[1] Porifera

• Made up of 5 - 10 thousand species
• Sponges are simple, asymmetric, sessile animals
• The sponge's body is built around a system of water canals
• Poriferan water flow:

  1. Water enters through tiny holes called the ostia
  2. Water flows through ostia into the spongocoel
  3. Water exits through a large hole called the osculum
• Sponges lack tissues, groups of specialized cells that perform a specific function
• Skeletal structural elements that make up the framework of body of sponge

  Spicules
• 3 sponge body types (in order of complexity):

  1. Asconoid
  2. No invaginations in body wall
  3. Syconoid
  4. Single spongocoel, many invaginations
  5. Leuconoid
  6. Multiple spongocoels
• Sponge group that exhibits symmetry

  Barrel sponges
• Collar cells or choanocytes are flagellated cells that circulate water and trap food
• Larval stage of most sponges

  Amphiblastula
• Sponge groups based on spicule composition:

  1. Calcarea - Calcium Carbonate
  2. Other 3 groups - Silica
• 4 sponge classes (CDHH):

  1. Calcarea
  2. Demospongiae
  3. Hexactinellida (Glass spicules)
  4. Homoscleromorpha
• Used in Japanese weddings as a gift to a couple

  Genus Euplectella, common name Venus Flower Basket
• Group that is cause of confusion phylogenetically

  Calcarea