My mother told me today that while I was in class she approached my crowntail, who initially swam around and them came to the front of the tank to greet her. She said he them very quickly flared and it looked to her as if he flashed red before he relaxed and resumed swimming. She insists that this happened, but I am baffled on how it could because he is a metallic royal blue and black (pretty common). I was only aware that marbled fish could change color, and even they change over a period and not instantly and then back again.
Was her mind just playing tricks on her. or was this some kind of phenomenon I haven't heard of yet? Also, I consider him to be my most aggressive fish, but my mother thinks he is just excited and affectionate. How do I tell the difference?
As far as I know, iridescent-based ( green, turquoise, royal blue, steel blue ) may have red wash on their fins, and sometimes, it can only be seen in under a bright light and/or at certain angle, so if u're curious about it, try to find it :), and of course, it could be his beard ( it's under his gills ) too. I never saw a marble betta change color in a day ,yet.
"Also, I consider him to be my most aggressive fish, but my mother thinks he is just excited and affectionate. How do I tell the difference?" They're territorial, so I think he was "checking" to see who/what was "approaching" his territory then probably consider your mom as "not a threat" or "impossible for him to beat" so he just backed away LOL. Some bettas have more "confidence" or "pride" than other, usually the older their age, the higher it is. Which is why young bettas usually flare while swimming/circling around fast, and the older ones flare with calm, poise "style" , until they reach their "peak" then lowered when they grow much older (most of the time they don't bother to flare anymore).
All my boys do that flare. A lot of times have to stop them because I'm afraid they'll hurt themselves.
how do you stop that?
I tried covering the tank with a towel and turn off the lights, the flaring subsided only because the betta is tired and resumed after a couple hours...or at least when I am around the betta. The betta is not flaring at me but maybe at the reflection of the covered tank??
It's not hard enough to scare them, but they know to stop. I actually train my bettas to respond to me interacting with them on the tank.
A light flick (or a tap with my fingernail) stops them from flaring, or anything else that I don't approve of, such as attacking the oto. And me tapping with my actual finger is my way of getting them to move somewhere, which is how I alert them of falling food.