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Phylum Porifera. General Characteristics. SPONGES ! Simplest of all animals _________________ No true tissues or organs _________________________ Marine and Freshwater Saltwater are colorful Freshwater are dull green color. General Characteristics Cont. Sponges are sessile as adults
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General Characteristics • SPONGES! • Simplest of all animals • _________________ • No true tissues or organs • _________________________ • Marine and Freshwater • Saltwater are colorful • Freshwater are dull green color
General Characteristics Cont. • Sponges are sessile as adults • Free swimming larval stage called dipleurula • Porifera means pore-bearing • Water enters through pores bringing in food and oxygen • ____________________________ • Osculum- large opening at the top where excess water leaves
Water Flow Through the Sponge WATER OUT WATER IN Osculum
3 Basic Cell Types • _______________ • Mesenchyme Cells • Choanocytes
3 Basic Cell Types • 1. Pinacocytes- flat cells that line the outer surface of the sponge. • May be slightly contractile • ____________: a specialized type of pinacocyte; are tube-like in shape; contractile; and can regulate water circulation.
2. Mesenchyme Cells- move around in the mesohyl layer; are specialized for reproduction, secreting the skeleton, transporting/storing food. • ____________: jelly-like layer just underneath the pinacocyte layer.
3. Choanocytes- flagellated cells that line the inner chamber of the sponge; called collar cells. • Flagellum: flagella spins to create water currents to pull in water and food • Collar: __________________________ (plankton) from the water
Choanocyte Choanocyte
__________________________ • Consists of either one or all of the following: • Spicule: microscopic needle-like spikes that are made of Calcium carbonate (CaCO3) or silica (glass). • Spongin: a fibrous protein made of collagen
Sponge Skeletons Silica Spicules Limestone Spicules SPONGIN
Sponge Body Types • 3 Kinds- • Ascon • __________ • Leucon
Ascon • ____________________ • Are vase-like • Least common type of sponge
________________ • Sponge wall is folded into canals • Choanocytes line the radial canals to move water
Leucon • Have an extensively branched canal system. • ___________________________ • Multiple ostia for water to exit • Increased surface area means more water can move through sponge
Reproduction • Sexual Reproduction- sponges are monoecious (male and female in the same body) • Release sperm and eggs into the water from the Osculum • Cross-Fertilization takes place in the ocean • _____________________________
Reproduction Sponge Releasing Eggs & Sperm
Reproduction Cont’ • Sponges can regenerate (regrow) lost body parts through mitotic cell division (asexual) • Sponges also reproduce asexually by ________________
Reproduction Cont’d • Asexual Reproduction- involves the formation of gemmules • ______________: resistant capsules that sponges release to survive unfavorable conditions. • When conditions become favorable, the gemmules sprout into sponges. gemmule
_____________________ • Phylum Porifera • 3 Classes • Class Calcarea • Class Hexactinellida • Class Demospongiae
Class Calcarea • Spicules made of Calcium Carbonate • Can have all three body forms • __________________ • Ex. Grantia
Class Hexactinellida • ___________________________ • Can have syncon or leucon body forms • Often fused into an intricate lattice • Glass sponges
Class Demospongiae • Spicules made of silica, spongin, or both. • ____________________ • Ex: common bath sponge