Resumen de Comparative Analysis of Mono and Combined Microalgal Diets on Growth Parameters of Salmacis bicolor Larvae

M. Gobala krishnan, S. R. Radhika Rajasree, L. Aranganathan, M. G. Karthih

• The present study investigates the effect of four microalgal diets in two dietary modes viz. mono diets (Dunaliella salina, Isochrysis galbana, Chaetoceros calcitrans) and combined diet (Isochrysis galbana and Chaetoceros calcitrans) on growth parameters such as morphological development, larvae survival and metamorphosis of Salmacis bicolor species grown under laboratory conditions for a period of 25th days post fertilization. Micoralgal fatty acids compositions was determined by Gas chromatography - mass spectrometry (GC-MS). Significant difference (p < 0.05) in the growth response was observed between the mono and combined diets. Among the mono diets, better growth in terms of survival rate (45.6 ± 1.2%), larvae length (468.1 ± 3.1 μm), post oral arm length (191.5 ± 3.3 μm) and metamorphosis rate (42.41 ± 2.4%) was achived in larvae fed with mono diet: C. calcitrans. Beside, combined diet has promoted high survival rate (62.3 ± 2.1%), larvae length (642.12 ± 3.6 μm), post oral arm length (232.1 ± 2.5 μm), larvae width (410.48 ± 1.8 μm), stomach length (336.8 ± 2.6 μm) and metamorphosis rate (53.8 ± 3.2%) with high significant level (p < 0.05) compared to the mono microalgal diets treatments. The fatty acid analysis revealed high concentration of vaccenic acid (C18:1–12.34 ± 0.11 mg/ml), linoleic acid (C18:2–15.78 ± 0.25 mg/ml) n-6 PUFA and alpha-linolenic acid (C18:3–19.4 ± 0.41 mg/ml) n-3 PUFA levels in combined diet. From the observations of the present study, it was concluded that combined diet using I. galbana and C. calcitrans could be adopted as best candidate microalgal species for promoting large scale production of competent larvae of S. bicolor.