Whole-body optical imaging of post-embryonic stage model organisms is a challenging and long sought-after goal.It requires a combination of high-resolution performance and high-penetration depth.Optoacoustic (photoacoustic) mesoscopy holds great promise, as it penetrates deeper than optical and optoacoustic microscopy while providing high-spatial resolution.However,optoacoustic mesoscopic techniques only offer partial visibility of oriented structures, such as blood vessels, due to a limited angular detection aperture or the use of ultrasound frequencies that yield insufficient resolution.We introduce 360° multi orientation (multi-projection) raster scan optoacoustic mesoscopy (MORSOM) based on detecting an ultra-wide frequency bandwidth (up to 160 MHz) and weighted deconvolution to synthetically enlarge the angular aperture.We report unprecedented isotropic inplane resolution at the 9-17 μm range and improved signal to noise ratio in phantoms and opaque 21-day-old Zebrafish.We find that MORSOM performance defines a new operational specification for optoacoustic mesoscopy of adult organisms, with possible applications in the developmental biology of adulthood and aging.