Canal system in sponges

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 Canal system in sponges 

There are three different types of canal system found in sponges are as follows :-
1.Ascon type:- eg. Leucosolenia
  • Simplest type of canal system
  • Spongocoel is lined by flagellated caller says or chanocytes
  • Ostia open into is Spongocoel  which is a single , large , spacious cavity in the sponge body
  • Spongocoel open to outside through a narrow circular opening called the osculum  located at the distal free end
  • Flow of water is slow because the large is Spongocoel  contains much water that cannot be pushed out readily  through a single osculum
  • Ingressing water - Ostia - spongocoel - Osculum - water outside

2.Sycon type :- eg - scypha, Grantia
  • In more complex Sycon type  incurrent canals are irregular branching and anastomosing,forming large sub dermal spaces.
  • There are two types of canals are found in as sycon type in current and radial Alernate with each other
  • Incurrent pores (dermal Ostia) found on outer surface of the surface of the body open into prosopyles . Prosopyles  open into a radial canals apopyles.Apopyles open into Spongocoel .water from spongocoel  leaves outside through osculum.
  • Ingressing water - dermal Ostia - incurrent channels - prosopyles - radial canals - apostles - spongocoel - osculum - outside

3.Leucon Type :- e.g- spongilla
  • The most complex canal system is Lee Kun type
  • Further folding of the body wall
  • The engrossing water comes into incurrent canals through dermal Ostia  passes through prosopyles into flagellated chambers communicate with ex-current canal through Apopyles  exurrent canals are  developed due to Spongocoel 
  • Ingressing water - Dermal Ostia - Incurrent canal - prosopyles - Flagellated chamber - Apopyles - Excurrent canals - osculum - Outside 

4.Rhagon Type:-
  • Canal system of rhagon larva does not occur in any adult response
  • Spongocoel  is surrounded by a flagellated chambers opening into through a very wide apopyles
  • Ingressing water - Dermal ostia - Flagellated chambers - Apopyles - Spongocoel - Osculum- outside


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