Multi-wavelength reflection spectra induced by an acoustically modulated fiber Bragg grating in a highly birefringent suspended core fiber are experimentally investigated. Longitudinal acoustic waves interacting with a grating generate side lobes in the reflectivity spectrum and produce a superposed reflection band. The reflectivity of up to five wavelength peaks can be actively tuned by the voltage of the electrical signal inducing the acoustic waves. This indicates new possibilities for compact and fast multi-wavelength dynamic and fiber-integrated reflection filters. Index Terms: Acousto-optic devices, microstructured fibers, fiber Bragg gratings.