The researchers studied how different levels of salt in water affect the hatching and survival of sepia pharaonis larvae. They found that the best salinity for hatching was between 27.0 and 33.0, with the optimal range being 30.0 to 33.0. Higher salinity led to quicker hatching and lower mortality rates. Larvae at salinities below 24.0 had high mortality rates, while those at 24.0-33.0 had no cumulative mortality. The larvae could survive without food for 8-10 days at higher salinities. The Survival Activity Index (SAI) increased with salinity, peaking at 30.0 before decreasing. The relationship between SAI and salinity can be represented by a quadratic equation.