Dalmation Molly

Question

Molly   I think my molly is knocked up, but its hard to know for sure.  We got her about a week and a half ago and at time of purchase, she was MUCH thinner. Also, it looks like her bum hole is poking out a little. I have attached a picture of the fish.

Answer
Hi Jackie!
Thank you for the picture! She's pretty!

I can almost guarantee you that your Molly is in fact pregnant. Mollies do breed constantly and since petstores mix males and females together, almost anytime you bring a female 'livebearer' home (platies, mollies, swordtails, guppies) you will usually be surprised with babies before you know it!

Female mollies can get quite big when pregnant depending upon their age. Your molly looks to be about full-grown so she could possibly have up to 60 or more babies. Though sometimes they may have as small a number as 10 fry.

The average gestation period for mollies is about 30 days or so. With the goldfish and any other fish you may have in the aquarium, the babies will likely get eaten almost as soon as they are born.

There are devices sometimes called "breeding traps" that you can put pregnant livebearing fish into so they can have their babies safely still within the tank. But in my experience, the confinement is very stressful for the mother fish to be suddenly moved into a strange contraption and usually she doesn't feel very safe.
If you would like to save the babies, when the molly starts to get pretty big you can put a tank divider in the aquarium. Tank dividers can be bought at most petstores but many people make their own. That way you can section off a special area for the molly when she has her fry.

Some people prefer to move the mother fish into a small separate tank of her own. Stock the nursery tank with plenty of bushy plants for the fry to take refuge in (the mother may eat them) and after she has the fry, you can move the mother fish back into the main aquarium and raise the babies separately.
But if you setup a brand new tank. Keep in mind it will not be established or have enough good bacteria present to keep the ammonia levels down produced by the fish. Daily water changes of about 50% would be in order and actually are vital when you're raising baby fish due to their need for frequent feedings (like 6 times a day or so).

I hope this helps you out with your molly!
Best wishes and happy fishkeeping!
Susan~