TURKISH JOURNAL OF FISHERIES AND AQUATIC SCIENCES, cilt.26, sa.5, 2026 (SCI-Expanded, Scopus)
Despite progress in artificial diets, live rotifers (Brachionus plicatilis) remain essential for larval fish in marine hatcheries due to their superior digestibility, requiring additives to ensure a healthy culture. This study investigated the effects of water-based extracts from Rosmarinus officinalis (rosemary), Nigella sativa (black cumin), Lippia citriodora (lemon grass), and Origanum vulgare (thyme) on rotifer culture performance. Rotifers were cultured for 29 days with extracts at 0.25, 0.50, and 1.00 ppm and compared to a control group. All variables (extract, concentration, and time) significantly affected performance (P<0.05). The 1.00 ppm concentrations of R. officinalis and N. sativa proved most effective, yielding the highest rotifer densities (2.4x10(5 )individuals L-1). These groups also exhibited superior reproductive performance, measured by the proportion of egg-carrying females, and showed significant dose-dependent changes in swimming patterns. These findings demonstrate that 1.00 ppm extracts of rosemary and black cumin are viable, natural additives for optimizing rotifer productivity. This approach offers a sustainable method to enhance live feed quality, potentially providing significant advantages for the early larval feeding stages in marine aquaculture.