ICZN PRINCIPLE

• Genus - is an assembly of related species which involved from a common ancestor and have certain common characters
• Family - a group of related genera with still less number of similarities as compared to genus and species.
• ORDER - the assemblage of families which exhibit a few similar characters.
• class - is a subdivision within a phylum made of one or more related orders
• PHYLUM- All these based on common features like presence of notochord and dorsal hollow neural system, are included in phylum Chordata.
• The highest category is called Kingdom
• Artificial classification - It is based on one or many characters that can be observed.
• Natural classification - It is based on the taxonomic characters like anatomical, biochemical, cytological, morphological, physiological characters.
• Phylogenetic classification - It is based on the genetic and phylogenetic relationship between taxonomic characters.
• International Code of Zoological Nomenclature (ICZN) - a set of rules and recommendations on the formal naming of animals.
• Aims of ICZN - to provide the maximum universality and continuity in the naming of all animals.
• SIX PRINCIPLES OF ICZN

  1. Principle of Binominal Nomenclature
  2. Principle of Coordination
  3. Principle of the First Reviser
  4. Principle of Homonymy
  5. Principle of Priority
  6. Principle of Typification
• Principle of Binominal Nomenclature - It states that the system of nomenclature for animals is binominal nomenclature. species have a name composed of two names, a "binomen"
• Principle of Priority - It states that the correct formal scientific name for an animal taxon, the name that is to be used, called the valid name, is the oldest available name that applies to it
• The Principle of the First Reviser deals with situations that cannot be resolved by priority, namely where there are two or more items that have the same date of publication (or the same year of publication when no details are known).
• Principle of Coordination - It states that the act of publishing a new Zoological name there by automatically and simultaneously establishes all the corresponding names in the relevant other ranks, with the same type.
• Principle of Homonymy - It states that any one name, in one particular spelling, may be used only once(within its group).This will be the first published name; any later name with the same spelling(a homonym)is barred from being used
• Principle of Typification - It states that any named taxon, in the family group, genus group or species group, has or should have a name-bearing type which allows the application of the name of the taxon to be objectively applied.