Changes to Intestinal Transport Physiology and Carbonate Production at Various CO2 Levels in a Marine Teleost, the Gulf Toadfish (Opsanus beta).

Most marine teleosts defend blood pH during high CO2 exposure by sustaining elevated levels of HCO3(-) in body fluids. In contrast to the gill, where measures are taken to achieve net base retention, elevated CO2 leads to base loss in the intestine of marine teleosts studied to date. This loss is thought to occur through transport pathways previously demonstrated to be involved with routine osmoregulation in marine teleosts.