Newly hatched fry are usually extremely small in size. They need
excellent water quality. Isolating them in a net enclosure keeps them safe
from larger fish and can assist in maintaining proper circulation and water
quality. Fry need very small sources of food. Live foods produce the best results.
Following are 3 common fry foods:
Prepared mixes include flake-based food that has been ground to a fine powder and ingredients suspended in
liquids. Examples include Hikari First Bites powder and Wardley’s Small Fry liquid. The problem with
prepared mixes is that uneaten portions quickly pollute the water. Since the fry are
too small to be in a tank with a filter, the water quality deteriorates and the fry are
at risk. Liquid mixes also tend to settle at the bottom, while young fry tend to search
for food on the sides and top of the tank. Live foods produce better results.
If you use prepared foods with newly hatched fry, use a baster to remove
rotting food from the bottom of the tank several times a day. Also,
remove pollution from the surface by using a small cup. Pour the
polluted water into a cup and search for fry that you may have mistakenly
removed. You can use a baster to suck them up and return them to their
Infusoria is a generic term for various microorganisms that are present in
water, but can't be seen without a microscope. A specific example would be Protozoa.
Infusoria feed on bacteria and are already present in low levels in an aquarium. The
trick is to grow enough to supply young fry. If you have access to pond water, this
will suffice. If you don’t, take some water from an established tank and add some
plant material, such as lettuce or potato. Meat can be used too, but the smell is
much worse. Place the mixture in a sunny location for a couple of days. The water
will become cloudy and smelly as bacteria develop. The infusoria will increase in
numbers as they feed on the bacteria and the water will begin to clear. Aeration
will assist the process. An eye dropper or baster can be used to move the infusoria
to the tank with the
newborn fry. Be careful as the water can foul to the point it is toxic
and some sources indicate the micro-organisms can be harmful.
Plastic bottles are often used to hatch brine shrimp. Add one quart of tap water,
one tablespoon of coarse salt and two teaspoons of brine shrimp eggs. Aeration should be provided and
the temperature should be near 80F (27C). A bright light or a heater can be used to attain the proper
temperature. The eggs will hatch in 24 to 36 hours. At this point the aeration should be stopped. The
shells will float to the top and the napulii will settle on the bottom. Siphon the napulii from the bottom
into a fine mesh net, rinse with freshwater and feed to the fry.
The Shrimpery by San Francisco Bay Brand is an excellent source for making small
batches of brine shrimp. Simply add a packet, which contains salt and
eggs, to the base. Add water without salt to the clear plastic bottle
that mounts on top of this. The brine shrimp hatch without aeration
and they swim out of the saltwater into the freshwater that is in the
light. You take the clear plastic bottle off and pour the brine shrimp
and water into your aquarium. You can replace the water in the clear
bottle several times before the brine shrimp stop hatching. We've
tested it and it works well!
Brine shrimp (Artemia) are a common source of food for fry after they
matured beyond the infusoria stage. The brine shrimp must be newly hatched (napulii), so
that they are small enough to be eaten. The unhatched eggs, called cysts, can be purchased
at pet stores or online. Examples include San Francisco Bay Brand Brine Shrimp Eggs and Ocean
Star International Brine Shrimp Eggs.