44 ^' S. BUREAU OF FISHERIES 



Another fish considered of sufficient importance to warrant culture, 

 if it could be developed, was the sheepshead, Aplodinotus grunniens. 

 Pond culture was attempted without success, while in addition a 

 study was made of its life history at Lake Pokegama. Many hun- 

 dred slides of the scales and carefully ground otoliths of the sheeps- 

 head were prepared during the summer season by Mr. Southall and 

 two temporary assistants in order to determine the ages of the hsh 

 examined and to compare these ages with the condition of the re- 

 productive organs so that the spawning habits might be more fully 

 understood. 



Pond culture of the padcllefish, Polyodon spathula^ was attempted. 

 As a number of these fish had been in the reservoir for 10 years 

 without any results, some were placed in a pond and various pos- 

 sible spawning conveniences added, such as barrels and sunken tree 

 tops, in the hope that the fish might be induced to spawn. No re- 

 sults were obtained. The work was done rather blindly, as previ- 

 ous attempts by various investigators to become acquainted with the 

 spawning habits of these fish under natural conditions had not been 

 successful. The commercial value of the fish, which is fast being 

 depleted, was considered sufficiently great to warrant the considera- 

 tion given it. 



An effort was made to use channel catfish as pondfish, with the ex- 

 pectation that they might forage successfully for themselves, much 

 as the bluegill has done in the so-called farm pond. A number of 

 channel catfish fingerlings were placed by themselves in certain 

 ponds in the spring and removed in the fall. The available food 

 supply in these ponds was evidently unsatisfactory, for the growth 

 of the fish was insignificant, while one of the two ponds had a very 

 heavy mortality. 



Since the buffalofish, once of great commercial importance in the 

 Mississippi and its tributaries, has been greatly depleted within the 

 last few years, it has acquired an increasing interest. An effort was 

 made to determine its value as a pondfish. A bad turn of weather, 

 with a resulting heavy drop of temperature, and certain other diffi- 

 culties, apparently interfered with the spawning of the fish in 

 the ponds in which they were placed. Under the circumstances 

 the obtaining of over 12,000 young buffalofish from 26 adult Ictiohus 

 hubalus may be considered very satisfactory, and excellent future 

 returns are anticipated. 



Work with the channel catfish was continued. Twelve pairs of 

 catfish produced an average of 4,000 fingerlings each. It is thought 

 that sufficient work has been done with the channel catfish so that 

 its culture on a large hatchery scale may now be undertaken. 



The so-called farm pond was conducted as usual. The purpose 

 of this pond has been explained in detail in previous annual reports. 

 The bluegill sunfish was used as heretofore, and production was 

 at the rate of 304 pounds per acre. This compares with 440 pounds 

 in 1922, 374 poimds in 1921, 333 pounds in 1920, 203 pounds in 

 1919, and 286 pounds in 1918. The same pond was used each year, 

 and no fish food was added to the natural supply in the pond. 



