Large Oblong Bowl

My first thought was 1950's or 60's Murano as the decoration resembles the popular fish design. The glass is dark blue, almost black in colour, when seen under the light it seems dark blue. Decorated with stretched pieces of white, red and brown glass. Definitely blown piece, with polished base. 14 1/2'' (38cm) long and quite heavy.Could that be Czech instead of Murano? Don't think it's modern Chinese, the quality is quite nice as well as it has some age related marks.