How to Separate Baby Fish From an Adult in Aquarium

Breeding fish is a fascinating and rewarding process. Different types of fish breed and spawn differently. Some fish, such as tetras, barbs and danios scatter eggs and others, such as guppies and mollies, are live-bearers. Although some species of female fish have a period of caring for their young, most live-bearers are known for eating the young; therefore it is often necessary to separate baby fish from adult fish. An effective way to separate baby fish is using a net breeder. Purchase net breeders at any pet supply store.

Things You'll Need

  • Net breeder
  • Algae scrubber
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Instructions

    • 1

      Assemble the net breeder. A net breeder is a simple box frame, usually made out of plastic, that is covered with a fitted nylon mesh net. Net breeders fit inside of the aquarium and are used to house baby fish and keep them safe from the adults.

      Two types of net breeders include one that is completely open, where the mother has to be removed by hand just after birth, and one that has an inner partition with a vent where eggs or baby fish, when born, fall through and become separated. Some net breeders come with legs that unfold from the frame and are locked in place while others are unassembled with legs that slide into place. Always follow the assembly instruction for your particular net breeder.

    • 2

      Rinse the net breeder thoroughly by running it under tap water.

    • 3

      Place the net breeder in a corner of your aquarium. Hook the aluminum straps on the net breeder over the rim of the tank.

    • 4

      Place your pregnant female into the net breeder before she spawns. You will know when she is about to spawn when she has gotten big. Often, as with guppies, you can see the babies in the belly. Other adult fish can be left in the same aquarium.

    • 5

      Remove the female as soon as she gives birth if your net breeder does not have a partition. Most baby fishes will seek refuge in the aquarium plants by instinct. As soon as all the fry have gone to the bottom of the net breeder and inside the foliage of the plants, the mother can be removed.

    • 6

      Remove the baby fish from net breeder upon maturation. Most live-bearer fish mature in six to eight weeks, but be sure to know the maturity time for the species of fish you are breeding.

    • 7

      Clean the net breeder after each breeding session by soaking the parts in hot water to loosen the algae and then scrubbing the rest with an algae scrubber.