Cap, the whole idea of sharks in the aquarium is a bit controversial. Sharks provide great benefit to the environments they live in believe it or not as predators and scavengers. Your average nurse shark (if it's Ginglymostoma cirratum which I believe is common to our water's) will grow to 14 feet in the wild!. Maybe some of these refinery barons in Houston have small oceans in their basement who knows but generally people who buy sharks have no clue as to their needs and try to pawn them off to fish stores or aquariums when they get too big.

The bamboo cat shark and I thknk the epaulette shark are semi suitable species since they are not big swimmers but still a very long tank , 150+ gallons is the minimum reccomended for these. IMO these should be left in the wild but I agree they are neat if you have a HUGE tank and are willing to take really good care of it.