Fig. 3. Cumulative mortality and LC50 of Artemia salina, instar I stage, immersed in the
ethanol extract of the red seaweed Gracilaria fisheri at different concentrations.
3.2. Safety test for the ethanol extract
A. salina instar I larvae showed no mortality when incubated
with ethanol extracts at concentrations lower than 1.0 mg ml1 for
24 h (Fig. 3). Increasing mortality was observed at increasingly
higher concentrations and the resulting LC50 was 4.29
0.5 mg ml1.