skate

As we are in the midst of playoff hockey, this post will probably get more accidental clicks from those looking for hockey-related terms, than from those interested in an ID for a fish carcass.

Last week, while walking on a rocky beach near UBC, I saw this near the low tide mark.

Carcass of something (I put it on a rock for a better photo)

While most of this organism was gone, what remained was its backbone, and a tail. I recognized its thorny tail as belonging to a skate.

Skates are one of many creatures in our waters whose existence is unknown by the general public. They seldom get caught by fisherman on piers, they don't appear at the surface, and they live too deeply to get caught in tide pools.

Skates are in the same class of animals as sharks. They share features like a cartilaginous skeleton, and a rough skin of denticles. However, their flattened body makes them well-suited for staying camouflaged on the bottom, eating crustaceans and other benthic (ocean-bottom dwelling) creatures.

Complete, one might look like this:

Big skate (image from wikipedia)

Oh wait, you're thinking, that looks like a sting ray!  Indeed, they are similar to rays in many ways, but with some differentiations:

- skates have teeth; rays have plates more suited for crushing

- skates have stockier tails with thorny protrusions, and rays have more whip-like tails that may or may not have a stinger

- skates produce egg cases, while rays give birth to live young

There are a few common species of skates in our waters, but I can't find any closeups of tails that would help me narrow down the species of the one I saw.