Leptolebias auroguttatus and Scriptaphyosemion cauveti.
The "goby killie" and a real goby have an eerily similar color pattern. Aphyosemion franzweneri and Mugilogobius mertoni.
Rivulus and Scriptaphyosemion.
Why do so many killifish have the same tail fin?
Aphyosemion striatum and Rivulus mahadensis.