Kingdom Animalia


Tejinder Kaur, Academic Content Writer at Edumarz

Phylum Annelida:

  • The word annelida is derived from Greek work “annulus” meaning ring because there body is divided into segments.

  • They display characteristic metameric segments i.e. their body is divided into continuous serial segments.

  • Habitat is marine, freshwater as well as terrestrial.

  • The body is well differentiated into head and tail.

  • The body is bilaterally symmetrical.

  • Have a triple layer of cells hence called triploblastic.

  • Example: Earthworm , leech

Phylum Arthropoda

  • The word arthropoda means jointed legs i.e. the organisms of this phylum have jointed limbs.

  • This is the largest phylum of the animal kingdom i.e.  displays the largest diversity.

  • The animals of this phylum have characteristic jointed appendages, hard exoskeleton and a segmented body.

  • They have well developed organs and organ systems.

  • The circulatory system is open i.e. blood flows directly in the body cavity, no proper blood vessels present.

  • Example: Spiders, butterflies

Phylum Mollusca

  • The animals of this kingdom have a soft body.

  • The body is divided into head, trunk and foot.

  • The body is triploblastic and bilaterally symmetrical.

  • The organ and organ system is well developed.

  • The circulatory system is open.

  • No limbs seen.

  • Example: Snail, Octopus

Phylum Echinodermata

  • The word Echinodermata is made up of the Greek word “echinos” meaning spines i.e.  the animals of this phylum have bodies covered by spines.

  • The habitat is marine.

  • The animals have a well developed characteristic “water vascular system” which helps in major metabolic activities.

  • Have well developed coelom hence called Coelomates.

  • Have a skeleton made up of Calcium Carbonate.

  • The symmetry is radial i.e. the body can be divided into two halves by more than one plane passing through the centre.

  • Example: Starfish, Star Urchins

Phylum Hemichordata

  • The body is divided into head, trunk and proboscis.

  • Animals of this phylum have single layered epidermis.

  • Well developed organ system is present.

  • Have an open circulatory system.

  • Gills are developed for respiration.

  • The fertilization is external i.e. the germ cells are released externally for fusion.

  • No larval stage is a stage so the development is direct.

  • Example: Balanoglossus

Phylum Chordata

  • Well developed characteristic notochord is present.

  • The animals have bilateral symmetry, are triploblastic and have organ system level of classification.

  • The circulatory system is closed i.e. blood flows in blood vessels.

  • The phylum is subdivided into three subphyla:

  1. Urochordata

  2. Cephalochordata

  3. Vertebrata

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