A luminous sky-whale with translucent membranes stretched between elongated rib-bones, floating through a twilight sky where floating crystalline islands drift like boats on an ocean of clouds, whale's belly glowing with captured bioluminescent plankton creating swirling aurora patterns, scientific field notes style with hand-drawn annotations mapping migration routes and atmospheric composition, palette of soft peach twilight, deep cerulean sky, luminescent pale gold and ethereal lavender mist, Victorian natural history scientific illustration aesthetic