BIOL 2030 Lecture Notes - Lecture 5: Pinacoderm, Osculum, Mesohyl
25 Jan 2017
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Topic 1: outline phylum porifera sponges (chapter 6) Introduction: cell types, canal systems, reproduction, introduction. Sessile (attached to substrate and do not move around) multicellular animals with no organs. Filter feeders: system of canals through which water is pumped into the body and food particles collected. Canal systems: asconiods - simplest canal system; flagellated spongocoels, sponges are small and tube-shaped, water enters through tiny ostia into one large internal cavity called a spongocoel, and is expelled through one large osculum, mesohyl (gelatinous matrix, ostium. All sponges reproduce asexually and sexually: asexual reproduction in sponges, forms of asexual reproduction: fragmentation and/or budding. Step 3: sponge contracts back and leaves behind a piece = fragmentation, little piece grows into adult sponge; basically clone. Step 1 & 2: sponge looks the same. Step 3: little piece of sponge breaks off (budding), bud puts down roots and grows into adult sponge. Archeocytes cluster together inside the sponge and phagoctosie other cells to store nutrients.
