@Kakapo You may be right, apparently both species are present at the aquarium and I find references online to them breeding Swell Shark. I don't have the signage for this exhibit, I assumed it was Leopard because the aquarium does conservation work with that species.
Oh, the egg cases were unlabelled? Yes, they keep and breed both species, and I cannot distinguish the egg cases, for what I see in Google the swell shark ones are more striped longitundinally, but this cannot be distinguished in this backlight image