Fish that exhibit parental care suitable for an unheated aquarium
Right now, I have two tanks set up, a 55 gal., and a 10 gal. I plan to move all the fish out of the 10 gal. and keep only my Cherry Red Shrimp in it. There's a good colony going there now, but I have a couple of Oryzias and a few white clouds in there as well. In the 55 gal., I have nothing but shrimp, both the Cherry Red and some Ghost Shrimp (and some snails). I plan to let them build up there population before moving any fish in. I'm planning to set up a 15 gal. long some time in the next few months.
The White Clouds and the Oryzias seem to get along peacefully enough, although the latter are definitely shyer. I may keep the Oryzias in the 15 gal. (so I can see them) and put the White Clouds in the 55 gal., but I'd like to get some fairly hardy fish that exhibit some kind of parental care, ideally bi-parental. (I've wanted to try this out myself, and my eleven year old daughter is also very interested--she was bugging me about it a lot in the fall.) Do you have any suggestions for such fish that would either cohabit peacefully with the White Clouds in the 55 gal.--I'd prefer this--or else be content in the 15 gal., and which would not need a heated tank? The water can be as cold as 58F or so in the morning these days.