1. CRAYFISH DISSECTION

4. Animal Groups Image from: http://ology.amnh.org/biodiversity/treeoflife/pages/graph.html

5. ARTHROPODA “Arthro” = jointed “pod” = foot

6. Arthropods

7. Structures to identify in lab All terms in the PowerPoint that are printed in RED.

8. Classifying Crayfish Kingdom: ANIMALIA Phylum: ARTHROPODA Class: CRUSTACEA

9. EXOSKELETON- Outside body; NON-LIVING Made of CHITIN (polysaccharide with some nitrogen)

10. All animals with an EXOSKELETON must MOLT (shed their exoskeleton) to grow bigger

11. SEGMENTED BODY like earthworms

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

13. CARAPACE Part of exoskeleton that covers the cephalothorax

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

15. COMPOUND EYE HAS MULTIPLE LENSES

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

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

18. SWIMMERETS (5 pair)

19. SWIMMERETS Aid in reproduction In males – transfer sperm In females – carry eggs/young Create water currents

20. Telson Uropods Telson Uropods

21. MAXILLA – Manipulate food

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

23. MANDIBLE

24. Appendages 1.Walking legs 2. Cheliped 3. Maxillipeds 4. 2 nd maxilla (gill bailer) 5. 1 st maxilla 6. Mandible 7. Antenna 8.Antennule

25. APPENDAGES ANTENNATouch, taste ANTENNULETouch, taste, equilibrium MANDIBLEChew food MAXILLAManipulate food Last pair “bailers”- Move water over gills MAXILLIPEDSTouch, taste, manipulate food CHELIPEDCapture food, defense WALKING LEGSLocomotion, move water over gills SWIMMERETSMove water over EGGS, transfer sperm (males) carry young/eggs (females) UROPODPropulsion during tailflips

26. Is it a MALE OR FEMALE? MALES: first two pair of swimmerets form a channel to transfer sperm to female seminal receptacle

27. SWIMMERETS MALES Top pair make a “V”

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

29. REPRODUCTIVE SEPARATE SEXES Male and Female EXTERNAL FERTILIZATION sperm & eggs join outside body INDIRECT DEVELOPMENT Starts as a larva

30. Examine the inside of your crayfish

31. GILLS (#2) RESPIRATORY Exchange gases Remove nitrogen waste (AMMONIA)

33. What keeps water moving over gills? “BAILERS” WALKING LEGS: are attached to gills so walking moves water Image from: http://www.aa.psu.edu/div/mns/biology/crayfish/crayfishtable.htm

34. INTERNAL Heart StomachDigestive gland

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

38. OSTIA

39. ADDUCTOR MUSCLES run mouthparts

40. PYLORIC CARDIAC STOMACH

42. GASTRIC MILL “teeth” inside stomach

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

47. GONADS (produces sex cells)

50. Females: OVARIES – make eggs SEMINAL RECEPTACLES - store received sperm Males: TESTES – make sperm VAS DEFERENS- tubules inside that carry sperm from testes to exit opening ENDOCRINE SYSTEM: controls sexual development Also: molting, heart rate

51. ABDOMEN INTESTINE (#4) – finish digestion; absorb nutrients; collect & remove feces

52. GREEN GLANDS (#2) - collect and remove excess water & nitrogen waste (ammonia, NH 3 )

53. NERVOUS SYSTEM like earthworms VENRAL NERVE CORD CEREBRAL GANGLIA (brain) GANGLIA along body

54. VENTRAL NERVE CORD

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

56. Brain

57. AUTOTOMY & REGENERATION Crayfish have the ability to “self amputate” parts to escape predators and regenerate to repair injuries

58. THE END