This is the Arctic Grayling Wire Loop Earring in Sterling Silver. The photo shown is of the Highlighted version.
Once native to northern Michigan (near me), but has now gone extinct due to lumbering in the last century. They are still found in a few places within the United States. There are small populations of it out west and you can find it in pretty good abundance in Alaska.
The unusual shaped, colorful dorsal fin is what is the unique feature of this species.
There are 3 versions available. The Original Version has just black diamond eyes. The Highlighted version the diamond eyes and has black enamel paint on the tail and dorsal fin to show contrast. The other option is the fully enamel painted version. In the photo gallery you can see all the options. If you have a photo of a special catch and want to honor its beauty in a pendant, I can mimic the colors and markings from your photo.
If interested in the 14K Gold option, just contact me for the current price quote. Please allow 2-3 weeks as these are made to order.