How to Care for Aquarium Catfish Eggs

Corydoras catfish are valued by aquarium enthusiasts because of their unusual appearance, which includes a flat body and sloped, almost trapezoidal head, and because they are scavengers that feed on unwanted organisms that breed in aquarium gravel. These bottom-feeding fish are also unusual in that they lay eggs in the aquarium rather than giving birth to live young. Adult corydoras catfish are also prone to eating their own eggs. Therefore, you need to separate the eggs and the adult fish and prepare a separate aquarium where you can watch the eggs as they safely hatch.

Things You'll Need

  • Breeding tank with male and female catfish or half-filled 20-gallon aquarium
  • Fine gravel or sand
  • Air pump, tubing and airstone
  • Aquarium thermometer
  • 100-watt aquarium heater
  • Methylene blue or acraflavin
  • Sponge filter
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Instructions

    • 1

      Prepare a half-filled 20-gallon or larger aquarium if the eggs were not laid in a breeding tank that you had set up previously. Add gravel to the bottom of the tank and set up an air pump, airstone or other aerator, a thermometer and a 100-watt heater. Turn the heater on. Bring the water temperature to 65 degrees and maintain that temperature by alternately adjusting the heater and adding cooler water.

    • 2

      Locate the catfish eggs on your aquarium glass, filter tubes and other smooth, flat aquarium surfaces, such as natural and artificial plant leaves and stems.

    • 3

      Remove the adult catfish from the tank and return them to your main aquarium if the females laid eggs in a breeding tank, which you set up specifically for that purpose. Allow eggs laid in your main aquarium an hour or so to harden and remove as many as you can with a razor blade knife. Cut part of the plant stems and remove them with the eggs or remove the filter tubes so you can access the eggs without damaging them.

    • 4

      Transfer any collected eggs to the half-filled aquarium. Add 40 drops of methylene blue or acraflavin to the water of the half-filled aquarium or your breeding tank. Turn the air pump on and set it to its highest output setting if it has a power selector. Maintain the tank in a location where it is not subject to excessive natural or electric light.

    • 5

      Turn the power dial of your 100-watt heater up two degrees. Turn it up another two degrees every six hours until your thermometer reads 72 degrees and maintain that temperature while the eggs begin to hatch.

    • 6

      Inspect your main aquarium every day and collect and add any new eggs that you may see to the heated and treated tank of eggs. Wait three or four days from the day you transferred the eggs or the adults for the first eggs to begin to hatch, and another three or four days for them to begin swimming. Feed the fry white worms, Tubifex, brine shrimp, tablet foods, water fleas and the insides of fresh peas.

    • 7

      Install a sponge filter about three days after the first fry are born, or once most of the eggs have hatched and the fry begin to swim. Change about half-a-gallon of water every day at this point, but use a net to make sure you do not dispose of any fry with the old water. Set up a full aquarium filter and raise the water level to the full 20-gallon mark about three weeks after the first fry were born.