All fyke, trap or pound nets shall be buoyed, and the buoy shall bear the registration or license number issued to the owner in figures at least six inches long and each stroke thereof not less than one-half inch wide. The figures shall be painted in black on a light background. The buoy bearing the identification of the owner shall be maintained in a conspicuous place at or near the bowl or heart of the fyke, trap or pound net. All gill nets, seines or similar devices shall have attached thereto a metal tag, furnished by the commissioner, bearing the license number of the owner. All boats used to set or tend lobster pots, gill nets, seines, traps, fykes, pounds, eel pots, otter trawls, beam trawls, balloon trawls, or similar devices licensed or registered under the provisions of section 26-142a, shall display in a conspicuous position a license or registration flag furnished by the commissioner.