Hatching Brine Shrimp
By Ed Warner
We know brine shrimp eggs are really cysts but for simplicity, this article refers to them as eggs. San Francisco nauplii [brine shrimp] are smaller than those from the Great Salt Lake. I prefer to use nauplii from the Great Salt Lake branded "O.S.I." The difference between poor, good, and great hatches, are only five minutes of preparation. There are several steps necessary to insure a great hatch. Each step is explained with its associated reasoning.
Store your eggs in a frost-free freezer or refrigerator without the lid. The frost-free unit removes moisture, thus preventing early and unnecessary hatching. Never store an open can of nauplii in your fish room because after a very short time the eggs will pick up moisture and prematurely hatch yielding less and less nauplii at each feeding. Use glass instead of plastic vessels to hatch your eggs because they add more light and are easier to clean. One gallon glass pickle jars or similar are perfect. Use clean water every time you set up. Using the same water over again is a bunch of bologna. Bacteria or parasites can build up in the water from decaying nauplii matter. These microbes eventually will disease and destroy your fish.
Allow about 3-1/2" inches from the top of the jar to allow the vessel to sit on something. This permits the eggs to easily circulate to the lower part of the jar. At the lower part of the jar you place an air-stone, weighted down with a rubber band tied to a small piece of slate or similar material. DO NOT USE SRAIGHT TUBING WITHOUT AIRSTONE. Use two tablespoons of ROCK SALT per gallon of water Rock salt will give you a better hatch than granulated salt. Put in no more than 1-1/2 teaspoon of eggs per gallon of water. If you use more than this the nauplii will die of pollution and suffocation. Aerate vigorously for 18 to 30 hours depending upon temperature. A little experimentation will tell you the amount of time the nauplii take to hatch in your fish room. In my fish room with a temperature of 74 degrees F the nauplii take 22 hours to hatch.
Now is the most important step. PROVIDE LIGHTING 24 HOURS CONTINUOUSLY. The eggs will not hatch in the dark. I use a desk lamp with a 15-watt light bulb about 18 inches above the jar. The electricity used to power this light will have a minimal impact on your electric bill and this light is necessary for a good hatch. After the elapsed hatching time place the jar in a bright area. Then place a small brown bag over the jar with about 4 inches clearance from the jar's bottom. You may have to cut the bag. The nauplii are then attracted to light and move to the bottom of the jar. The empty shells will float away from the nauplii.
After at least 7 minutes the nauplii will all be collected at the jar's bottom. Siphon water [filled with nauplii] from the jar's bottom into a small pail. I use a 3 foot piece of garden hose to siphon into a pail which is placed below the jar. Next poor the siphoned water and nauplii contents through a brine shrimp net to strain. Thoroughly wash the net caught nauplii with fresh running water. Empty all net contents into a container of fresh water and feed to fish with a baster.
Note: My experience is that micro-worms are smaller than Great Salt Lake nauplii. Which is contrary to many other authors.
Ed Warner is a well known very experienced killie fish breeder. He is the author of the popular killifish beginner's book My Success With Killifish.