I have seven Harlequin rasboras in my 30 gallon tank with 5 black neons and a clown pleco. 5 rasboras are pretty small, and 2 are large because I have had them for a longer period of time. Recently, it has seemed to me that 2 of these smaller rasboras had paired off. Evidence: One is a male and one a female (I think), and they spend a lot of time next to each other. I really don't know much about their breeding behavior, so I don't know if harlequins even do pair off like apistos and angelfish. I also recently propagated my big anubias and moved parts to various parts of the tank. The small rasbora "pair" spend a lot of time around one of these rhizomes, and today I caught on camera some strange behavior. The female and male would both turn upside down and shimmy on the underside of the anubias leaves. Then they would go back to swimming normally around the plant. It seems to me that they are too small and young to be spawning, but could it be? Thoughts are appreciated.
Parameters and circumstances: 0 ammonia, 0 nitrite, less than 20 ppm of nitrate. Ph 7.7-7.8. I took a sample of water to Petsmart once to test for hardness, and they said the water was slightly hard, according to a test strip. I test ph, ammonia, nitrite and nitrate myself with an API liquid test kit. water changes every weekend, moderately planted with wisteria, anubias, small cryptocorynes.

Video!