1. Zooplankton Protozoa (heterotrophic protista) Rotifera Arthropoda
Archaezoa, Nanoflagellates (such as Dinoflagellates and Euglenozoa), Rhizopoda (Amoebas), and Ciliates.
Rotifera
Arthropoda
Crustaceans (Cladocera, Copepoda, Ostracoda)
[Insecta]

2. Size categories of zooplankton
Macrozooplankton
Larger than 200 um
Mostly crustacean species and some meroplankton (fish and insect larvae, zebra mussel larvae)
Microzooplankton
Smaller than 200 um
Mostly rotifers, also protozoans
Crustacean
Rotifer
homepage.ntlworld.com/flongrigg/rotifers.html

3. Classification According to Life Form
Nekton
Benthic invertebrates
Zooplankton
Phytoplankton

4. low high algae bacteria small large Importance of grazing Body size
of grazer
small
large

5. Micro-zooplankton: < 200 um
Macro-zooplankton: > 200um

6. Plankton net
Plankton trap

8. Aquatic Protozoa
Rhizopoda (amoebas)
Ciliophora (ciliates)
Archaezoa

9. stratification
Hecky and Kling (1981). The phytoplankton and proto- zooplankton of the euphotic zone of Lake Tanganyika

10. Giardia lamblia (Archaezoa)

11. Euglenozoa
Euglena
Phacus

12. Amoeba proteus, a unicellular protozoan

13. Rhizopoda (amoebas): Use of pseudopodia for feeding

14. Ciliates: Stentor (left), Paramecium (right)

16. Rotifera (Phylum) sessile or planktonic 40-2000 μm
corona
sessile or planktonic μm
densities up to several 100 per liter
well-established taxonomy
head
trophi
trunk
lorica
foot

17. Asplanchna
Rotifera
Keratella
Platias

18. Rotifer Reproduction
Rotifers usually reproduce asexually through Parthenogenesis
Entire population is diploid female. Eggs are produced which are clones of the mother
When would this be an advantage over sexual reproduction?
Haploid males produced under stressful conditions
science.kennesaw.edu/

19. Arthropoda (Phylum) Crustacea (one of four subphyla) - Mostly aquatic
Bosmina sp.
Crustacea (one of four subphyla)
- Mostly aquatic
- Two pairs of antennae
- Appendages on the abdomen
- Some 40,000 species
- Head and thorax "fused" into a cephalothorax
- Respiration with gills

20. Crustacea Cladocera (Order) Water fleas Ostracoda (Order) Seed shrimp
Copepoda (Order) Copepodes
Amphipoda (Order) Amphipods, scuds
Decapoda (Order) Crayfish
and more

21. Compound eye 2nd antennae Carapace (chitin) Ephippial eggs Foot
Cephalothorax
(head+thorax)
and abdomen
Digestive tract
Daphnia pulex

22. Cladocera Parthenogenesis (generally) filter feeders
Male
Female
Parthenogenesis
(generally) filter feeders
Susceptible to predation
Cyclomorphosis (phenotypic plasticity)

24. Vertical migration in zooplankton as a predator avoidance mechanism
Adults (1.5 mm)
Immatures (<0.8 mm)
Recently hatched nauplii (<0.3 mm)
(Zaret and Suffern, 1976)
Vertical migration in zooplankton as a predator avoidance mechanism
Diaptomus gatunensis is the dominant limnetic crustacean in Gatun Lake and has the largest body length.

25. Copepoda Sexual reproduction Three major groups
- Calanoida: Long antennae, 1 egg sac, filter feeders
- Cyclopoida: shorter antennae, 2 egg sacs, filter/raptorial feeders
- Harpacticoida: littoral filter feeders

27. Ostracoda (seed or clam shrimp)
minute crustaceans with large head, trunk reduced in size
bivalve calcareous carapace
almost all are free-living, both marine and freshwater forms
scrapers

28. mixing
Infante and Riehl, 1984

29. Oscillatoria
limnetica
Lyngbya limnetica
Microcystis aeruginosa

30. Infante and Riehl, 1984

31. Crustaceans in lowland tropical lakes Are there general patterns?
Prevalence of smaller species (< 1mm in length)
size-selective and intense predation by fish
Similar species richness as temperate lakes but generally lower population densities.
higher fish predation pressure
compete with fish for food (phytoplankton)

32. Temperate lakes Tropical lakes Fish A B B A A B Phyto- plankton
Bacteria
Crustaceans A B
Rotifers and Protozoans
Source: Nilssen 1984

33. Fig 3.43 Talling and Lemoalle
African tetras
tilapiine cichlids
Fig 3.43 Talling and Lemoalle

34. Arthropoda (Phylum) Insecta (class)
- Thirteen aquatic and semi-aquatic orders

35. Insects – Basic body plan
Thorax
Abdomen
Head
Antenna
Legs (3 pair)

36. Metamorphosis in Insects
Complete
Incomplete

37. Ecology (Feeding) Shredders: living or dead plant material
Collectors: filtering, gathering
Scrapers: grazers
Macrophyte piercers: fluid
Predators: engulfers, piercers
Parasites

38. Orders of Aquatic Insects
Collembola
Ephemeroptera*
Odonata*
Orthoptera
Plecoptera*
Hemiptera
Neuroptera
Megaloptera*
Trichoptera*
Lepidoptera
Coleoptera
Diptera
Hymenoptera
* indicates wholly aquatic orders

39. Order Diptera, family Chironomidea (midges)
Head capsule
Chironomus
Order Diptera, family Chironomidea (midges)
Chaoborus

40. Chironomus anthracinus swarming

41. Annelida – Oligochaeta
Tubifex tubifex

42. Hester-Dendy style samplers