Deep Dive into Marine Life

Sponges and Filter Feeders

• Classified in the phylum: Porifera, which means “pore bearing”
• Primarily a marine animal
• Few specialized structures
• Sessile: Live most of their adult life in one spot
• Benthic: Bottom dwelling organisms

Characteristics of Sponges

• Lack a nervous system
• Have musclelike cells that can close pores to prevent water from entering
• Defense mechanism involves closing pores to prevent water from entering

Sponge Feeding

• Animals must get food from the environment
• Sponges filter a ton of water to obtain an ounce of food
• Use collar cells (choanocytes) to filter food and water

Parts/Functions of the Sponge

• Inhalant pore (Ostia): Pores or openings that allow food & water to enter
• Collar cells (choanocytes): contain flagellum for filtering
• Pinocytes: Epithelium (skin) cells
• Osculum: Exit pore for filtered water
• Ambeoctes: Cells responsible for digestion
• Spicules: Provide structure for the sponge
• Spongocoel: Body cavity of the sponge