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

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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.