Casts in ROM galleries look just like real animals - like the fish in the biodiversity gallery. To make them, a cast is put around the dead fish, just like the cast a doctor makes for a broken bone. When the cast hardens, it's gently removed and used as a mould. The mould is filled with fiberglass, which is then painted to look like the real animal. Every detail from the real fish can be seen... even missing scales and fins!
Assistant Curator of Ichthyology