A fish mouth seal carrier for a guide vane arrangement of a gas turbine comprises a first half-shell element and a second half-shell element bonded to it, which together form a box profile with two axial arms and two radial arms. A sealing element is arranged on one of the axial arms of the box profile. At least one of the two half-shell elements has an integrally formed axial flange for forming, with a guide vane platform, a fish mouth seal accommodating an axial flange of an adjoining moving blade radially between the guide vane platform and the axial flange of the seal carrier.