What kept the BNMs from similarly proliferating and then out competing the spotfins?
saint_a these two species have different a niche thus direct competition is not real significant. Thus for me, both reproduced almost equally to put the pond at carrying capacity; almost a poly- culture thing.
snipe pull out our spawning device and measure the distance between the disks. They look too far apart. You want spacing to be 3-4-5mm (about 1/8"-3/16" no bigger) Your spacing looks to be 1/4" or more. Too wide of spacing and you will get few if any eggs. Spotfins are fussy. I suggest for your aquarium project add a couple more disks at the narrow spacing and see which spacing the shiner prefer. Let them educate you!
REMINDER - To those reading this thread; spottail shiner and spotfin shiner are two completely and entirely different species with very different spawning habits. Don't confuse them.
