Comprehensive Proteomics Reveals Acute Osmoregulatory Responses in the Intestine of Oreochromis mossambicus Under Salinity, Alkalinity, and Combined Saline–Alkaline Stress

Abstract

Simple Summary Fish are often farmed in water that is saltier or more alkaline than freshwater, and they must cope with these changes quickly. We looked at what happened in the intestine (the gut) of Mozambique tilapia during the first 24 h in salty water, alkaline water, and a mixture of both. The gut showed tissue damage under the microscope, changes in natural defense molecules, and changes in the amounts of thousands of proteins, especially those that produce energy and those that control immunity. These results show how fish begin to respond to difficult water conditions within one day. This knowledge can help fish farmers and scientists protect fish health and improve farming in salty or alkaline waters.