-35- 



The channel catfish a^ain yielded the greatest total weight from the most 

 turbid ponds J but other relationships appeared inconsistent. Table 8 shows 

 that the clear ponds exhibited the fastest growth rates and the lowest rates 

 of survival, while both survival and total weights were the greatest in the 

 most turbid ponds. Catfish in the intermediate ponds survived at approximately 

 the same rate as in the clear ponds, but had a slower growth and smaller total 

 weight than either the clear or muddy ponds. One would expect the growth 

 rate in the intermediate ponds to rank in an intermediate position consistent 

 with the survival rate and degree of turbidity. That it did not may be due 

 to some unknown food relationship in the ponds, or to some little understood 

 characteristic of the species. It may be that the channel catfish is able to 

 exploit the greater abundance of food in clear ponds by sight feeding, and can 

 rely quite successfully on its sensory aids in the very turbid ponds, while 

 enjoying neither advantage within certain intermediate ranges of turbidity. 

 It seems clear, however, that catfish production was considerably enhanced by 

 the muddy waters. While growth was somewhat faster in the clear ponds, this 

 was more than compensated for by the much greater rate of survival and greater 

 total weight produced in the muddy ponds. 



In spite of the morphological similarities of the ponds, the use of a 

 common water supply, their side-by-side location, and other standardizing 

 influences, the various ponds exhibited rather marked individual characteristics. 

 For example, ponds 13 and 14 were immediately adjacent, differed in size by 

 only approximately 0.007 of an acre, and received identical treatments; however, 

 pond 14 remained clear throughout the investigation, and pond 13 maintained 

 an average turbidity of 62 ppm. Ponds 11 and 12 also failed to conform to 

 expectations. Pond 12 received the greater initial weight of carp by approximately 



