Nature Bulletin No. 674-A   April 7, 1962
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:THE MINNOW FAMILY

The word "minnow" is used loosely to mean almost any small fish. 
Some people even seem to think that all minnows are the young of 
larger kinds of fishes and ask what they will be when they grow up. 
This leads to misunderstandings. Minnows -- true minnows -- are 
members of a definite family of fishes just as there are the sunfish 
family, the catfish family or the trout family. To avoid confusion it is 
better to use the word "fry" for the newly hatched young and 
"fingerlings" for older juvenile fishes.

The Minnow Family has by far the greatest number of species of any 
fish family in our fresh waters. In Illinois lakes and streams, out of a 
total of more than 200 different species representing 30 fish families, 
about 50 are true minnows. They include many that are commonly 
called shiners, chubs and daces. They also include the carp and 
goldfish, which are immigrants from the Old World.

The minnows are not easily recognized because the features that set 
them apart from other fish families cannot be seen at a glance. All 
native American minnows, no matter whether they are the size of a 
book match, or that of the giant 80-pound squawfish of the Rocky 
Mountains, have these characteristics: no scales on the head, no teeth in 
the jaws, no spines in the fins, and a dorsal fin with less than ten soft 
rays.

Minnows play a most important and many-sided part in aquatic life. 
Because of their large numbers and small sizes they serve as a direct 
link in the food chain between the abundant small plant and animal life 
on which they feed and the larger carnivorous fishes which, in turn, feed 
on them. For example, it requires as little as 2 1/2 pounds of minnows 
for a bass to add one pound of weight.

Quantities of them are caught in natural waters or reared in ponds for 
bait by game fishermen. The hornyhead chub, horned dace and common 
shiner grow large enough to furnish good sport for youngsters and fly 
fishermen in the pools and rapids of our cleaner creeks. Herons, bitterns 
and kingfishers depend on them for food. Minnows aid us by eating 
mosquito wigglers.

Various types of breeding habits are found in the minnow family. The 
female carp followed by one or more males broadcasts her thousands of 
sticky eggs as she wallows and splashes through beds of water plants. 
Many small kinds merely scatter their eggs over the sand or gravel 
bottoms of lakes, ponds and streams, then leave them to hatch a week or 
two later without any further care. In many cases, the male digs or 
builds a nest to receive the eggs. He often stays to keep it clean and 
guard it against enemies. The male of the blunt-nosed minnow, 
commonest and most widespread fish in the family, finds and cleans a 
spot for the attachment of eggs on the underside of a rock, mussel shell, 
board or tin can where he stands guard until they hatch. The hornyhead 
chub and the common shiner build large nests of pebbles to receive 
their eggs. Sometimes the shiner crowds into a hornyhead's nest. As a 
result a few of the eggs are cross-fertilized to produce hybrids between 
the two.

Among all of these nest-builders the males are larger than the females. 
During the breeding season only, each of these wears his own spring 
plumage of bright colors and is specially equipped with horns, bumps 
and knobs called pearl organs.

Small streams, small fish and small people belong together. When we 
are young, flowing water, although only a step across, attracts us like a 
magnet. Anyone fortunate enough to have grown up in a neighborhood 
with a clean, natural creek seldom regrets that he lived in the days 
before comic books and television.