We have all read stories of long-finned
bettas trying to bite their own tales off. Stories of Blood parrots becoming too deformed to eat properly. It causes extra stress, and stress affects the behavior of fish, I have never done any scientific experiments, but my balloon mollies were probobly the most aggressive fish I have ever kept.
I believe that a bubble-eye goldfish would be stressed if kept in a tank with faster less hindered fish such as a black Moore, It would be a constant struggle to get a fair share of food. Even if you fed the tank double the amount, the weaker fish sees the other fish get much more food than he dose. And stress is the result.
Makes sense. Many folks know that I've been rescuing and keeping bettas for over 11 years. I've seen almost every personality, all manor of deformity, hundreds of colors, patterns, tail types and more.
The fact that some long-finned bettas, including females, bite their own tails off, "fin nipping," "fin biting," or to put it simply, self mutilation, is an unfortunate but relatively common fact of keeping them. However, this doesn't explain whether they're more aggressive or not. In fact, in 11 years of experience, I've concluded that fin length doesn't contribute to aggressiveness. In fact, though plakats can move around easily, it doesn't make them more aggressive.
Blood parrots are almost never aggressive, at least that's what I've heard.
Obviously, blue rams are a dwarf cichlid species, but I hardly ever hear them being aggressive.
And though people always call goldfish peaceful I have first-hand knowledge, 11 years of it, that this often isn't the case. I've had goldfish attack other goldfish (ryukins for some reason tend to be more territorial, and pearlscales tend to eat more plants,) and
dojo loaches are one of the most aggressive fish I've ever kept, contrary to popular belief that they're "very peaceful." Those buggers constantly attacked my goldfish and ate the scales of my poor pearlscale. She couldn't get away from them. Then one day, I found my otherwise healthy black moor and giant orange fantail...dead.
What I'm asking is, is it really the deformity that makes them more aggressive? I understand the stress, sure, (although they've lived with it their whole life so I assume they'd be used to it,) but do they just...snap?
For example, I've had my slight limp my whole life. Although I usually don't notice it, when my inflammation gets out of control, it bothers me. I still do whatever I'm supposed to do by ignoring the pain. Sometimes it's too painful and I need a break. Maybe deformed fish could are like this - maybe they ignore til they can't take it anymore?
I don't know. I'm just saying that, in the past 11 years, I've seen hundreds of thousands of fish; from "high quality" bettas to
golden killifish with the worst back deformities. They're all different. I'm not sure if the deformity really does anything to their personalities.
