My black molly has a white spot near her anal fin. Is she pregnant?

Black spots or discoloration can be caused by elevated ammonia levels. Test water chemistry using a home test kit or submit a water sample for testing. Most pet or fish stores will do this for free or for a nominal fee. Ammonia and nitrites should be 0.25 ppm (parts per million) or less, nitrates can be 40ppm or less. Partial water chnages daily should be done to decrease ammonia levels. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Elevated ammonia levels can be caused by overfeeding, new tank syndrome or overstocking.

Hard to say from your description whether she is pregnant or ill. You can tell male from female Mollies by looking in the area of the anus. A male Molly has a so-called gonopodium. The gestation period of a molly fish is about 60 days. Female mollies can store sperm for months and may fertilize eggs as often as every 30 days, even without a male in the tank. Mollies may release 10 to 60 live babies at a time. Here is an illustration of sexing Mollies (and other live bearers)(credit: Mwahahahaa) http://photobucket.com/gallery/user/Mwahahahaa/media/bWVkaWFJZDoyMDk0MTEzNw==/?ref=

Separate him out to a quarantine tank. A bacterial or fungal infection can be treated using the appropriate medication found in the Aquarium section of the local Petco. Once he has recovered. he can be returned to the main tank. If it is early ich infection, you will need to treat the entire tank.

If you also have a male in the tank, it is very likely that she is at the beginning of pregnancy. Keep watching her and the black spot should be getting bigger and she should be getting rounder. This is a live-bearing fish, so make sure there are a lot of plants somewhere in the tank, so the babies can hide from the parents, as they will eat them.

Hello, my name is Dr. Shines and I am happy to help. There's only one photo of the Dalmatian Molly and it looks female but it's blurry. Here's a link with a photo showing a male vs female live bearer (which include mollies, platies and guppies) https://www.fishlore.com/aquariumfishforum/threads/sexing-livebearers-with-pictures.169520/ I hope this helps and please feel free to reach out any time.

Mollies do come in gold or orange colorations, but it is difficult to determine from that angle. If you can repost a broadside picture in a new question, that may make identification easier. If it is an egg laying species of fish, the third image could be an egg but I have reservations saying definitively without something for scale. It looks too large to be an egg. As an aside, if you leave the Molly fry in with adults, they will likely be eaten. You can separate the out, remove the adults, use a breeder screen or provide plenty of cover for them.

The natural antibiotic properties of Melafix work best with minor or external infections. Your Molly may be quite ill and may need more aggressive treatment. If you have other fish in the tank, especially Bettas or Gouramis, you cannot use Melafix as this could harm them. Separate the molly to a hospital tank and treat there. You will need to remove the carbon filter insert during treatment or it will filter out the Melafix. The symptoms listed may indicate bacterial infection, parasites, constipation or obstruction. If Negrito has a pinecone appearance, he may have a serious infection (dropsy) that is causing kidney failure. This would in turn cause the swollen abdomen and lack of appetite. Check the water chemistry, temperature and filtration. Ammonia and nitrites should be absent and nitrates can be present at 40ppm (parts per million) or less. Molies do best in water between 75F and 80F. Perform a partial water change if necessary to stabilize chemistry and maintain water quality. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Clean water is the best way to manage any infection. Plain aquarium salt (NOT table salt) can be used at 1 teaspoon per gallon of water but it is not recommended if your molly has dropsy. In this case, Epsom salt can be used to decrease swelling. Allow a 15-30 minute swim in a bath prepared with 1 tablespoon of Epsom salt per gallon of water. Do this in a separate container. It could help with constipation as well. If the Melafix does not help, use a product such as Kanaplex or Maracyn. These are broad spectrum antibiotics that you can find in the aquarium section of the local pet or fish store. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. Hopefully, any infection will be resolved with treatment. If it is dropsy, unfortunately, this condition has a high mortality rate.