Hi, and thank you for your contribution to Wikipedia!

In this case, in the chordate article, I think you misunderstood the text a little. The tetra is actually a bonefish. What is unusual is that it has a largely transparent body, whence we can see the backbone inside the living animal. I do not think this is very common among bone fishes, at least not in adult ones. Am I wrong?

I can understand that this was possible to misunderstand, since image was so dark that you hardly saw the backbone, unless you enlarged it. Therefore, I changed the image to one which hopefully illustrates the idea better.

Thanks again for your edit; if you hadn't done that, I hadn't looked carefully at the image, and hadn't changed it. I hope you'll go on to edit the articles, when you feel that you may improve them! Best regards,