What do pregnant fish look like?

Pregnant livebearer fish initially look normal, but they appear obviously pregnant as they get closer to birthing. According to veterinarians Dr. Foster and Dr. Smith, pregnant livebearers develop a large abdomen characterized by a dark brown or black gravid spot at the back, near the anal fin.

Most livebearer fish give birth frequently if housed with males, and they can get pregnant immediately after giving birth. New batches of fish fry are born as often as every four to eight weeks and take four to six weeks to grow big enough to live with adults. Before then, fry should be kept in a separate tank and fed daphnia or another fry-suitable food.