ZOOPLANKTON

1.0 INTRODUCTION


Zooplankton is a drifting animal that consume on phytoplankton, other zooplankton, and other decomposing matter which form a food web (Garrison, 2007). Many types of zooplankton migrate deeper into the water during the day and come up at night. At night, zooplankton can migrate up to the surface and feed on phytoplankton. Zooplankton communities are highly sensitive to environmental variation.  As a result, changes in their abundance, species diversity, or community composition can provide important indications of environmental change or disturbance. Emigration such as outflow losses and immigration from streams and other lakes of zooplankton are usually negligible. A general, positive correlation exists between the rates of production of phytoplankton and of zooplankton



2.0 METHODOLOGY

Zooplankton was collected by using 63µm and 120µm mesh size plankton net. The plankton net was thrown into the surface water and pull back in order to collect phytoplankton and zooplankton. Plankton net then was washed or rinse with distilled water in order to remove planktons that stick on the net surfaces. Planktons collected were then stored into a sample bottle with label by opening the valve of the plankton net. The samples from each location were bringing to the laboratory for analysis, identification by using compound microscope and dissecting microscope. The samples were then preserved by using formalin.



3.0 RESULTS AND DISCUSSION

Figure 1. Percentage abundance of zooplankton at mesh size 63µm

Figure 2. Percentage abundance of zooplankton at mesh size 120µm

The highest  percentage abundance of zooplankton in mesh size 63µm is copepod with percentage abundance 40% followed by nauplius copepod with percentage abundance 25%.Otherwise,the lowest zooplankton found is cladocerons and mysids with percentage abundance 1% respectively.

On mesh size 120 µm,the highest zooplankton that can be found is also copepod with percentage abundance 51% followed by amphipod with percentage abundance 11%.While the lowest zooplankton found is naupli crab with percentage abundance 0%.