What is the difference between a stingray and a skate?

Skates are a type of "ray" that differ considerably from stingrays. Skates, such as the clearnose skate pictured on the left, do not possess venomous barbs like stingrays although many do have sharp thorns located on their dorsal surface and tails. Also, unlike stingrays, skates primarily live in marine habitats and rarely enter brackish or freshwater environments.  The most prominent difference between the two groups is that all stingrays give birth to live young while skates reproduce by laying eggs in leathery capsules sometimes called mermaid's purses.