I've got the portholes as well and really like them. Who could resist a schooling livebearer with the activity levels of a danio?
Not sure what information you wanted. They come from Central America (Guatemala, Honduras, southern Mexico) but I believe there are now populations in the southern US as well.
They seem happy with ordinary tropical community tank conditions, I'd say give them a fair bit of space as they are so active.
Mine eat whatever goes in the tank (flakes, veg, bloodworm), but not their own fry. I am giving them a varied livebearer diet- with some "live" food and quite a bit of veg.
The males are not aggressive but very highly sexed and spend all their time cruising just behind a female- so it is a good idea to keep 2-3 females per male, to give pregnant females a break. I have only lost one porthole and that was to an overeager male.
They practise superfetation (according to John Dawes- never actually seen mine give birth, but makes sense), so drop a few fry here and there, rather than massive batches. After 2 months/4 females, I have about a dozen fry, of very varying sizes.
The fry are extremely capable from the start and can outswim the adults pretty well from the start. The fry school at the surface for the first few weeks and then move down. They are quite a good size and can take crushed flake from the start. They grow quickly and are sexable at about 2 months.
