well mate i dunno much about them in ponds but in the wild they grow massive, alot bigger than me or you so be carefull and they do eat fish as part of a normal diet. so you may see your small fish dissapear. you may or may not know that sturgeon are the fish that produce caviar.

i dont recomend getting one that big, just turn it upside down and look at its mouth, as wierd as it may look it can eat a small fish