+
ward
'
s
science
5100 West Henrietta Road • PO Box 92912 • Rochester, New York 14692-9012 • p: 800 962-2660 • wardsci.com
Daphnia Form and Structure
* See illustrations of "summer eggs" (developing
parthenogenically) and "winter eggs" (develop after
being fertilized) on page 3. Winter eggs have thick shell
and are produced in smaller numbers; brood chamber is
molted to form a protective ephippium.
1. Frontal organ
2. Esophagus
3. Antennal adductor muscles
4. Antenna
5. Antennal levator muscle
6. Heart
7. Ovary
8. Blood chamber
9. Thin shelled "summer eggs"
10. Abdominal process
11. Apical spine
12. Post abdomen
13. Post abdominal claw (paired)
14. Anus
15. Rectum
16. Carapace
17. Filter setae
18. 2nd & 3rd thoracic appendages
19. Shell gland
20. Maxillae (vestigial)
21. Mandible
22. Mouth
23. Labrum
24. Antennule
25. Rostrum
26. Hepatic cecae
27. Ocellus or nauplius eye
28. Optic ganglion
29. Compound eye with optic nerve
30. Nuchal or neck organ
Diagrammatic Anatomy of a Female Daphnia
1
2
3
4
5
6
7
8
9
10
11
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
*