Whether raising minnows for an aquarium, using them for bait, or merely observing their behavior in the wild, minnows are highly adaptive fish. Their widely varying diet allows minnows to thrive in many areas.
Minnows in the Wild
Minnows, which are generally small, silvery, freshwater fish, feed on many sources in the wild. Upon hatching, the fry, or baby minnows, feed on algae, insect larvae and small aquatic insects, detritus (decomposing matter on the bottom of a pond, lake or stream), diatoms, and very small crustaceans. They occasionally eat fish eggs or small fish as well. The minnows' diet remain essentially the same through their lifespan.
Minnows in Aquariums
Captive fry are not picky eaters, either. They will survive on nearly any aquatic fish food, whether the food moves or not. Brine shrimp, pellet or flake fish food are acceptable. They do prefer food sinking in the water or on the bottom of the tank as opposed to sprinkled on top of the water.
Significance of the Minnows' Diet
One benefit of the minnows' widely varied diet is that they are easy to raise in the laboratory. The Environmental Protection Agency (EPA) uses minnows as a surrogate species for testing toxicity of chemicals. Chemicals such as pesticides that may affect the environment are tested on minnows to determine whether the chemical is safe for wildlife. If the minnows show a response to the chemical, it is assumed that other wildlife will be similarly affected.
Other Uses for the Minnow
Minnows are also used for bait and for feeding larger farmed fish, such as bass. Again, because of their varied diet and quick reproduction, they are an inexpensive and common food source in the fishing industry.
From clear streams and creeks to natural and man-made lakes, and even stagnant and brackish water, minnows are able to find food and reproduce. This varied diet and adaptability have made the minnow a very common freshwater fish.