GENERAL CHARACTERISTICS OF PORIFERA

L.,Porus=pore; fer=bearing

Mostly marine animals, but some fresh water forms also exist.
They are sessile, living attached to rocks, corals, and other hard surfaces.
Diploblastic animals. Mesoglea is present between ectoderm and endoderm.
Body is asymmetrical. But a few have radial body symmetry also e.g., leucosolenia.
Body is plant like and fixed to some type of substratum. Body surface is perforated by numerous pores, the ostia. Coelom absent.
Cellular grade of body organization.

Sponges exhibit canal system through which water and food passes inwards and waste products comes outwards.
Respiration occurs directly i.e., through normal body surface.
Nervous system is absent.
Digestion is intracellular.
Asexual reproduction is by budding. Sexual reproduction takes place by discharge of egg and sperm in the paragastric cavity.
Fertilization is internal. Cross fertilization is the rule.
Hermaphrodite or Monoecious animals.