Define what you mean by 'wierd'. Are you referring to natural characteristics that would make a species be considered as aesthetically different from other species? Are you referring to a species variant with a different color/pattern than others within its species? Or, are you referring to lasting after effects resulting from a birth defect or injury?
i think it should be split up into two categories one for natural fish(non deformity) and the other for birth deformity. but i dont think there are to many out the with non deformity weird fish because the stranger thay get the more money thay cost. were birth deformity's is kind a love thing only a few people will buy these fish but there are alot of them out there