Sharks & Rays in Aquariums: Gaining an understanding of how to keep these fishes in captive saltwater systems

The cartilaginous fishes; sharks, rays, skates and the weird chimaeras have always fascinated humans; the sharks for over-blown fear of attack (more people are killed every year by falling aircraft tools, pigs, tripping over shoelaces...); all for their grace and beauty. I have personally campaigned for decades, trying to educate people; for their protection in the wild as well as for their careful selection and adequate care by folks who would take the plunge in caring for them in captivit...