Complete Substitution of Enriched Rotifer by AF-Artemia franciscana and Enhancing Clownfish Amphiprion bicinctus Larvae Production via Novel Microalgal Enrichment

Two experiments were performed in this investigation.  The first was established to compare the use of enriched rotifers (EROT) against  AF Artemia (AF Art)  for substituting rotifer as start feeding for Clownfish larvae and lasted 7 days. The observations showed a relatively lower capture rate in AF  Art treatments on 1^st  day, although, the intake and assimilation of AFArt nauplii were clearly observed. Accordingly, growth and survival data were non-significant. The second was performed on larvae from 8-21 days after hatching (DAH), evaluating the enrichment impact of EG Art with four microalgae spp., Chlorella salina, Tetraselmis chuii, and a novel trail (Rhodomonas salina) which represented as (CEA, TEA& REA), respectively against Nannochloroposis oculata (NEA) as control concerning growth performance, pigmentation, metamorphosis  and survival. Additionally, detection of unsaturated fatty acids grouping mainly omega3 ratios in various enriched Artemia was performed. Results revealed that the percentage of PUFA, HUFA and n-3 fatty acids were significantly higher (p < 0.01) in (REA) compared with (TEA) followed by (NEA) & (CEA), respectively. Otherwise, DHA/EPA and EPA/AA ratios were promoted in REA then NEA whereas no values for DHA/EPA were detected in both TEA & CEA treatments due to DHA absence. Larvae group C4 achieved maximum growth of 111.06 ± 0.2mg; on contrary (C2) attained the lowest results. In C4 group; metamorphosis took 9 days, while it extended to 10, 11, and 12 days in C1, C3, and C2, respectively. However, the onset pigmentation of larvae was surpassed in TEA followed by REA within 3-4 days from the beginning of the experiment shorter than NEA. Moreover, the C4 group achieved the highest survival of 80 ± 2.4%, while C2 attained the lowest records. This study authenticated the possibility of using AF-Art as the first feed to facilitate breeding intricacy as also suggested  R. salina alga enrichment as a prime candidate for improving the Clownfish industry.