Phylum Porifera: [Pori- Pores/Holes, Fera-To Bear]

PHYLUM PORIFERA: [PORI- PORES/ HOLES, FERA- TO BEAR]

Animals that belong to group porifera have holes all over their body. They are commonly known as sponges.
Habitat: They are aquatic animals which are found in marine water. Exceptions may be there.
Habit: They are sessile [stalk-less or resting on the base without foot], sedentary, i.e., they remain attached to the substratum throughout their life and non-motile.
Symmetry: Their body is asymmetrical or radially symmetrical. Sponges may be vase- like, rounded, sac-like or branched.
Body cavity: They are acoelomate, i.e., true cavity is absent but a hollow cavity is present inside their body known as spoongocoel.
Body differentiation: They have cellular level of organization or minimal division and differentiation into tissues is observed.
Germ layer: They do not show tissue/ organ formation so they are neither diploblastic nor triploblastic. The cells are loosely held together with a gelatinous cementing material.

Body organization:

Body is perforated with pores present all over the body. These pores are known as ostia [ostium] that open into a canal system.
The canal system is required for the circulation of water that helps in transportation of food and oxygen. The pore that brings inside the water stream is known as osculum.
Skeleton: They have the external hard covering known as skeleton which is made up of calcareous or siliceous spicules or collagen fibres or both.
Life processes: digestion is intracellular, respiration and excretion occurs through diffusion and reproduction may be asexual [Budding] or sexual.

Examples: