When most people think about cartilaginous fish, they think about sharks! There are two other species of fish that belong in the class chondrichthyes (cartilaginous fish) as well, and they are our stingrays and skates! Most of you have probably never even heard of a skate before, while rays seem to take most of the spotlight. In this article I’m going to give you some similarities and differences of stingrays and skates, so by the time you are done reading this, you can become an expert at identifying them too!
Skates and stingrays can be hard to differentiate. They can look very similar in appearance, but there are three main differences that set them apart from each other. The first difference between a skate and a stingray is their stinging barb. Most stingrays will have a stinging barb that is found midway along their tail, while a skate lacks a stinging barb in general. Most skates have enlarged thorn-like scales along the midline of their back or tail, which helps to act as their defense mechanism.
The second difference that sets skates and stingrays apart involves their pelvic fin. On a stingray, each one of their pelvic fins is one lobe. While on a skate, their pelvic fins are each divided into two lobes. [You can see in the photos below, the differences between the pelvic fins.]
The last difference between stingrays and skates is how they produce their young. Stingrays are viviparous, which means they give live birth to their young, which are called pups. All skates on the other hand are oviparous. This means that skates lay eggs otherwise known as “mermaid’s purses.” This developing embryo can live up to 12 weeks inside of its egg case.
While these are several differences between stingrays and skates, they also have some similarities as well! Both of these species are flat and bottom dwelling, with their mouths on the underside of their bodies. They are also both excellent at camouflaging and hiding from their predators. They do this by covering themselves with sand and burying themselves into the ocean floor. Knowing these differences and similarities of skates and stingrays can help you distinguish them, and hopefully now you will never mistake these two cartilaginous species of fish ever again!
References: Love, Milton. Probably more than you want to know about the Fishes of the Pacific Coast. 1996.
Written By: Brooke Fox