Post on 30-Jun-2015
transcript
CrayfishDigestive
System
GeneralMembers of Phylum Arthropoda
In the Subphylum Crustacea
Found in freshwater steams and ponds worldwide
Coelomates
Triploblastic
Bilateral symmetry
Protostomes
Complete digestive system
Joined appendages
Exoskeleton made of chitin
http://islandwood.org/kids/stream_health/Images/Crayfish%20photo.jpg
Crayfish Digestive System1st- breaks apart food items
2nd- particles continue from these mouthparts to the internal system where nutrients are absorbed
3rd- true digestion takes place
Finally, waste is expelled
http://mackers.com/crayfish/internal.jpg
Necessary SystemWithout this digestive system, crayfish would not be able to:
break up food particles
secrete enzymes
absorb nutrients
store glycogen and fat
produce yolk proteins for developing eggs
store calcium prior to molting
http://2.bp.blogspot.com/-0GqhqXD3BuU/T-wgMxX6OSI/AAAAAAAABsY/_irnr4I1fl0/s1600/crayfish-with-minnow-large.jpg
Anatomical Features Foregut
-lined with cuticle that is continuous with exoskeleton
-enlarged stomach = chambers for storage, grinding and sorting
-finely grinds up particles, sending smaller ones to next region (midgut) & sending back larger particles for more grinding
Midgut
-intestine
-length varies with body shape and size, diet
-has mucous membranes that encase the remaining particles into pellets & forcefully pushing into the hindgut
Anatomical Features (Cont.)
Hindgut
-short, to anus
-dispose of the digested and undigested particles not absorbed by the crayfish
Green gland -right behind the brain of the crayfish
-gland that helps filter fluid waste from blood
-not entirely associated with the digestive system, but effects nutrients and filtration of nutrients from the foods that the animal ingests
Digestive gland
-secretes digestive enzymes and aids in the absorption of the products of digestion
Its Jobcrayfish chews food..particles pass through the
esophagus..food then enters the cardiac stomach..with the help of enzymes,cardiac stomach further breaks up the particles..food particles enter pyloric stomach which finely grinds up the particles,sending the smaller ones to midgut..sends back larger particles for more grinding.. particles small enough to exit the pyloric stomach enter the midgut.. dorsal abdominal artery removes nutrients through blood vessels and into bodily fluids..midgut's mucous membranes cover remaining particles into pellets..midgut forcefully pushes into the hindgut..hindgut dispose of the digested and undigested particles not absorbed by the crayfish.. contractions complete the food item's digestion.. wastes excreted through the anus
http://www.biologyjunction.com/images/Crayfish42D.jpg
http://crescentok.com/staff/jaskew/isr/biology/cfish5.gif
http://magickcanoe.com/crayfish/crayfish-w-eggs-large.jpg
http://www.caaquaculture.org/wp-content/uploads/2012/06/signal-crayfish.jpg
Biography Farkas, Andrea Lynn. "What Happens to the Digested Food in a
Crayfish?" EHow. Demand Media, 27 May 2011. Web. 11 Apr. 2013.
"Biology 102; Animal Biology." Biology 102; Animal Biology. N.p., n.d. Web. 11 Apr. 2013.
"Marine Bio." : Crayfish- Virtual Dissection. N.p., n.d. Web. 11 Apr. 2013.
"Two Pairs of Maxillae Serve as Accessory Mouthparts." Subphylum Crustacea. N.p., n.d. Web. 11 Apr. 2013.