Porifera Phylum Sponges

Characteristics of Sponges Simplest of all animals Adults are sessile (attached) Body contains pores (porifera means “pore-bearing”) Filter feeders “Skeleton” on which cells grow- it is nonliving Osculum- opening at the top of sponge body

Examples of sponges Glass sponge Purple Tube Sponge Colony

Examples of sponges Brown tube sponge Red Volcano Sponge

Typical sponge “body”

Cells that make up a sponge Epidermal cells- cells that cover the outside of the sponge Pore cells (porocytes)- Control the entry of water into the sponge Collar Cells (choanocytes)- Line the inner portion of a sponge. Have flagella that create a current in which water flow through the sponge

More cells Amoebocytes- located in a gel-like layer between the epidermal cells and the collar cells. Amoebocytes help digest and transport nutrients, form spicules and make reproductive cells. Spicules- these are NOT cells, but are small structures that make up the skeleton

Magnified pictures of spicules

Typical sponge “body” Label the cells

Water flow in a sponge Sponges are “filter-feeders” The choanocytes (collar cells) set up a current and their flagella capture food

Asexual Reproduction Asexual reproduction only involves one parent. The asexual form of reproduction is by budding.  Budding is where a piece breaks off of the old sponge and forms a new sponge which is an exact copy of the parent. 

Sexual Reproduction The sperm is released by the "male" sponge and enters the "female" sponge (most sponges make both male and female cells) The sperm cells enter through the incurrent pores, where the sperm will fertilize the egg.  The egg will eventually turn into larvae that will attach itself to the ocean floor and grow into an adult sponge.  Sponges are not able to produce eggs until they are the age of three.

Sponge larvae