The name "sturgeon" refers to any fish in the family Acipenseridae. This family has existed since the  upper Cretaceous Period and still continues to live today. Like other living fossils, these fish live long and mature late. With some species  reaching lengths of seven meters,  these bottom-feeders are quite large  creatures. They mainly stick around river deltas and estuaries, but migrate upstream for spawning.  Unlike other bony fishes, sturgeons have cartilaginous skeletons and are covered in skin adorned with bony scutes rather than scales. They have four barbels - sensory organs -  preceding their mouths that they use  to navigate by dragging them along the ground.   Sturgeon feed upon shells, small fish, and crustaceans by using their mouths to suck the food up, but  without teeth, they cannot seize  prey. They often live to sixty years  old (though some have been found over 100) and spawn for the first time  around twenty; due to this, many  species are under threat from  overfishing and environmental  pollution. As such, most of the  sturgeon family is at risk of  extinction, rendering them more  endangered than any other family. Without ceasing illegal fishing,  humans may see the end of the  sturgeon come quicker than it  should naturally.