1. Simple Marine Animals

2. Zooplankton in the Sea
Plankton- organisms that float or drift on the ocean surface
Include unicellular protists and multicellular jelly fish
Plantlike plankton are phytoplankton
Animal-like plankton are zooplankton

3. Zooplankton Diversity
Divided into two groups:
1. Temporary zooplankton
2. Permanent zooplankton

4. Temporary zooplankton
The embryos or larvae of fish, crabs, sponges, lobsters, clams and others
Spend early part of their life cycle floating and drifting near the ocean’s surface
When they mature, they settle to the bottom where they develop into adults (no longer plankton at this point)

5. Crab, sea star, barnacle & sea urchin larvae

6. Permanent Zooplankton
Species that remain in the plankton population throughout their entire life cycle
Ex. Foraminiferans
Unicellular
Encased in a shell or test
Made of calcium carbonate (CaCO3)
Shell falls to the seafloor when they die

8. Ex. Radiolarian
Transparent because its cell wall is made of silica
Have long spines that help with buoyancy & protection

9. Ex. Copepod
Most numerous of all permanent zooplankton
Shrimplike
Feeds on phytoplankton like diatoms
Important link in marine food chain

10. Protozoans Single celled Protists Divided into: Ciliophora
Zoomastigina
Sarcodina

11. Ex.Ciliophora Ex. Zoomastigina Ex. Sarcodina Largest group of protozoa
All have cilia
Ex. Zoomastigina
Animal-like
Move with flagella
Euglena & dinoflagellates
Ex. Sarcodina
Move by cytoplasmic extensions called pseudopods
Includes forams, radiolarians, and amoebas

12. Sponges Classified in Phylum Porifera Benthic (bottom dwelling)
Multicellular animal with three layers:
1. Endoderm- inner layer of undifferentiated cells
2. Ectoderm- outer layer of cells
3. Mesenchyme-jellylike material between the endoderm and ectoderm

14. How does a sponge feed?
Water enters the sponge through tiny pores called Ostia
Water and wastes exit through the large hole, called the osculum, located at the top of the sponge
Collar cells inside the sponge have flagella and produce the currents that move the water
Collar cells also trap and digest food

15. Benefits of sponges:
1. Very efficient filters of the marine environment (100 liters of seawater/hour)
2. Recycle minerals back into the water

16. Rotifers Multicellular Phylum Rotifera
Live in moist sand along the shore
Draws in water through it’s mouth by cilia, eats the floating food, passes through the digestive tract and out the anus

17. Rotifer Reproduction External fertilization & development
Sexual- male sperm and female egg meets up to form a zygote
Asexual- (parthenogenesis) female produces one egg with two sets of DNA which can develop into a female rotifer

19. Bryozoans Benthic organism mistaken for a sponge
Name means “moss animal”
Microscopic multicellular animal that lives in a box shaped compartment
Branching colonies of these “boxes” of bryozoans live together on rocks, seaweeds, and shells