Invertebrates Phylum Porifera

There are 2 Types of animals Vertebrates: Animals with backbones. Invertebrates: Animals without backbones. * About 97% of all animal species are inverts.

Kingdom Animalia Phylum Porifera Phylum Porifera (“pore bearers”) About 5,000 to 10,000 species Are the simplest multicellular animals Cells are independent of each other Rely on water current for food, gas exchange, excretion, & reproduction

An Introduction Turn Volume up

Porifera Most are marine (saltwater) Have tiny pores on the surface to allow water to enter & circulate through a series of canals where planktonic organisms are filtered out and eaten

Porifera Planktonic: Describes small organisms that passively float or drift in a body of water.

Porifera All are filter feeders: All are sessile: Living attached to the bottom or a surface. All are filter feeders: Actively filter suspended food from the water

Porifera: Anatomy The outer surface is covered with flat cells and sometimes tube-like pore cells called ostia, which form canals to allow water to enter. Simple sponges have one large atrium in the center which is also called a spongocoel

Fish in Atrium/Spongocoel

Porifera: Anatomy Food gets trapped here Water is pumped into a larger canal lined with collar cells also called Choanocytes, which have a flagellum that creates currents and a collar that traps food. Food gets trapped here

Porifera: Eating After choanocytes trap food on their collar, and is moved along to the base of the collar Food is then engulfed by the cell to form a food vacuole, and is digested by enzymes and pH changes Digested food is passed to amoeboid cells, & distributes it to other cells

Porifera: Anatomy Water leaves through the osculum, a large opening on the top

Sponges are Filter Feeders

Spongin Spongin: Resistant fibers for support. Magnified spongin Highly magnified spongin Spongin: Resistant fibers for support.

* Are different shapes & sizes Porifera: Anatomy Larger sponges need spicules for support * Are different shapes & sizes

Porifera: Body Forms Considered “simple sponges” 1. Ascon: Simplest & least common body form Considered “simple sponges” Porocytes regulate water circulation by contracting Ostia are the outer openings of porocytes & lead directly to a chamber called the spongocoel. Choanocytes use their flagellum to move water into the spongocoel, which then exits out the osculum.

Ascon Body Form

Porifera: Body Forms 2. Sycon is when the sponge wall appears folded Water enters through openings called dermal pores Pores contract incurrent canals, and the radial canals leads to the spongocoel Choanocytes (collar cells) line the radial canals Water travels from the ostia, through incurrent & radial canals, to the spongocoel, and out the osculum

Sycon Body Form

Porifera: Body Plan 3. Leucon: Have extensive branched canal system Considered “Complex Sponges” Water enters the sponge through ostia and moves through branched incurrent canals, which lead to choanocyte-lined chambers Canals leading away from the chambers are called excurrent canals Do NOT have a spongocoel (Atrium) Have multiple exit points (oscula) for water leaving the sponge Have increased surface area and filter large volumes of water

Leucon Body Form

Sponge Reproduction Many are asexual: branches or buds break off and grow into separate sponges identical to the original one. * No Sound *

*** What are gametes? *** Sponge Reproduction Sexually: When both sexes release gametes during the spawning season. Gametes: Haploid cells (sperm or egg) that functions in sexual reproduction. The union of 2 gametes of opposite sex produces a zygote. *** What are gametes? ***

Sponge Reproduction Spawning is the production or depositing of large quantities of eggs and sperm in water. Frog Spawn Fish Spawning Clam Spawning

More Sponge Spawning Pics.

Sponge Reproduction Zygote: Diploid Cell produced by the fusion of an egg and sperm. A fertilized egg cell. sperm Haploid Cell Zygote Diploid Cell

Are we monoecious or dioecious? Sponge Reproduction Most sponges can produce both male and female gametes in the same individual and is called monoecious Some are dioecious meaning that they have separate sexes in each individual (either male OR female…not both) We are DIOECIOUS! Are we monoecious or dioecious?

Sponge Reproduction Once the egg is fertilized, a larva is formed Larva: Is an immature stage that may undergo a dramatic change in structure before changing to the adult body form After no more than 2 days of free-swimming existence, the larva settles to the substrate and begins to develop into the adult form What is “Substrate”?

Types of Sponges Encrusting: form thin brightly colored growths on rocks or dead coral.

(example: Venus Flower Basket) Types of Sponges Glass sponges: live in deep water & have skeletons of fused silica spiclues. (example: Venus Flower Basket)

Types of Sponges Boring Sponges: bore thin channels through oyster shells and corals.

Types of Sponges Coralline Sponges: A calcium carbonate skeleton forms under the body. Once thought to be extinct, but have since been found in caves and on steep coral reef slopes.

Commercial Importance Bath Sponges: Harvested & used to bathe with Medical: Some act as antibiotics & others have painkilling properties (still researching)

Harvesting Sponges Turn Volume down

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