Design a highly detailed 3D model of an ancient sea dragon. Its body should be long and serpentine, covered in smooth, dark scales with glowing bioluminescent lines (blue or teal) running along its spine and tail. Add large, translucent fins along its back, tail, and sides like those of a lionfish. The head should have sharp, coral-like horns, glowing eyes, gill slits, and flowing tendrils like a deep-sea creature. Pose it in a swimming stance with its tail curled. Keep all limbs and fins connected to the body naturally. Avoid floating parts or scattered elements. Emphasize symmetry and elegance—this is a majestic guardian of the deep ocean, #ocean#