R. O. Jones

Changes In Pond Bottom Soils During The Initial Five Years Of Use

Bottom soil samples were taken after each draining during a five-year period from a series of 12 small earthen ponds ranging in size from 0.70 to 1.39 acres. Except in one pond, drainings occurred one or more times annually. The ponds were used to produce one or more crops of fingerling fish each year. Species cultured were largemouth bass, bluegill, channel catfish and redeal' sunfish. Chemical analyses for pH, calcium, phosphorus, potassium, carbon and nitrogen were done on each sample. All ponds except one were fertilized and supplemental feeding was done on a limited scale in some of...


Tolerance Of The Fry Of Common Warm-Water Fishes To Some Chemicals Employed In Fish Culture

The toxicity of fifteen chemicals used in vegetation control or disease treatment was studied. The fry of largemouth black bass, Micropterus salmoides, bluegill, Lepomis macrochirus, and channel catfish, Ictalurus punctatus were used as test animals. Chemicals included were three forms of silvex, three formulations of endothal, simazine, atrazine, diquat, two forms of benzenehexachloride, roccal, acriflavine, malachite green and methylene blue. Results of toxicity tests were used to arrive at a safe concentration of the various chemicals for the species of fry used as test animals....


Some Effects of Lime Applications To Warm-Water Hatchery Ponds

The results of applying ground limestone (CaCO2) and quicklime (CaO) to hatchery ponds used for the culture of bluegills (Lepomis macrochirus, Raf.) are described. Effects appeared to be beneficial in the sample of ponds treated. Quicklime was difficult to apply because of caustic effects to skin of personnel handling it. Laboratory experiments indicated that hydrated lime (Ca[OH].) could be used to produce a pH as alkaline as that obtained from quicklime provided that an equivalent amount of calcium was used in the hydrated form.