These two pieces will be difficult to identify. Both labels are generic labels that were often added by stores or import companies. Neither the duck or fish strike me as being made by one of the Seguso companies.
I believe that Alex said it best when he wrote that many pieces of Murano may be impossible to identify because of the numbers of small furnaces making glass in Murano, often copying each others' styles. The best we can hope for often is to find a design that has a company label. I always love finding company labels. (One knows one is hooked on glass when the highlight of a week is finding a labeled mystery piece!