Instructions
Turn the fish on it underside. Minnows have barbels near their mouth and upper jaws. Immature fish, such as guppies, have pectoral fins and a forward facing fin on the pelvis.
Determine the native location of the fish species. Guppies and other immature fish are native to fresh-water environments such as those in South America. Minnows can survive and thrive in such diverse environments as swamps, rivers, streams and lakes.
Research the ecology of the species. Minnows are bottom feeders who represent the low rung on the aquatic food chain. Guppies and other immature fish eat surface level insects and zoo-plankton.
How to Tell the Difference Between Minnows & Immature Fish
Fish make wonderful pets for children and adults alike. When choosing a fish as a pet for a child keep in mind that any pet will require some level of attention and maintenance. Among the better choices for pet fish include goldfish, minnows and guppies. Minnows, while generally not the first option among pet fish, are inexpensive and require very little care. When choosing a minnow as a pet, it is recommended that the minnow be at least three months old.