Choanocyte

Mesohyl

Pinacocyte

Choanocyte

Lophocyte

Porocyte

Oocyte

Archeocyte

Sclerocyte

Spicule

Water flow

Main cell types of Porifera^[1]

Choanocytes (also known as "collar cells") are cells that line the interior of asconoid, syconoid and leuconoid body types of sponges that contain a central flagellum, or cilium, surrounded by a collar of microvilli which are connected by a thin membrane.

They make up the choanoderm, a type of cell layer found in sponges. The cell has the closest resemblance to the choanoflagellates which are the closest related single celled protists to the animal kingdom (metazoans). The flagellae beat regularly, creating a water flow across the microvilli which can then filter nutrients from the water taken from the collar of the sponge. Food particles are then phagocytosed by the cell. ^[2]

^ Ruppert EE, Fox RS, Barnes RD (2004). Invertebrate Zoology (7th ed.). Brooks / Cole. p. 82. ISBN 978-0-03-025982-1.
^ Anderson, D. (2001) Invertebrate Zoology Oxford University Press

[1] Ruppert EE, Fox RS, Barnes RD (2004). Invertebrate Zoology (7th ed.). Brooks / Cole. p. 82. ISBN 978-0-03-025982-1.

[2] Anderson, D. (2001) Invertebrate Zoology Oxford University Press

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