Neon Tetras lay eggs. The female's belly should be obviously larger than the male's and should spawn in a few days. Some tetras also can get diseases that might make them look larger. What I do with my pregnant female guppies is I put them in a plastic container with holes poked in the sides (so water can be exchanged but fish including fry can't swim in or out) and clip it to the side of the tank (I use a magnet glass cleaner) at the top so the fish wont swim over the lip of the container. I hope this helps!
they eat them
Yes, they can.
They might eat each other's babies, so you may want to separate the pregnant moms.
Yes
No, if you leave the babies in with mom, or other guppies they will eat them. They see their babies as live food you would feed them. If you want any babies to survive, I suggest you separate them from the adults. (:
If you want to. But if you do they MIGHT kill the babies or take over and care for the other hamster's babies.
Yes because the other fish including the mother will eat the babies what you can do is get a mesh or plastic breeding net that you put in the tank with the other fish which you put the mother in when you think she is close to giving birth and after your sure she is done you take her out and leave the babies in there for about two weeks before letting them loose in the tank so there is no chance they will get eaten.
Yes so they can make friends with other fishes but as long as they don't hurt each other. Sharks that don't bite humans and other fishes they can be friends with humans and with fishes.
No, She will not kill her babies, but you have to make sure that the other rabbits do not trample on her nest. The does are usually jealous of another doe having babies. Be very carefull that the nest is protected that only the mother has the access to it.
they survive under water in the winter because the water freezes completely but,the ice is like water to them and it just freezes there DNA in place and doesnt hurt them a bit
The Fishes...
a few hours if they like each other then there pregnant for a few weeks