropoda

Arthropoda:

  • It is the largest phylum of Animalia.
  • More than 2/3rd of all named species on earth are arthropods.
  • Excretion takes place by the malpighian tubules.

 

 

Characteristics-

Body Organisation:

    • Arthropods are triploblastic, coelomate animals. The organisms with bilateral symmetry.
    • Have an organ system level of organisation.
    • They possess a segmented body divided into distinct regions, such as head, thorax, and abdomen.
    • Arthropods have an exoskeleton made of chitin, providing protection and support.
    • They possess jointed appendages, allowing for a wide range of movements.
    • Sensory organs such as antennae, compound and simple eyes, statocysts or balancing organs are present.

Locomotion:

    • Arthropods exhibit diverse modes of locomotion.
    • Most arthropods use jointed appendages to walk, run, swim, or fly.
    • Appendages can be modified for specific functions, such as walking legs, swimming paddles, or wings.
    • Some arthropods, like spiders, can produce silk for web-building and movement.

Reproduction:

    • Arthropods reproduce sexually, with separate sexes (male and female) i.e. dioecious.
    • Fertilisation is usually internal, with the transfer of sperm from males to females.
    • Mostly are oviparous.
    • Some arthropods undergo indirect development, with distinct larval stages before reaching the adult form.
    • Others exhibit direct development, where the offspring resemble miniature adults.

Feeding Strategies:

    • Arthropods exhibit diverse feeding strategies depending on their ecological niche.
    • Many arthropods are herbivores, feeding on plants or plant materials.
    • Some are carnivores, preying on other animals.
    • Others are omnivores, consuming both plant and animal matter.
    • Arthropods possess specialised mouthparts, such as mandibles or sucking mouthparts, adapted for their specific feeding habits.

Examples:

    • Apis (Honey bee), Bombyx (Silkworm), Laccifer (Lac insect) are economically important insects.
    • Anopheles, Culex and Aedes (Mosquitoes) are vectors.
    • Locusta (Locust) is a Gregarious pest and Limulus (King crab) is a living fossil.
    • Prawn, scorpion, butterfly, etc. are some more examples of arthropods.