CRAYFISH DISSECTION

Image from: http://www.mackers.com/crayfish/

ARTHROPODA

“Arthro” =

“pod” =

joint

foot

“jointed foot”

NAMING CRAYFISHKingdom: Phylum:

CLASS:

ANIMALIA

Arthropoda“jointed foot”

CRUSTACEA

crusta = “flexible shell”

SEGMENTED BODY

TAGMA- pl TAGMATAFusion of smaller segments to make

one bigger section

Head + thorax = cephalothorax

EXOSKELETON- (flexible)made of CHITIN (polysaccharide)PROTEINS, LIPIDS, CALCIUM CARBONATE

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

CARAPACE

Section of exoskeleton covering cephalothorax

Image from:

http://rcs.rome.ga.us/hargett/biology/arthpod/craydia.htm

CHELIPED

ROSTRUM

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

COMPOUND EYE

Antennae

Antennules

ANTENNAE- touch, taste

ANTENNULES- touch, taste, & EQUILIBRIUM

DECAPODS (10 legs) (4 pair walking legs + 2 chelipeds)

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

SWIMMERETS (5 pair)

Telson

Uropods

Image from:http://www.spc.cc.tx.us/biology/jmckinney/Studyimages/crayfish/crayfishdissectlist.html

MANDIBLE

http://www.flushing.k12.mi.us/srhigh/tippettl/biology/cray/mandible.html

Mouthparts Mandible MaxillaMaxillipeds (3 pairs)

Image from:http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

Appendages1. Walking legs 2. Cheliped 3. Maxillipeds4. 2nd maxilla

(gill bailer)5. 1st maxilla6. Mandible7. Antenna8. Antennule

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

APPENDAGESANTENNA Touch, taste

ANTENNULE Touch, taste, equilibrium

MANDIBLE Chew food

MAXILLA Manipulate food Last pair “bailers”- Move water over gills

MAXILLIPEDS Touch, taste, manipulate food

CHELIPED Capture food, defense

WALKING LEGS Locomotion, move water over gills

SWIMMERETS Move water over EGGS, transfer sperm (males) carry young/eggs (females)

UROPOD Propulsion during tailflips

Is it a MALE OR FEMALE? MALES:

first two pair of swimmerets form a channel to transfer sperm to female seminal receptacle

Image from: http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

SEMINAL RECEPTACLE & SWIMMERETS

Image from:

http://bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab-7b/Crayfish_Sexes/crayfish_sexes.hm

Females “in berry”carry developing embryos on swimmerets

http://crayfish.byu.edu/crayfish_biology.htm

REPRODUCTIVE

SEPARATE SEXES

Male and Female

EXTERNAL FERTILIZATION

sperm & eggs join outside body

INDIRECT DEVELOPMENT

Starts as a LARVA

INDIRECT DEVELOPMENT

MOLLUSKS ECHINODERMS CRUSTACEANS

TROCHOPHORE BIPINNARIA NAUPLIUS Trochophore image: http://www.okc.cc.ok.us/biologylabs/Documents/Evolution/Trochophore_larva.htmNauplius image: http://www.micrographia.com/specbiol/crustac/copepo/cope0100/cycnaup1.htmBipinnaria image:

Examine the inside of your crayfish

GILLS

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

RESPIRATORY

Exchange gasesremove nitrogen waste (AMMONIA)

Image from: http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/ Protostomes/protostomes.htm

GILLS are attached to base of walking legs.

Last pair of maxilla = “bailers” & walking move water over gills

 

Image from: http://www.aa.psu.edu/div/mns/biology/crayfish/crayfishtable.htm

GAS EXCHANGE IN GILLS

INTERNAL

http://www.aa.psu.edu/div/mns/biology/crayfish/crayfishtable.htm

http://www.aa.psu.edu/div/mns/biology/crayfish/crayfishtable.htm

CIRCULATORY

Image from:

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

OPEN CIRCULATORY SYSTEM

HEART with openings (OSTIA)

ARTERIES leaving heart but NO VEINS to return hemolymph

OSTIA

 

Image from:

http://www.quia.com/jg/265982list.html

Movie from: http://www.gsu.edu/~bioasx/heartbeat.html

PYLORIC

CARDIAC

GASTRIC MILL“teeth” inside stomach

3. DIGESTIVE GLAND 4. ADDUCTOR muscles move mouthparts 5. STOMACH

Image from:

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

DIGESTIVE

ABDOMEN

Image from:

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

2. Heart 3. Digestive (hepatopancreas) gland. 4. adductor muscle 5. stomach

Image from:

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

GREEN GLANDS collect and remove nitrogen waste (AMMONIA) and excess water

Image from:

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html

NERVOUS

Image modified from:

http://www.student.loretto.org/zoology/Graphic%20webs/Crayfish%20nervous%20system.htm

VENRAL NERVE CORDCEREBRAL GANGLIAGANGLIA along body

NERVOUS

Pair of nerves lead from the ventral nerve cord around the esophagus to the large ganglion, or brain, in the head. 

Short nerves connect the eyes, antennae, and antennules to the brain. 

http://www.flushing.k12.mi.us/srhigh/tippettl/biology/cray/ganganterior.html

COMPOUND EYE

Thousands of SENSORY HAIRS project from exoskeleton over entire body sense vibrations & chemicals

http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/crayfish.html