Multires modifier is added to the starfish model, but not applied so the levels of detail are adjustable. These renders were rendered using the Blender Internal render engine with some post-processing using its built-in compositor.
Everything seen in the image is included, with the exception of the wireframe meshes and caustics. This setup includes:
+ The starfish and texture + The sand and texture + A basic underwater lighting setup (minus the caustics) + A node setup to improve the image through post-processing