By Joe Ravalese EESH 5 Porifera
What are Porifera • Porifera often refered to as “Sponges” are a group of organisms under the Kingdom Animalia, and Phylum Porifera. • There are about 5,000 different types of sponges under the phylum of porifera in three main classes, Hexactinellida, Demospongia, and Calcarea.
When did the Porifera branch begin? • The Porifera branch split from the metozoans in the late Precambrian era. • Porifera fossils are also some of the oldest found fossils to date and are thought to be one of the earliest animals coming pretty soon after the animal like protists
Class: Hexactinellida • Hexactinellida or glass sponges are sponges which are formed by six intersecting rays at right angles. These types of sponges are also unable to expand and contract and are regarded as one of the first lineages of the sponges
Class: Demospongia • Demospongia is the most diverse sponge group and consists of 90% of the living 5,000 species of sponges. Demospongia are characterized by their skeletons which have spongin fibers or siliceous spicules with one to four rays which do not intersect at right angles. Demospongia tend to be large and live in many different enviornments.
Class: Calcarea • Calcarea or calcareous sponges are sponges whose spicules are made of calcium carbonate. They first appeared in the late Cambrian era and have survived through the present. Calcarea are most often found in shallow tropical waters however some species can be found at depths up to 4,000 meters
Porifera Anatomy • Chaonocyte-inner layer of flagellated cells that help to sweep water through the sponges body • Amoebacyte- in the middle body region and produce skeletal fibers made of a flexible protein known as spongin and mineralized particles called spicules.
How do Porifera get nutrition? • Porifera gain nutrition by filter feeding,animals thaat collect food paricles from water passed through some type of food trapping equipment. Some porifera are carnivores and will occasionally captures small organisms with the use of their spicules.
Porifera Nutrition continued • When obtaining food porifera use their Choanocytes, which have a layer of mucus that traps the food and then engulf it. Then the Amoebacytes, pick up the food packaged in food vacuoles by the Chaonocytes, digest the food and then spread the nutrients through the rest of the cells.
How do they do gas exchange? • Porifera do gas exchange without the use of a circulatory system and blood. Gas exchange in sponges is performed by diffusion of the exterior to the cells that absorb molecular oxygen and release carbon dioxide.
How do they reproduce? • Porifera can reproduce both asexually and sexually. Asexually they reproduce when they are split apart and the pieces split off will become new individuals. Sexually they reproduce with egg and sperm with most porifera being hermaphrodites, the zygote then forms a ciliated larval stage so it can swim around and disperse.
Do porifera have a nervous system? • Porifera do not have a nervous system or a brain. They were one of the first most basic multicellular organisms and lack these features. However the cells of a porifera are able to sense and adapt to changes in their enviornment.
Shapes of life • http://www.youtube.com/watch?v=rqjF7ZYkHp4 • 24:00 regenerative cells • 29:00 dye experiment
Fun Facts • Living sponges look nothing like the common bathroom sponge, which happens to only be the skeleton of a particular sponge. • The smallest sponges can be a millimeter tall when fully grown while the largest sponge is just about as big as a barrel. • The texture of a sponge varies from extremely soft to as hard as a rock. • To prevent other sponges from attacking them, sponges can actually produce chemicals to keep those other sponges cells from growing. • Chemicals that sponges make are being used to find a cure for cancer and many other diseases. • Sponges do not have organs; they are made of special cells that carry out all the necessary processes. • In Latin, "porifera" means "pore-bearing". • If you were to break up a sponge into thousands of pieces, the cells would come back together in the exact same shape within several hours. • Sponges have no dependence on sunlight, allowing them to grow at any depth. • Only 5% of all sponges can live in freshwater; the other 95% live in salt water (oceans & seas). • One cubic centimeter of a sponge can filter more than 20 liters of water a day.
Bibliography • "Introduction to Porifera." UCMP. Web. 15 Apr. 2012. <http://www.ucmp.berkeley.edu/porifera/porifera.html>. • "Investigation." About Sponges. Web. 17 Apr. 2012. <http://tolweb.org/treehouses/?treehouse_id=3431>. • "Investigating the Evolution of Body Plan." Biology.IAstate. Web. 17 Apr. 2012. <http://www.biology.iastate.edu/Courses/211L/Porif/%20Porifindx.htm>. • "Phylum Porifera Review FromBiology Questions and Answers." Porifera. Web. 18 Apr. 2012. <http://www.biology-questions-and-answers.com/porifera.html>. • "Phylum Porifera:Sponges." Thephylumporiferaproject. Web. 18 Apr. 2012. <http://thephylumporiferaproject.wikispaces.com/>.