Unraveling the potential of the green microalga, Monoraphidium littorale in rearing some copepods and cladocerans

Abstract

The development of a feeding protocol of copepods and cladocerans is of paramount significance nowadays because they are considered nutritionally enriched live feeds for rearing numerous aquaculture species. Two experiments were conducted to evaluate the suitability of the green microalga Monoraphidium littorale on the population density and egg production of copepods (Diaptomus sp., Cyclops sp.) and cladocerans (Moina sp., Diaphanosoma sp.). In the first experiment, three diets including live M. littorale (T1), baker’s yeast (T2), and a combination of live M. littorale and baker’s yeast (T3) were fed to copepods and cladocerans for 10 days to determine the best feed. The results indicated that T1 was the best diet for the population density and egg production of Diaptomus sp. whereas T3 was best for Moina sp., Diaphanosoma sp., and Cyclops sp. In the second experiment, three concentrations of M. littorale including 1 × 105 cells mL−1 (T1), 5 × 105 cells mL−1 (T2), 10 × 105 cells mL−1 (T3), and dried powder of M. littorale (T4) were fed for 10 days to the copepods and cladocerans. T3 was found as the best diet for Diaptomus sp. where the mean maximum population density and egg production was significantly higher (P ˂ 0.05). Moina sp. exhibited the best growth and egg production both in T2 and T3; and Diaphanosoma sp. exhibited the best growth both in T2 and T4 but egg production in T2, T3 and T4. Interestingly, in case of Cyclops sp. the mean maximum population density and egg production were significantly higher (P ˂ 0.05) in T4 where powdered green microalgae M. littorale were used as feed. Based on the findings of the present research, M. littorale both in live and dried powdered form may be used as a suitable feed for the culture of copepods and cladocerans.