mermaid 3d model

3D STL asset of a realistic female mermaid floating horizontally on her back, clean bare skin torso, smooth natural chest anatomy with zero clothing, no shells, no seaweed. Long flowing hair streaming straight out behind her head to avoid overlapping the shoulders. Lower body smoothly morphs into a realistic scaly fish tail. with a split fish tail. maintain horizontal surface on back side of object. Pure isolated model, no ocean background, zero environment artifacts, clean watertight topology engineered for 3D printing.