1. CRAYFISH DISSECTION

2. Where are crayfish classified?

3. What characteristics separate us from crayfish?

4. What’s the spread look like?
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5. Common Arthropods

6. Classifying Crayfish Kingdom: ANIMALIA Phylum: ARTHROPODA
Class: CRUSTACEA
Order: Decapoda
Family: Cambaridae
Genus: Camburus
Species: robustus,
bartonii bartonii
acuminatus
diogenes diogenes

7. Phylum: ARTHROPODA “Arthro” = jointed “pod” = foot
What are the 3 basic features of arthropods?

8. Which Structures to identify in lab?
All terms in the power point that are printed in RED.

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

10. SEGMENTED BODY

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

12. CARAPACE
Part of exoskeleton that covers the cephalothorax

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

14. COMPOUND EYE
HAS MULTIPLE LENSES

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

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

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

18. Telson
Uropods
Uropods
Uropods
Telson

19. MAXILLA – Manipulate food

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

21. MANDIBLE
Used for “crunching”

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

23. APPENDAGES ANTENNA 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

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

25. SWIMMERETS
MALES
Top pair
make a
“V”

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

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

28. INDIRECT DEVELOPMENT MOLLUSKS ECHINODERMS CRUSTACEANS TROCHOPHORE
BIPINNARIA
NAUPLIUS

29. Examining the inside of your crayfish

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

32. What keeps water moving over gills?
“BAILERS”
WALKING LEGS: are attached to gills so walking moves water
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33. INTERNAL
Heart
Stomach
Digestive gland

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

35. OSTIA

36. ADDUCTOR MUSCLES run mouthparts

37. STOMACH
PYLORIC
CARDIAC

38. GASTRIC MILL “teeth” inside stomach

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

40. GONADS (produces sex cells)

41. 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

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

43. GREEN GLANDS (#2) - collect and remove excess water & nitrogen waste (ammonia, NH3)

44. NERVOUS SYSTEM like earthworms
VENtRAL NERVE CORD
CEREBRAL GANGLIA (brain)
GANGLIA along body

45. VENTRAL NERVE CORD

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

47. Brain
Brain

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

49. THE END