I have always wondered why it is that only Betta splendens fry seem to suffer from missing ventrals when this has never been the case in any of the wild betta fry I have bred.
Usually as I am lazy my wild fry get fed only MWs and whatever else they can scrounge for in the tank up until they are big enough for grindals and blackworms. I only do 25% water changes every second day on my wild betta tanks (even those with fry) so I assume there must be MWs left decaying on the bottom of the tank.
My fry generally spend all their time scouting around on the bottom once they are a couple of weeks old, so I would think they would come into contact with whatever bacteria (if it is bacteria, I'm not really sure on specifics) causes missing ventrals.
Yet even now I can see ventral fins on all of my recent fry, even those who I did not know existed and had not been feeding for their first two months of life.
I've always been curious, as missing ventral fins are one of the main reasons I never have really plunged into breeding splendens, even though most people on this forum seem to only have a few fish if any with this problem.
Just wondering why there is this disparity, particularly when some people are so careful to avoid it and still end up with one or two fish missing ventrals.