Sponges Phylum Porifera

Phylum Porifera – Pore Bearers Water flow Osculum Choanocyte Central cavity Pores Spicule Pore cell Pore Epidermal cell Archaeocyte

Groups of specialized cells, do not form true tissues or organs Sessile-attached to surface Pores allow water/plankton to circulate (suspension/filter-feeders) Asymmetry Choanocytes – collar cells that pump water in with flagella, create currents and trap food particles Osculum – large opening for water to exit Feeding, circulation, excretion, respiration Simple skeleton Spicules – transparent support structures made of calcium carbonate/silica Spongin - protein Amebocytes – mobile cells to secrete spicules and spongin

Feeding Suspension/Filter feeders-actively filtering food particles Intracellular digestion Choanocytes trap food/pass it on Amebocytes – complete digestion by transporting and storing food particles

Respiration, Feeding, Excretion Water circulation diffusion Response Lacks nervous system Produce toxins

Sexual Reproduction and Life Cycle MEIOSIS Haploid (N) Diploid (2N) Sperm from a sponge are released into the surrounding water-Spawning. Water currents carry the sperm to other sponges. New sponge Sperm (N) Mature sponge Metamorphosis (2N) Egg (N) Swimming larva Larva (2N) The zygote develops into a free-swimming larva. Water currents carry the larva until it attaches to a surface and grows into a new sponge. Sperm enter another sponge through pores. The sperm are carried to eggs inside the body wall. Sperm fertilize eggs. FERTILIZATION

Reproduction – Cont. Sexual Reproduction Gametes-sex cells developed from certain amebocytes (most sponges can produce both) Asexual Reproduction Budding-branches or buds break off and grow into separate sponges identical to parent

Types of Sponges Encrusting-form thin growths on rocks/dead coral (sometimes bright colors)

Red bearded sponge

Glass-anchored in deep-water sediments, lace-like skeleton of fused spicules (ex. Venus Flower Basket)

Boring-bore thin channels through calcium carbonate shells such as oysters and coral

Coralline/Sclero-calcium carbonate skeleton with spicules and spongin form under its body (first known as fossils)

Ecology Symbiotic relationships with bacteria, algae, protists Habitats