Kaswadji, Richardus F, Indonesia
Forum Pasca Sarjana Vol. 32 No. 2 (2009): Forum Pascasarjana - Articles
This research to study relation between environment parameter, plankton abundance and primary productivity with abundance of tiger prawn post larvae and milk fish fry, calculates plankton predating rate speed by tiger prawn post larvae and milk fish fry and other larva and studies plankton population dynamics, tiger prawn post larvae and milk fish fry before, at the time and after peak season. Result of research indicates that some environment parameters significant differs according to observation period and season. Highest abundance of tiger prawn post larva, milk fish fry and other larva reaches to 29067, 7733 and 54400 ind/1000 m3. Highest grazing rate to population of phytoplankton and plankton (phytoplankton + zooplankton) found when predator consisted of tiger prawn post larva, milk fish fry and other larva with grazing rate up to 125 cells/liter/hour and 129 plankter /liter/hour respectively. Highest predating rate to zooplankton population when predator consist of tiger prawn post larva and milk fish fry and there is phytoplankton as their prey up to 12 individual/liter/hour. The certain plankton species significant correlation and estimated as natural food of tiger prawn post larva and milk fish fry that is some types of diatom and crustaceae from zooplankton. Plankton population dynamics especially controlled by predator by tiger prawn post larva, milk fish fry and other larva, while influence of environment parameter is small relative. Abundance of each phytoplankton and zooplankton ranged from 583-28563 cells/liter and 22-3413 ind/liter. Average abundance of phytoplankton and zooplankton significant differs higher at peak season compare before and after tiger prawn post larva and milk fish fry season. Predator-prey relation between phytoplankton and zooplankton shows phase change which succession between phytoplankton controls to zooplankton phases with zooplankton control to phytoplankton. Abundance of plankton influences abundance of population of tiger prawn post larva and milk fish fry especially after peak season. There is concordance of time between peak abundance of tiger prawn post larva and milk fish fry and other larva with peak abundance of phytoplankton and zooplankton.
Key words : population dynamics, predating, predating rate, predator, prey, phytoplankton, zooplankton, tiger prawn post larva, milk fish fry, other larva, Pinrang
Forum Pasca Sarjana Vol. 31 No. 1 (2008): Forum Pascasarjana - Articles
The research aims to find out the existence and the most dominant rotifera in coastal territorial waters and estuaries in North Sulawesi, and their relationship with temperature, salinity, turbidity, dissolved oxygen, and nutrients. The research was conducted in Manembo-nembo, Minanga, Wori, and Tumpaan. Identification of rotifera revealed three species of rotifera from all locations, i.e. Brachionus rotundiformis, Brachionus caudatus, and Brachionus quadridentatus, with abundance value of 1984.4 ind/m3; 26.1 ind/m3; and 212.9 ind/m3 respectively. Result of analysis indicates that abundance of those three rotifera are significantly different both between locations and sampling sites. The abundance of B. rotundiformis in Manembo-nembo and Minanga is higher compared to those in Wori and Tumpaan. The abundance of B. caudatus is higher in Manembo-nembo and Minanga compared to those in Wori and Tumpaan. The abundance of B. quadridentatus is also different from the other two species, the abundance is sifnificantly different in Minanga compared to those in Manembo-nembo and Tumpaan, but is not significantly different with those from Wori. The highest abundance of B. rotundiformis was found in brackishwater pond and the lowest was in coastal area.