Seriously, my science teacher freshman year of HS had nine of them in a tank at the start of the year for some experiment he was doing; he fed them bloodworms. By Christmas he had seven, IIRC; by summer he was down to four or five, and some of them had some good sized chunks missing from fins. They aren't the touchy-feeliest of creatures (on the other hand, they're FISH; the whole concept of a "pet" you can't pet has always seemed odd to me. )