1. CRAYFISH DISSECTION
Image from:

2. EXOSKELETON- Outside body; NON-LIVING
EXOSKELETON- Outside body; NON-LIVING
Made of CHITIN (polysaccharide) PROTEINS, LIPIDS, CALCIUM CARBONATE

3. SEGMENTED BODY like earthworms

4. Head + thorax = cephalothorax
Fusion of smaller segments to make one bigger section
Head + thorax = cephalothorax

5. CARAPACE Part of exoskeleton that covers the cephalothorax
Image from:
Part of exoskeleton that covers the cephalothorax

6. CHELIPED = Pincher (defense; capture food)
CHELIPED = Pincher (defense; capture food)
ROSTRUM = “visor” protects eyes

7. COMPOUND EYE
HAS MULTIPLE LENSES

8. ANTENNAE- touch, taste
ANTENNULES- touch, taste, & equilibrium

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

10. SWIMMERETS (5 pair)

11. Telson Uropods Image from:

12. MAXILLA – Manipulate food

13. LAST PAIR of MAXILLA = “BAILERS” Keep water moving over gills

14. MANDIBLE

15. Appendages Walking legs Cheliped 3. Maxillipeds
Walking legs
Cheliped
3. Maxillipeds
4. 2nd maxilla (gill bailer)
5. 1st maxilla
6. Mandible
7. Antenna
Antennule

16. SWIMMERETS
MALES
Top pair
make a
“V”

17. Females “in berry” carry developing embryos on swimmerets

18. GILLS RESPIRATORY Exchange gases Remove nitrogen waste (AMMONIA)
Exchange gases Remove nitrogen waste (AMMONIA)
GILLS

19. Image from: http://faculty. clintoncc. suny. edu/faculty/Michael
Protostomes/protostomes.htm

20. What keeps water moving over gills?
“BAILERS”
WALKING LEGS: are attached to gills so walking moves water
Image from:

21. INTERNAL

22. OPEN CIRCULATORY SYSTEM
HEART with openings (OSTIA)
ARTERIES leaving heart but NO VEINS to return hemolymph

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

24. ADDUCTOR MUSCLES run mouthparts

25. STOMACH
PYLORIC
CARDIAC

26. GASTRIC MILL “teeth” inside stomach

27. DIGESTIVE GLAND Makes bile; finishes digestion; absorbs nutrients
Makes bile; finishes digestion; absorbs nutrients

28. GONADS

29. ABDOMEN INTESTINE – finish digestion; absorb nutrients;
collect & remove feces

30. GREEN GLANDS - collect and remove excess water & nitrogen waste (AMMONIA)

31. VENTRAL NERVE CORD
Image by Riedell/Vanderwal © 2005

32. CEREBRAL GANGLIA = BRAIN
Nerves connect
the eyes, antennae,
and antennules
to the brain.