Ecology, Environment and Conservation Paper

POPULATION-LEVEL OF NANNOCHLOROPSIS SP. AS AN ENRICHMENT DIET FOR MARINE ROTIFER BRACHIONUS ROTUNDIFORMIS IN MASS CULTURE TANKS

Putu Angga Wiradana, Mayadita Dwi Sani, Raden Joko Kuncoroningrat Susilo, Arif Nur Muhammad Ansori, Ni Nyoman Sri Septiani, Deny Suhernawan Yusup and Agoes Soegianto

Abstract

Rotifers are a natural food that has the potential as a major source of food for marine fish larvae. This study aims to observe the population density of Nannocloropsis sp. which plays a role in rotifer productivity. Culture of Nannocloropsis sp. and rotifers carried out in a volume of 50,000 L tanks using water media and ZA fertilizer mixture at a dose of 100 ppm, urea 10 ppm, TSP 10 ppm, NaEDTA 5 ppm, and FeCl3 2 ppm. The density of Nannochloropsis sp. and rotifers was observed using a microscope, hemocytometer, and Sedgewick rafter cell. The monitoring of water quality (temperature, salinity, and light intensity) was carried out every day in the morning and afternoon. Data were analyzed using the Microsoft Excel and displayed descriptively. The highest increase in culture density of Nannochloropsis sp. occurred on the 6th day of 20×106 cells/mL while rotifer culture occurred on the 5th day of 98 individuals/mL. The water quality observation in Nannochloropsis sp and rotifer culture showed water temperatures ranging from 27-30 °C (Nannochloropsis sp.) and 29-33 °C (rotifers), salinity range between 30-35 ppt (Nannochloropsis sp.) and 32-33 ppt (rotifers), as well as the value of light intensity obtained results ranging from 098-305 lux (Nannochloropsis sp.) and 085- 554 lux (rotifers). The result showed that Nannochloropsis sp. quality is a factor that can affect rotifers’ productivity.