breeding Yo-Yo loaches?

I have two Yo-Yo loaches about 2 years old in a
20 g tank. Yesterday I noticed them engaged in an
activity that I would guess could be best described
as mating.

My books have no information on loach breeding
(they were pretty emphatic that there IS not
info. on loaches breeding in aquariums).

I really don't mind if my two loaches are having
a bit of fun (good on them...), but wondered if
I should be on the lookout for little yo-yos, with
or without string. Heck, I can't even find if
they're live bearers or egg layers!

Any info. would be appreciated.

Gail