Brine Shrimp (Artemia salina)
These tiny crustaceans are members of the large order Eubranchipoda. While they do, at first glance, resemble tiny shrimp, they are not shrimp at all but quite different animals.
Brine shrimp were one of the first aquatic invertebrates to be widely raised as food for aquarium fish and remain one of the most popular today. They reside in lakes whose waters are highly salty in nature and reach only 0.33 to 0.5 inches in length. Brine shrimp are adapted to environmental conditions of extreme severity, and their tiny eggs can remain viable during prolonged droughts. This characteristic is behind their popularity as food items, as the dried eggs can be packed into containers, shipped around the world, and left to sit on pet store shelves for years until purchased.
The nutritional quality of brine shrimp may be improved by allowing them to feed for two or three days upon algae pellets (sold as food for a variety of herbivorous fish) or the liquid foods formulated for filter feeding invertebrates. Products specifically intended for use in nutrient loading brine shrimp are also available.
Brine shrimp are eagerly accepted by nearly all small predatory fish and are nearly indispensable and raising the tiny fry of many species and in keeping seahorses and pipefish. They are, however, an inadequate diet in and of themselves and should never be fed to the exclusion of other foods.
Brine shrimp eggs and adults can be purchased at most pet stores, so there really is little need to keep breeding colonies of these animals. The hatching time is dependent upon temperature, with the young, known as “naupli,” emerging within 24 hours at 85°F (29.4°C). The eggs and shrimp do best in clean, well-aerated marine water.
A variety of shrimp hatcheries are available if you wish to hatch the eggs. When raising large numbers of baby fish you may find it necessary to purchase several of these, so that a variety of different sized brine shrimp will be available at all times. The hatcheries make use of the fact that the hatched eggs float, and that the brine shrimp are attracted to light. A series of plastic dividers are used to exclude the hatched eggs and the live shrimp are attracted to a collection chamber by the presence of light.
You can also fashion your own brine shrimp hatcheries from a variety of materials. Perhaps the easiest method is to use an inverted soda bottle that is covered in black paper except for the very top of the bottle, near the cap. The hatched eggs will float, and the brine shrimp, drawn by the light, will gather at the top of the bottle. There they may be easily collected by simply unscrewing the cap. Remember that both homemade and commercial shrimp hatcheries should be provided with vigorous aeration in the form of a battery operated air stone.
Do not hatch brine shrimp eggs in the aquarium where your pets live. In their mad rush to catch this favored food, your fish will consume the eggshells along with the brine shrimp. Although quite small, the hatched eggs are very tough and indigestible to most fish and have been implicated in digestive disorders.
You should make every effort to observe the behavior and reproductive strategies of the food animals that you maintain. Many such creatures, especially the smaller crustaceans, have been little studied, and any information that you might acquire would be most helpful. You will also undoubtedly find much of great interest in observing the lives of the fascinating creatures.
