In the simplest case, archaeocytes line apertures in the wall of the cup-shaped sponge (this is known as ascon-grade organization). Feeding occurs in the walls of the colony. This has the hydro-dynamic effect of facilitating a good flow rate with less work from the flagella-bearing cells. They construct a skeleton with narrow openings, called ostia, through which water can enter and a broad opening through which water leaves, called the osculum. Sponges have a simple body shape, characterized by their functional needs as filter-feeding organisms (Fig. The movement of many flagellae, from many choanocytes, helps to move water through the colony. They have a funnel-shaped end, with a long flagel-lum, or whip-like filament, extending through the funnel and into the water beyond. Cho-anocytes are the cells that generate feeding currents through the sponge. Sclerocytes secrete mineralized elements of the skeleton, while spongocytes secrete the organic parts of the skeleton. These cells are feeding cells and can also change into another cell type if required. ![]() ![]() ![]() Arch-aeocytes are cells shaped like amoebae, able to move within the colony and lacking a fixed shape. Sponges are characterized by four important cell types.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |