Production of Rotifer, Brachionus Plicatilis (MÜLLER 1786) in a Continuous Algae System in a Helical Photobioreactor

Abstract

In the aquaculture sector, live feeds are of great importance, especially in the larval stages of some economic sea fish such as sea bream, sea bass, turbot and coral. Rotifer is an excellent food source for many marine fish larvae. Today, productivity in marine fish larvae production in hatcheries is largely dependent on Brachionus plicatilis. Rotifers are an ideal food for larvae during the first feeding period when the mouth opening is small. Rotifer is an excellent food source for many marine fish larvae. Today, productivity in marine fish larvae production in hatcheries is largely dependent on B. plicatilis. Rotifers are an ideal food for larvae during the first feeding period when the mouth opening is small. The most commonly used rotifer species in marine fish farming is B. plicatilis. The use of microalgae in the feeding of rotifers provides a more effective and reliable enrichment. In addition, microalgae have positive effects on water quality. Microalgae transfer their rich fatty acid content to the larva through the rotifer, improving the survival rate and growth of the larva.Nannochloropsis sp. (Eustigmatophyceae) are grown in marine fish hatcheries as bait for rotifers and to create a 'green water effect' in larval tanks. Continuous (compared to batches) microalgae production requires the adoption of specially designed fully enclosed and controlled photobioreactors, for example: flat sheet systems, tubular systems and coil type systems. Tubular systems are the most widely used commercial systems. Coil type systems were developed mainly to improve space utilization compared to other categories. It is among its most important advantages.In the helical photobioreactor designed in the study, the Nannochloropsis oculata algae species were put into production in a continuous system and using artificial light source (daylight) at a salt concentration of 30‰. Algae intrusion from the helical photobioreactor into the rotifer tank was done continuously for two weeks and the rotifer was harvested from the rotifer tank within 24 hours. The study was repeated three times. Cell increases and specific growth rates of Rotifer B. plicatilis were investigated by growing with a continuous algae system.As a result, in the study; Algae produced at maximum density in the continuous system in the helical photobioreactor were given to the B. plicatilis tank and harvested daily from the rotifer (B. plicatilis) culture tank for 24 hours. During the experiment, the growth performance of B. plicatilis increased 10 times on average. It is thought that the results of this study will be evaluated in order to increase the production of rotifers in marine fish farms where larval production is made and an increase in product productivity will be achieved while ensuring continuity in rotifer production.

Keywords:Nannochloropsis oculata, Brachionus plicatilis, Helical Photobioreactor, Continuous Production System, Growth rate, Cell growth, Salinity

DOI: 10.7176/JBAH/12-24-02

Publication date: December 31^st 2022