Canal system of phylum porifera

Criterion	Ascon	Sycon	Leucon
Complexity	Simplest	Intermediate	Most complex
Spongocoel	Present	Present	Absent
Radial Canals	Absent	Present	Absent
Surface Area	Limited	Increased	Extensive
Filtration	Limited	Enhanced	Highly efficient
Choanocytes	Lining the spongocoel	Lining radial canals	Lining chambers and canals
Water Flow	Direct	Radial	Complex, multidirectional
Osculum	Present	Present	Present
Examples	Small, simple sponges e.g Leucosolenia	Medium sized sponges e.g Scypha (bag sponge)	Larger, more complex sponges e.g Clathrina