Recreates deep-ocean bioluminescence: jellyfish generate light via photoprotein reactions and propel themselves by rhythmically contracting their bell (jet propulsion), while drifting plankton flicker faintly in the water column. Each bell is a LatheGeometry hemisphere deformed live in a custom GLSL vertex shader (radial contraction driven by a sine pulse), with a fresnel term in the fragment shader producing the rim-glow. Tentacles are TubeGeometry meshes rebuilt every frame from swaying CatmullRomCurve3 control points, and the plankton field is a single additive-blended Points cloud whose visible count is controlled via geometry draw range.