Home Animal Kingdom Animal Kingdom

Animal Kingdom

by Ramneet Kaur



Basis of Classification:


animal kingdom


Salient features of different phyla in the Animal Kingdom:

PhylumDigestive systemRespiratory systemCirculatory systemMonoecious/




Distinctive features of different phyla in the Animal Kingdom:

Phylum Porifera:

  • Body cavity called Spongocoel present.
  • Water canal system present that helps in nutrition, respiration, excretion & reproduction.
  • The body has pores – mouth called Ostia & an outlet called Osculum.
  • Flagellated cells called Choanocytes present.
  • Skeleton made of Spicules & Spongin fibers.
  • Digestion is intracellular.

Phylum Coelenterata (Cnidaria):

  • Stinging cells called Cnidoblast / Nematocyst present for defense & offense.
  • Digestion is incomplete as mouth also acts as an anus.
  • Exhibit two basic body forms: Polyp & Medusa.
  • Metagenesis or alternation of sexual & asexual phases is seen. Both phases are diploid. E.g., Obelia.

Phylum Ctenophora:

  • Comb-like ciliary plates for swimming are seen.
  • Bioluminescence is seen.
  • Digestion is both extracellular & intracellular.

Phylum Platyhelminthes:

  • Flat body present.
  • Flame cells called as Solenocytes are meant for excretion & osmoregulation.
  • Self-fertilization occurs in Tapeworms.
  • Hook & suckers present in parasitic forms.
  • Planaria possess high regeneration capacity.

Phylum Aschelminthes (Nematode):

  • Syncytial epidermis.
  • Muscular pharynx present in the digestive system.

Phylum Annelida:

  • Metameric segmentation. The body is divided externally into rings.
  • Unjointed chitinous Setae present for locomotion, Nereis has Parapodia.
  • Haemoglobin in plasma.
  • Nephridia helps in excretion & osmoregulation.
  • Double ventral nerve cord consists of paired ganglia connected by lateral nerves.

Phylum Arthropoda:

  • Largest group with 900,000 species.
  • The thick exoskeleton is made of cuticle.
  • Jointed appendages.
  • Segmentation present.
  • Compound eyes present.
  • Excretory organs are Malphigian tubules.
  • The body cavity is Haemocoel (filled with blood).
  • Pheromones are secreted, that act as sex attractants.
  • Respiratory organs are book gills & trachea (book lungs).

Phylum Mollusca:

  • External skeleton of shell usually present.
  • The body has a distinct head, muscular foot & visceral hump.
  • Mantle covers the body.
  • The mouth has radula, a file-like rasping organ in the mouth.
  • Feather like gills is present in the mantle cavity that is respiratory & excretory.

Phylum Echinodermata:

  • Spines are present.
  • Water vascular system (ambulacral system), helps in locomotion, capture & transport of food and respiration.
  • Mesodermal endoskeleton of calcareous plates.
  • Shows bilateral symmetry in larvae & radial symmetry in the adult.

Phylum Hemichordata:

  • Worm-like animals.
  • Body divided into proboscis, collar & trunk.
  • Open circulatory system.
  • Respiration through gills.
  • The Excretory organ is proboscis gland.

Phylum Chordata:

  • Notochord present.
  • Dorsal hollow nerve cord.
  • Gill slits with limbs or fins present.
  • Closed circulatory system.
  • Ventral heart.
  • Post-anal tail present.


You may also like

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Lets make Biology simple

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More

Send this to a friend

Skip to toolbar