They will fit into any PCI slot but won't let you do anything at all with them. If there was a way to make them work on a Mediator or any other PCI board, Elbox would've made a fortune years ago. It's not only a driver problem, but most probably a hardware problem.
To put it straight: SharkPPCs have never ever existed. Elbox probably planned to remarket the Crescendo 7200 just like they did/do the Spider but gave that up soon after. Since there still are people believing in that scheme they left it on their site, possibly selling the odd Mediator board.