Dear hobbyist,The Hippo Tang will co-exist with the yellow tang .However , there are other tangs as well that should do fine. So long as they're not the same body shape . If your aquarium is large enough , you can even get away with putting three or four tangs within the same aquarium . In my 150 ,I have a yellow tang ,a hippo tang ,a clown tang , and a blonde naso tang . And they do fine together. Tangs need plenty of swimming room ,can be territorial , very aggressive , voracious eaters of seaweed ,and prone to ick . Best of luck !