I would take the shark back to the lfs as the tanks to small for him. What type of shark is it.
I wouldn't add any new fish yet with losing one.
What colour is the shark.
/www.fishlore.com/Profiles-BalaShark.htmDoes it look like this.
[URL="http/www.fishlore.com/Profiles-BalaShark.htm"]http
/www.fishlore.com/Profiles-BalaShark.htm[/URL]
Yeah thats the one.
Did they know your tank size when selling it. If not they should ask when you are buying fish.
Where is the cut on the fish and does it look infected.
They might take it back if there no white or red edging to the fin.
I would phone first and just hope they take it back.
They don't like it on there own. They have to be kept in group and need large tanks.