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Body Plan
Transport within the Body
No symmetry (asymmetrical) Consists of a perforated sac
Neither acoelomate, psuedocoelomate or coelomate.
  • Suspension-feeders (filter feeders) collect food particles from water passed through types of food-trapping equipment
  • insides are lined by flagellated choanaocytes (collar cells) which generate a water current while the collar cells trap food particles and ingest them by phagocytosis
Water is drawn through the pores into a central cavity (the spongocoel) and allows for substance transport internally via canals.
Gas Exchange
Method of Waste Disposal
Nervous System
Important Distinguishing Feature
(See transport) Sponges respirate by obtaining oxygen from the water transported through their body by diffusion.
Water and wastes flow out of the sponge through an opening called the osculum and via diffusion from the cells.
Sponges have no nerves or muscles, but individual cells can sense and react to changes in the environment and cells around pores and osculum can contract to close the openings
  • Sponges are hermaphrodites and can function as both male and female in sex by producing sperms and eggs.
  • gametes arise from chaonocytes/amaobocytes
  • eggs reside in mesohyl, and sperm are released into the spongocoel and are carried out of the sponge by the water current, allowing for cross-fertilization as sperm is drawn into neighboring individuals
  • fertilization occurs in mesohyl and zygotes develop into larvae covered with flagella which exit through the osculum
  • sponges can asexually reproduce by regenerating fragments broken off the parent sponge.
Sponges have existed for 580 million years and yet are the most simple of all animals in that they have no organs or brain. Their cell layers are loose federations of cells that are unspecialized (and thus are not tissues.)