The researchers studied how different levels of salt in the water affect the growth and immune system of young cobia fish. They tested salinity levels of 5, 10, 20, 30, and 37. The cobia grew best at a salinity of 30. Low salt levels of 5 and 10 slowed down their growth. The fish's immune system showed changes at different salt levels. Some immune factors increased at low salt levels, while others decreased. Overall, the cobia fish can grow well in salt levels between 20 and 37. Low salt levels can affect their growth and health, causing issues like fin erosion and discoloration.