If you take shiners from the river and put them in your aquarium be careful, I picked up a really nasty, and very prolific black algea that is impossible to get rid of in my tank, also be careful to NOT take any darter minnows, some are endangered or protected species and unless your a marine biologist you might have trouble knowing which are which, if in doubt put it back.... as for breeding, I've had about a dz river shiners in my tank for almost a year, no signs of reproduction...all same sex? dont breed in captivity? need special conditions? lots of unanswered questions! Smaller minnows seen to survive better in captivity than the larger ones, end of life cycle? improper diet? wrong conditions....who knows...when they die off seine some more!