Cultivation of Copepod Apocyclops royi AMBT201601 Using Microalga Tetraselmis suecica in Fresh and Cold-Storage Concentrated Forms

Copepods play a vital role in aquatic food webs and are a key live feed for the larval stages of aquatic organisms. This study investigates the cultivation of the cyclopoid copepod Apocyclops royi AMBT201601 using the microalgae Tetraselmis suecica, and compares the effects of fresh and concentrated microalgae diets. The concentrated microalgae were high-density microalgae that had been filtered and stored at 5°C. Copepods were cultured in 1-L glass bottles under controlled laboratory conditions with continuous illumination and temperature control. The results showed no significant differences (p>0.05) in the maximum total density of copepod (nauplii and adult) between the fresh and concentrated microalgae, with average densities of 42,000 ± 5,393 and 49,333 ± 7,910 individuals/L, respectively. The cultivation scale was then expanded to 50 L under indoor conditions with ambient temperature. It was found that maximum copepod densities remained comparable (p>0.05) between treatments, averaging 18,133 ± 6,047 and 14,067 ± 2,757 individuals/L for fresh and concentrated microalgae, respectively. Fatty acid analysis showed no significant differences (p>0.05) in composition between copepods fed with fresh and concentrated T. suecica. The polyunsaturated fatty acid (PUFA) 18:3n3 represented 3.19–3.64% of total fatty acids, with essential PUFAs such as 22:6n3, 20:5n3, and 20:4n6 also detected. The results indicate that A. royi AMBT201601 can be successfully cultured with concentrated T. suecica while maintaining density and nutritional quality. This method provides a viable approach for producing copepods as live feed for juvenile fish and shrimp, ensuring the availability of essential PUFAs necessary for their growth and development.