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Animal Phyla Project: Rotifers. By: Kristen Semrow and Annie Cao. Rotifera - “Wheel Bearers”. http:// www.youtube.com/watch?v=YF8OJt_pujc. Monogononta. 3 Main Classes of Rotifers. Seisonidea. Bdelloidea. Symmetry. Rotifera are BILATERAL
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Animal Phyla Project:Rotifers By: Kristen Semrow and Annie Cao
Rotifera- “Wheel Bearers” http://www.youtube.com/watch?v=YF8OJt_pujc Monogononta 3 Main Classes of Rotifers Seisonidea Bdelloidea
Symmetry Rotifera are BILATERAL They have 2 axis of orientation: front to back, and top to bottom 1 imaginary cut divides Rotifers to mirror-like halves
Body Plan Rotifers are pseudocoelomates: They have a body cavity that is not lined by mesoderm, but rather, the blastospore Also may have 1 or 2 light sensitive red eye spots
Support/ Movement System Rotifers have a foot, which ends with a toe (can have anywhere from 0-4 toes) that have a cement gland that helps the Rotifer attach to objects and move around They also move around using the cilia at the corona to propel themselves (cilia also used for eating)
Nutrition Rotifers eat… Dead/decomposing organic materials/ bacteria Unicellular algae Phytoplankton Sometimes they are cannibals ( example: Acanthocephala) Fish waste
Gas Exchange Process There are no special organs for internal transport or exchange of gasses Rotifers have a small body, which is an adaptation to facilitate transport and exchange of gasses Get necessary gasses over their body surface by diffusion of fluids
Defense Mechanisms Rotifer’s foot helps them move quickly if they sense danger from a predator Reproduction ensures survival They don’t use jaws as a weapon (only used for eating)
Excretion/ Water Balance Alimentary canal runs the entire length of the body Waste is expelled from the anus
Reproduction Rotifers reproduce asexually by parthenogenesis: Female Rotifers can produce unfertilized eggs that are clones of the mother Most of the offspring are females Unfertilized eggs can dry out If they produce males, they will be weak, won’t be able to feed themselves, and will survive long enough to reproduce
Response to Stimuli Red eye spots can help Rotifers detect danger Have brains so they can send impulses to the rest of the body Their jaws function after the cilia bring in food to consume
Other Interesting Facts Rotifer’s bodies are almost transparent Slim chances if there are male Rotifers Most Rotifers are about .5-1 mm or less Help out in natural water purification