title: Brain sponge
text: # Brain sponge
  
  The brain sponge (Isodictya elastica) is a species of marine demosponge in the family Isodictyidae. This sponge is known from the west coast of South Africa to Port Elizabeth. It is endemic to this region.
  
  ## Description
  
  The brain sponge may grow to 20 cm across. It has a smooth surface, covered with many scattered oscula. It may be beige to pink in colour and grows in two forms: one massive and convoluted, rather like a brain, and the other with narrowing fingers. Its texture is soft and compressible.
  
  ## Habitat
  
  This sponge lives on rocky reefs subtidally to 25m.
  
  