Porifera

Author: Libby O'Neil
__**EXAMPLES**__:





__**HABITAT**__: Most sponges live in a marine environment.

__**TYPE OF COELOM:**__ Porifera lacks a coelom.


 * __ENDOSKELETON or EXOSKELETON__:** Sponges have exoskeletons made of spicules or spongin in the body wall.


 * __TYPE OF NERVOUS SYSTEM__:** Sponges do not have a nervous system.

__**FEEDER**__: Sessile filter feeder- they stay in one place and filter food from the water.

__**SYMMETRY**__: Sponges have no definite symmetry.

__**REPRODUCTION**__:
 * Sexual reproduction- In sexual reproduction, there is cross fertilization. The zygote develops into a larvae that can swim to new locations, allowing the species to spread. Can either be gonochoristic or hermaphroditic.
 * Asexual reproduction- Sponges can reproduce through budding, in which a small protuberance appears, grows, and eventually becomes a complete organism. This process can create large colonies of sponges. They can also reproduce through fragmentation. For example, if you cut up a sponge into separate parts, each part will develop into a separate organism.

__**CIRCULATORY SYSTEM**__: No formal circulatory system. However, their pores allow particles and nutrients to travel through the organism. Amoebocytes also act as a circulatory device to transport nutrients from cell to cell.

__**ENDOTHERMIC or EXOTHERMIC**__. Exothermic.

__**SEGMENTATION**__: Sponges have no segmentation.

__**WORKS CITED**__:

Mader, Sylvia S. //Biology// . 9th ed. New York: McGraw-Hill, 2007. Print.

"The Sponges (Phylum Porifera)." //The Earth Life Web// . Web. 28 Mar. 2011. .

 "The Sponges (Phylum Porifera)." The Earth Life Web. Web. 28 Mar. 2011. .

 "The Shape of Life . Porifera | PBS." PBS: Public Broadcasting Service. Web. 28 Mar. 2011. .