The aquaculture industry commonly uses the euryhaline rotifer Brachionus plicatilis as food for various marine fish larvae. The current study examined the growth and/or egg production rates of B. plicatilis, isolated from the Nile River's Damietta estuary, considering temperature, salinity, and the concentrations of three algal diets. The microalgae species, Tetraselmis sp., Nannochloropsis sp., and Chaetoceros sp., were used as feed with various densities ranging from 2×10⁴ to 6×10⁵ cells/mL. The population density, specific growth rates (SGRs), and egg production rate (EPR) were significantly affected (P˂0.01) when fed diets of different densities. The highest population growth of 503±55.15 individuals/mL, SGR of 0.34±0.10, and EPR of 2.31±0.13 were recorded for the Tetraselmis sp. at a concentration of 6×10⁵ cells/mL. The temperature showed a significant (P<0.05) effect on growth rate and EPR. The rotifers cultured at 20°C had a higher growth rate than those grown at other temperatures. EPR was also expected to increase with increasing temperatures, except for 30°C. B. plicatilis exhibited a greater rate of population growth at salinities ranging from 15 to 20psu compared to a salinity of 30psu. It was deduced that variations in temperature and salinity affect the development rate and reproductive activity of B. plicatilis. The best food for B. plicatilis was Tetraselmis sp., followed by Nannochloropsis sp., while the Chaetoceros sp. seemed to be insufficient.