Leni-
The fishes do seem to bear some family resemblance, but popular forms of fish and fowl were produced by more than one glass factory. I've seen your piece (i.e. with gold inclusions and on a stand, unlike mine) being marketed as Barbini, which is what gives me some hope. Also, the sommerso effect and palate reminds me of my signed Barbini apple and pear set.
Charles.