That depends on the fish (i.e. whether it's an egg layer or a live-bearer). Guppies and swordfish (for instance) develop a dark spot on their lower abdomen which swells as the babies develop. These fish are live-bearers. I breed fresh water angelfish. They lay their eggs in long swaths along plants or a favorite rock. I've placed several large pieces of slate in the aquarium that they seem to like to lay their eggs on. The female will swim up the slate and deposit her eggs and the male swims up behind her and fertilizes them. In a few days the babies hatch but stay "stuck" to the slate for about 72 hours until they're big enough to start swimming on their own. The adults will watch over them and protect them. It's kinda cool to watch. The babies surround the adults like a cloud. You know the female's pregnant because she'll start cleaning the slate in preparation to laying the eggs. It's difficult to actually determine that she's got eggs because she's so big to start with.
she will have a white pearl looking thing right below her bottom fin!
Male betta fish will build a "bubble nest" when they are getting interested in procreating. Betta fish do not get pregnant they lay their eggs in these nest.
The betta will have a swollen stomach.
No, unless its of the same breed
When you hold the fish it will say what kind its status(which will say pregnant) and age
the fish will have dots
Depends on the fish. Some lay eggs immediately during fertilization, so they aren't ever "pregnant". On livebearers like guppies, a swollen abdomen or enlarged gravity spot are the most common signs.
When it is floating not swimming.
Simple observation. You will either see them fighting or see the damage on the fish that indicates they have been fighting.
No, fighting fish (Bettas) are only interested in fighting with other fighting fish.
Exactly as you spelled it in your question; a Betta fish is also known as a Siamese Fighting Fish.it is spelled "Betta", or its other name, "Siamese Fighting Fish." I know alot about Betta's. :D
Of course they can. How else would we have fighting fish.
The only time a male and female betta or fighting fish should be together is when they breed. Otherwise it's better to separate them before one or the other dies.
Silver dollars do not get pregnant. They are egg layers.
I do not know. I would highly consider asking you local fish veterinarian.