680 U. S. BUREAU OF FISHERIES 
larger fingerlings easily avoided the small hand seine that was used in the 
collecting, but the fish caught indicated a fairly even distribution, from the 
very smallest to those in the 40-millimeter class. The actual body lengths and 
the distribution for these lengths follow: 
Total number Total number 
Body length, of fish at this | Body length of fish at this 
millimeters length millimeters length 
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As to plankton, samples of net plankton were collected from May 8 to 
September 15, inclusive. The May samples showed the highest concentration of 
the season, and even this was very low in comparison to most of the other ponds. 
The supply of net plankton continued to be very scarce throughout the summer. 
This was not surprising, considering the great number of young fish so small 
a pond was supporting. 
Nanoplankton was collected from July 31 to September 15, inclusive. The 
amount of nanoplankton was several times that of the net. 
There was a good supply of aquatic plants in this pond. Potamogeton was 
abundant at one end of the pond and submerged Ceratophyllum and Elodea 
also were common, A jellylike blue-green algze that floated on the surface on 
hot days also was very abundant. A scum of the ‘jelly’ had to be removed 
from the surface of the pond on two occasions. Other algze (filamentous forms) 
also was abundant, but no attempt was made to study the alge of this pond 
in any detail. Aphanizomenon, so abundant in other ponds, was not present 
ime: 13. 
The miscellaneous records taken at regular intervals include water tem- 
perature, pH, turbidity, and oxygen content. 
Pond No. B 138 was drained on October 14 and the fish were removed. The 
minnows were first culled by allowing the smaller fish to pass through the 
meshes of a net that retained the larger. Four hundred and fifty-eight large 
minnows were thus separated and counted. Only one fish of this entire lot 
was clearly an adult. The rest of the minnows were very uniform in size 
and were no larger than blackhead fingerlings hatched in the first week of 
June. The smaller fish ranged from 12 to 41 millimeters in body length at a 
weight of 500 fish to 3 ounces. The larger minnows were not weighed, but in 
comparison to D 8 bass fingerlings, these minnows would easily average 7 
ounces to 100 fish. There were 6,500 of the smaller minnows. Production 
for the pond was 6,500 small fingerlings at 39 ounces, 367 large fingerlings (458 
less the original 91) at 25.69 ounces (estimated), 6,867 total fingerling pro- 
duction, weighing 64.69 ounces. 
Production per acre was computed at 201,971 fingerlings of all sizes weighing 
approximately 119 pounds (smaller minnows at 71 pounds 11 ounces and larger 
minnows at 47 pounds 4 ounces). 
What are the possibilities of this minnow as a forage fish for bass? Of 
course, a single summer’s observations of the life history and general habits 
are not sufficient for exact conclusions, but the present observations do indicate 
that it is a valuable fish. The following facts are cited: 
1. After a size of 25 to 30 millimeters was reached, the fish were observed 
feeding on alge to a great extent. 
2. The species was prolific, having increased in numbers about seventy-five 
times by the end of the summer, 
3. It spawned on boards placed for the purpose, and thus its distribution to 
other ponds was made easy. 
4. The spawning season was of long duration. This would supply both small 
and large bass with a supply of fish food throughout the growing season. 
5. It appeared to be relished by the game fish. 
A few trials made during the summer showed that bass and erappie readily 
took to these minnows as food. A large nest of eggs in hatching condition 
were placed in a crappie pond on June 24. When the pond was drained on 
September 21 there was a survival of only 4 minnows out of hundreds that 
a a 
