Skates vs. Rays: What‘s the Difference?

When most people think of cartilaginous fish, sharks are the first to come to mind. But the category also covers skates and rays—two flat, kite-shaped species of ocean dwellers closely related to sharks. They may look alike at first glance, but skates and rays are surprisingly different.

For starters, both fish belong to the Batoidea classification, a superorder of animals distinguished by their wing-like pectoral fins, flat bodies, and underside gill slits. However, rays and skates belong to distinct orders. Rays are divided into one of three: Myliobatiformes (stingrays), Torpediniformes (electric rays), and Rhinopristiformes (shovelnose rays). Meanwhile, all skates belong to the Rajiformes group.

The National Aquarium notes that rays are typically larger than skates and usually have long, whip-like tails with small or no dorsal fins. Some exceptions exist, like freshwater stingrays, which have stouter tails than their saltwater counterparts. Rays also tend to have one lobe per pelvic fin. As the stingray’s moniker implies, the fish also has venomous barbs on its tail. 

Skates, on the other hand, generally have shorter, thicker tails with two lobes per pelvic fin and small dorsal fins on their tails. Their tails and backs are also lined with thorny spikes, though they aren‘t venomous. Only a few rays, like the roughtail stingray, have similar structures on their discs and tails. 

Rays and skates share similar diets. Both fish are known to eat smaller fish, seaworms, and mollusks like clams, mussels, and crabs. Stingrays have flat plates of teeth meant for crushing prey, while the peacock-eye stingray is one of the only non-mammals known to chew its food. Skates use their tiny, pointed teeth to devour prey.

Perhaps one of the biggest and most surprising differences between skates and rays lies in how they give birth. Skates lay black, ravioli-shaped egg cases. Rays give birth to live pups.

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