Back in September 2013, I got my hands on the nicest example of a male Betta brownorum I have owned. Sadly, he passed away earlier this year, after being viciously attacked by the female. He possessed a rather large lateral blotch, which I was hoping would be passed onto his sons, and possibly some of his daughters.
Unfortunately, only two out of about dozen young fish, display a lateral blotch. The sub-adult male pictured above, has a lateral blotch that is similar in size to the original male's, while his younger brother shown below, has only very small, lateral spots on either side. Oddly enough, this younger male is also a different shade of red to his brother, and displays iridescent gold barring on the anal fin (not as visible in this particular photo).
I have always wondered, what it is that determines the presence, size and shape of the lateral blotch. Is it purely genetics, or do environmental factors also play a role? I have read about Betta brownorum whose lateral blotches have changed shape and size over time. I've also noticed that in females, this spot seems more likely to be greatly reduced in size, if not missing altogether. Locality also seems important. I have heard fish from the 'Matang' locality normally have much larger blotches than those from the 'Sibu' locality. Is this the result of simple inbreeding, or are there major differences between these two habitats?
This is a subject I've always been curious about, because I personally prefer fish that display large lateral blotches - for me, 'bigger is better'. As such, I have been rather disappointed that so many of my young fish are simply red all over. At this point they look more like Betta rutilans, than they do Betta broworum.
Hailing from Melbourne, Australia, I currently keep and breed a number of species from the coccina complex.