I've seen multiple pieces with just that. If you look the orange fish is cracked. However it doesn't take away from the overall beauty of this piece. There are many ways to identify a true Murano piece and this information can be easily found on the internet. The signature I belive is last name first as well.
One of the tell tale giveaways of a fake are if they are crystal clear with no wavinwas in the glass. In Italy it is against the law to use lead in the crystal glass process so if it's very very clear chances are its nit an Italian Murano, but rather a Chinese made Murano or A knockoff. When you see this piece you can see the swirls in the glass from the layering upon layering which according to Murano is a dead giveaway that it's authentic. The item "Vintage signed Murano fish aquarium paperweight, Abstract shape approx. 5inx8in" is in sale since Tuesday, August 7, 2018.This item is in the category "Pottery & Glass\Glass\Art Glass\Paperweights". The seller is "robbiewoodward75" and is located in Rochester, New Hampshire. This item can be shipped worldwide.