Sponges: Phylum Porifera PDF

1.PHYLUM SPONGES (PORIFERA) HUBKY GENERAL CHARACTERISTICS  belong to group Diblastica  Ectoderm  endoderm  primarily marine  Sessile – except larvae  simplest multicellular organisms  no tissues, only cellular-level organisation GENERAL CHARACTERISTICS heterotrophic organisms...

1.PHYLUM SPONGES (PORIFERA) HUBKY GENERAL CHARACTERISTICS  belong to group Diblastica  Ectoderm  endoderm  primarily marine  Sessile – except larvae  simplest multicellular organisms  no tissues, only cellular-level organisation GENERAL CHARACTERISTICS heterotrophic organisms Consumers – filter feeders Multicellular 2 basic types of cells Somatic Gametes GENERAL CHARACTERISTICS filter feeders – intracellular digestion no nervous system or sensory cells BODY STRUCTURE  4 cell tyes:  1. choanocyte s  2. epidermal cells  3. 1. Collar cells (choanocytes)  Interior of the sponge  Have flagella – create internal water current 2. Epidermal cells  external skin 3. Amoebocytes  In mesophyll (between collar and epidermal cells)  Digestion & transport of nutrients  Spicules  Gametes 4. Porocytes  Make pores of the sponge BODY TYPES: ASCONOID Simple tube with pores Single opening - osculum BODY TYPES: SYCONOID Larger body than asconoid Single osculum Thicker body wall BODY TYPES: LEUCONOID  The largest and the most complex  Masses of tissues penetrated by canals  multiple oscula REPRODUCTION  hermaphrodites  Reproduction  Asexual: through gemules created in mesophyll  sexual (usually cross-fertilisation) – release of sperms  high regeneration ability REPRESENTAT IVE Spongilla lacustris – hubka jazerná - lives in fresh waters REPRESENTATIV E  Venus flower basket (Euplectella aspergillum ) – venušin kôš  marine, up to 60 cm