ponds in the proportions of 3-5-7-9, as shown in Table 2. One of 

 each pair of ponds received a supplemental dry food ration, fish 

 in the other subsisted on natural foods. Feeding was at a rate 

 of 3 to 3 1/2 percent of fish body weight per day for 5 days each 

 week. The ponds were drained and censused in raid-October after 

 a growing period of about 75 days. 



Results . — Pertinent results for the project are shown in 

 Table 2. Rate of recovery of original stock averaged 7.4 percent 

 higher, average total length 5.4 percent higher, and average weight 

 of individual fish 12 percent higher in fed than in unfed popula- 

 tions. Feeding appeared to increase survival, or final recovery 

 of young by 22 percent, and pounds of final standing crop by 

 about 76 percent. Differences in densities were apparently too 

 small to influence rates of growth or survival. 



GROWTH OF CATFISH IN CAGES VS. GROWTH IN PONDS 



Materials and Methods . — In 1969 we compared the efficiency 

 of feeding catfish in cages with the feeding of equal numbers free 

 in ponds. We utilized the fish stocked as fry in the previous 

 summer, which were now Age I, with an average length of about 5 

 inches (12.7 centimeters). Thinwall electric tubing and 1/2-inch 

 mesh (1.3-centimeter mesh) hardware cloth were used to construct 

 cages that were 9.6 feet (2.93 meters) long, 4 feet (1.22 meters) 

 deep and 4 feet (1.22 meters) wide. The cages were floated by 

 styrofoam so as to create a depth of about 3 feet (0.9 meter) in 

 the cage and a water volume of about 4.27 cubic yards (3.26 cubic 

 meters) . Figure 1 illustrates the arrangement of the cages in the 

 deep end of the 1-acre (0.4-hectare) ponds. 



Four ponds were stocked with 1,500 fish free in the ponds, 

 and four received an equal number confined at a rate of 750 in 

 each of two cages. The fish were fed a floating catfish ration 

 twice daily for five days each week at an initial rate of three 

 percent of body weight per day. Late summer feeding rates were 

 less exactly known due to high mortalities and the supplementary 

 feeding of liver. The caged fish were sampled bi-weekly, and 

 these weights were used to compute the ration given to both caged 

 and uncaged populations. 



