I have been noticing an annoying trend in WoW - the Devs seem to lack knowledge of most aquatic animals.
They put freshwater fish in the sea at Stormwind Harbor and near Ogrimmar. I have not seen saltwater fish in fresh water, yet. There is indeed brackish water and I saw Stonescale eels in an area that could be described as such.
They call tortoises turtles and turtles terrapins which is another name for tortoise. Tortoises are dry land animals with a shell and flat feet. They do not like water all that much. Turtles have shells and feet shaped for swimming or flippers and usually live in water. Before I went diving in Thousand Needles, I thought there were NO turtles in the game, but there they were, and they are erroneously called terrapins.
It would be nice if the Devs could straighten this out once they get done with TWW and all the messes it has created.