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