Sponges /Cozapr07/sponges2.jpg 09white_sponges_dss.jpg

Some Classes of Sponges Glass sponges Demosponges Calcareous sponge es/education/deepsea/images/glass_sp onge.jpg /77/Barrel6.jpg/250px-Barrel6.jpg / web/pages/tunicate-or-sponge- 1_jpg.htm&usg 7/SpongeBob-standup.jpg

Body Cavity+ Symmetry No organs, multicellular, and lacks true tissue Water is drawn though the sponge though the spongocoel and then water flows out of a bigger opening called the osculum. Consists of 2 layers of cells separated by mesohyl which is made from a gelatinous substance. Amoebcytes- cells wandering around the mesohyl with psuedopodia. No Coelom(coelom is an air filled body cavity) No definite body symmetry- asymmetrical but sometimes can have radial symmetry

Body Systems Nervous System- none Reactions to stimuli are slow, localized and barely perceptible Circulatory System- none Water and food is circulated through the spongocoel Choanocytes- the feeding cells that line the spongocoel. Have beating flagella that create a current thus drawing water through the porocytes Porocytes-form channels to allow water to pass though the epidermis Epidermis- outer layer made of tightly packed epithelial cells Amoebocyte- digest and then transport nutrients into different cells, provides structure for the sponge – sharp spicules

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More body systems Digestive System- none Suspension feeders- trap particles that go through their inner channels of their bodies Ingest food by phagocytosis Amoebocytes- psuedopodia, digest food, and carry nutrients to other cells Excretory System- none The water flows out of the osculum sponge2.jpg content/gallery/marine_articles_gallery/sponge_2.j pg

Reproductive System Hermaphroditic- have both functions of male and female They are sequential hermaphrodites First one sex and then changing into the other Or can be asexual Gametes are made from choanocytes or amoebocytes Eggs reside in mesophyl, but sperm are carried out into the water by the water current Cross fertilization in mesohyl Fertilization occurs in the mesohyl, there the zygote develops into a flaggelated swimming larvae. After settling on a substrate it becomes sessile adult

Locomotion +skeletal system + Gas Exchange No locomotion Sponges are sessile (not able to move around, attached at the base) A hollow tube made of usually lime or silicon that contains lots of openings. Have no sensory cells but will close if there is too much particulate matter in the water. Also will close when touched

Gas Exchange + Extra info Lack specialized organs or tissue for gas exchange Take in gases from surrounding water Sponges can produce various amounts of antibiotics that could potentially kill penicillin resistant viruses and bacteria.