a more complete diet, which eliminated fighting and 
high mortalities. The catfish were fed twice daily 
for 5 days each week. Daily rations were 3 percent 
of body weight per day from the start of the first 
feeding period of June 15 until September 2, and were 
then increased to 3.5 percent until the time of census 
in October. Ration amounts were determined from 
the weighing of 300 catfish from each cage every 14 
days; the uncaged catfish were not sampled. Actual 
computation of the ration was based on an average 
of all cage samples so that all populations received 
the same daily ration, both those in cages and those 
free in the pond. We now know that determination 
of the rations from cage samples only meant that 
the faster-growing uncaged fish were receiving less 
food per unit of body weight than were the caged 
catfish. 
All populations were censused by pond drainage 
n October, 1970, at which time the bass and bluegills 
vere returned to their ponds and the catfish were 
00led in one pond and held overwinter for redistribu- 
ion in the spring. 
tesults 
Gross census data for 1970 (and 1971) are shown 
n Tables 1 and 2. Standing crops for both individual 
md combined species are shown in Table 3. Re- 
overies of all sizes of fish were believed to be gen- 
TABLE 1.—Fall standing crops after one and two grow- 
ng seasons for largemouth bass (LMB) and bluegill (BG), 
yhen in the stocking combinations shown. Listed weights 
epresent averages for two populations of each of the types 
odicated. (CC — channel catfish.) 
a a 
Fall Standing 
Crops in 
Kilograms 
Per Hectare 
Original Stock, 
Spring, 1970 
Species Measured Number Kilograms 1970 1971 
Ee 
‘MB (when in pond 
with BG) 308? 3.63 33.88 72.23 
‘MB (when in pond with 
BG and caged CC) 308 3.60 39.66 80.68 
MB (when in pond with 
BG, caged and 
free CC) 308 3.80 36.88 80.14 
G (when in pond 
with LMB) 635> 12.67 67.76°¢ 232.56 
G (when in pond with 
LMBandcagedCC) 635 ieya lal eal 204.37 
G (when in pond with 
LMB, caged and 
free CC) 635 12.96 99.16°¢ 301.95 
4, 2888 populations all included 104 Age 1 fish stocked on 
2e4ae 4 adults stocked on 6/12/70, and 200 Age 0 stocked on 
: > Total lengths of bluegills ranged from 7.6 to 15.2 centi- 
eters; all were stocked within the period 4/7/70 to 5/12/70. 
_ ° Standing crops of bluegills for 1970 are incomplete because 
the Stranding and loss in drainage of small but unknown 
eights of young-of-the-year in small sizes. 
erally quite complete, with the exception of the young- 
of-the-year bluegills stranded in the dewatered vegeta- 
tion (mostly Najas spp.) which was quite abundant 
in most ponds in 1970. Although quite small in terms 
of total standing crops, the weights of the stranded 
fish were not estimated and the totals listed for blue- 
gills in 1970 must be recognized as incomplete. 
In the fall of 1970 the standing crops of bluegills 
older than Age 0 (original stock) were quite uniform 
from pond to pond, ranging from 257 to 338 in num- 
ber, and from 50.20 to 76.63 pounds (22.77 to 34.76 
kilograms) in weight. Survivals among populations 
of these older bluegills ranged from 40.5 to 53.2 per- 
cent. Age 0 bluegills were abundant in all ponds, 
but were mostly quite small and contributed rela- 
tively little to the total weights. In those ponds con- 
taining bass and bluegills, standing crops of channel 
catfish averaged 25 percent less in weight than the 
catfish in those ponds containing no bass and bluegills. 
These differences were due in part to predation on 
catfish by bass, and probably had no relation to the 
presence or absence of bluegills. 
Age 0 bass contributed very little to the fall stand- 
ing crops in 1970. No natural reproduction was ob- 
served, and the few surviving young-of-the-year origi- 
nated from the 200 fry stocked in each pond on June 
25, 1970. Survivors of this stock numbered 0 in three 
ponds, and 3, 5, and 22 in the remaining three ponds. 
Survivals among populations of older bass ranged 
from 31.5 to 75.0 percent, and weights ranged from 
26.13 pounds (11.85 kilograms) to 41.58 pounds (18.86 
kilograms ). 
As mentioned above, standing crops of channel 
catfish averaged less in the presence of bass and 
bluegills. It is probably significant that the poorest 
survival of channel catfish was associated with the 
largest survival of bass. In one pond, in which only 
34 of the 108 older bass survived (31.5 percent), the 
survival among 800 channel catfish released into the 
pond was 658 (82.2 percent), a figure quite close 
to that for the caged population in the same pond 
(689); however, in its replicated pond the survival 
of 81 bass older than Age 0 was the highest of any 
pond (75.0 percent), and the survival among the 800 
catfish released into the pond was only 371, by far 
the lowest of any population, caged or otherwise. It 
seems apparent that some predation of channel cat- 
fish by bass must have occurred in this first season 
when many of the catfish were still small enough 
to be eaten by the larger bass. 
We may consider the catfish in four categories: 
those either caged or free in the ponds with bass 
and bluegills, and those caged or free in the ponds 
without bass and bluegills. Standing crops of catfish 
free in the ponds averaged heavier than those popula- 
tions confined to cages, and catfish in ponds alone 
consistently outweighed those populations sharing the 
ponds with bass and bluegills (Table 3). However, 
3 
