Sponges are usually both male and female but rarely self-fertilize. Hermaphrodites with Internal Fertilization Sponges reproduce asexually and sexually.įigure 9: Budding in sponges Figure 10: Fission in sponges Sexual Reproduction ĬO2/O2 enter/exit through simple diffusion (movement of a substance across the cell membrane) Figure 8: Diffusion – the movement from high concentration to low concentration over a membrane D. Sponges function more like a colony of unicellular organisms. No respiratory or circulatory system! Each cell is responsible for it’s own food/waste etc. The host dies from this or becomes more susceptible to predation.The sponges bore into corals or shelled animals.Figure 6: Choanocytes Parasitic Sponges – Boring Sponges! Food enters the cell through phagocytosis ( Same as many unicellular organisms such as amoebas)Ĭhoanocytes ( Collar Cells ) – Cells surrounding the “collar” that strains food from the water.The spongocoel and canals are lined with choanocytes which have flagella (whip-like tails) which pull food inward.They pull water into the spongocoel (middle cavity of a sponge) through pores. Spicules hold pores open and keep sponge shape.Spicules are made of calcium carbonate (solid), silica, or spongin (a type of collagen – flexible and soft).Sponges are supported by a “skeleton” of spicules. Water is pulled into the spongocoel through pores and leaves out the osculum (top of spongeģ. First Multicellular animal – basic body plan is just four types of cells arranged around a series of pores/canals. All other animal groups evolved from sponge-like ancestorsįigure 1: Sponge Diversity A.Appeared ~700 Million years ago ( Oldest multicellular animals on Earth).Por i fera -> “ Pore” “ Bearing ” Latin Name means to bear pores.
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