Sahuagin are not to be trusted. They are an infestation that cannot be rooted out, for it seems as soon as an enclave will form to wipe out a fortress, another pops up somewhere else. The only blessing is that they find those of the dry lands easier prey than those below, and frequently hunt them instead. Of course they cannot be left to their own devices, allowed to spread unchecked...everyone is their enemy. No one is safe. But the Sea-elves and the Tritons are in pact against them, and no major conflicts have occurred for generations. Avoid them, and if you hear the horns....flee for your lives.
It is considered extremely bad luck to verbally acknowledge the existence of Sahuagin. Therefore, most people instead 'sign' their name, a one handed, clawed stuffing motion towards their mouth and throat, hand clenching into a fist at the end.