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Phylum Porifera�“Pore Bearing”

Classes

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Calcareous          Glass              Demosponge

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Porifera Characteristics

Size and Symmetry - 1cm to 2m and most are completely asymmetrical

Tissues and Organs - No tissues or organs

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Porifera Characteristics

Recognition - Cells capable of recognizing each other

- separating cells through filter and cells will recombine into sponge

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Porifera Characteristics

Environment - Less than 2% in freshwater

Remaining 98% marine

Sessile - attach to sea bottom and

stay there for

whole life

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Porifera Structure

Diagram

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Porifera Structure

Porocytes - cells surrounding ostia

Ostia - tiny openings, pores, in body wall for water to enter

Oscula - larger

openings

in body wall

for water to exit

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Porifera Structure

Mesohyl - “middle stuff” gel-like substance that cells are suspended in

Choanocytes - flagellated cells with collar to draw water inside sponge

Amoebocytes - move through mesophyl to supply other cells with nutrients/wastes

Pinacocytes – epidermal-like cells that cover outer surface

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Porifera Structure

Diagram

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Porifera Diversity

Asconoid Syconoid Leuconoid

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Porifera Diversity

Class Hexactinellida – Glass Sponges

silica spicules

distinctive 6 point spicule (hexactine)

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Porifera Diversity

Class Demosponge –

silica spicules, porocytes, spongocytes and spongin fibers

distinctive 4-point spicule (tetraxon)

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Porifera Diversity

Class Carcaleous –

porocytes

loss of silica spicules and replaced with calcium carbonate spicules