1. Flattened Body Shape: Rays have a very flattened body, almost like a pancake. This shape helps them to glide through the water with minimal resistance, making them efficient swimmers.
2. Large, Wing-Like Pectoral Fins: Their most distinctive feature is their massive pectoral fins, which extend from their head all the way down their body. These fins act like wings, providing lift and allowing the ray to "fly" through the water.
3. Skeletal Structure: The cartilaginous skeleton of rays is less dense than bone, which contributes to their overall buoyancy.
4. Liver Oil: While not as crucial as in some other fish, the liver of some ray species contains oil, which is less dense than water, providing additional buoyancy.
5. Sinking: Unlike fish with swim bladders, rays don't actively maintain a neutral buoyancy. They generally sink slowly, but their powerful pectoral fins allow them to easily lift themselves back up.
6. Specialized Muscles: Rays have strong muscles that help them to control their movements and maintain a stable position in the water, even when sinking.
In short, rays don't actively regulate buoyancy like fish with swim bladders. They rely on their flattened body shape, large fins, and strong muscles to glide through the water and compensate for their tendency to sink.
