Question

What are collar cells?

Answer 1

Collar cells are called as the Choanocytes.Collar cells are the cells that line interior of asconiod,syconiod and lyconoid body type sponges that control a central flagellum.

Answer 2

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