Related items
Showing items related by metadata.
-
No Thumbnail AvailableProjectWater quality conditions as disease related stressors in Clarias pond culture
Programme for the Development of Pond Management Techniques and Disease Control
1981Also available in:
No results found.Quality characteristics of water in two Clarias culture ponds were monitored through a grow-out cycle then assessed as stressors relating to disease and mortality. The two ponds were part of a small-scale commercial fish farm growing Clarias and Ophicephalus. The culture system was representative of the Clarias practice in Thailand where distressed fish and relatively high mortalities are typical. The two Clarias ponds, about 1,000 m2 each, were stocked with 0.6 g. fingerlings at the rate of 7 7 and 78/m2 on March 1, 1980. The fish were fed a mixture of ground trash fish and rice bran (9:1) then harvested after 5 months giving yields of 3,931 (3.73 kg/m2) and 5,088 kg (5.3 kg/m2) from pond No. 1 and pond No, 2, respectively. Correspondingly, average weights of harvested fish were 122 and 144 g, food conversion ratios were 6.4 and 4.9, and survival rates were 40.3 and 47.4%. Two incidences of relatively high mortalities were observed at the same time in each pond; the first occurred 49 to 53 days after stocking and the second was during the period 120 to 150 days after stocking. Pathological examination of the distressed and dead fish revealed that they were highly infested with Aeromonas sp. bacteria. Water conditions in the ponds were characterized by low Secchi disc transparency (av. 9 and 10 cm. through the grow-out period), very little DO (av. late afternoon values over the last 3 months of 0.8 and 1.3 mg/1), generally high CO2 values (in excess of 20 mg/1 through abou t 60 days of the cycle), high BOD (av2. 8.5 and 8.8 g O2/m3/day), and high un-ionized ammonia (2.2 and 3.0 mg/1, av. through the first 60 days). -
No Thumbnail AvailableProjectPathology, disease prevention and water quality (prawn farming in Thailand) 1980
Also available in:
No results found.This working paper contains the reports of two consultants to our project who advised on related topics. The first report (pp 1–39) is that of Dr. S. (Ken) Johnson of Texas A & M University who spent one month in Thailand in June/July 1980. During this time he also provided assistance to project THA/75/012 (Pond Management and Fish Diseases) and to marine shrimp workers in the Brackishwater Fisheries Division of the Department of Fisheries. The second report (pp40–45) was provided by Dr. Pau l A. Sandifer who was in Thailand for only 10 days, including five during which he participated in the meeting Giant Prawn 1980 and presented two papers2 on his work at the Marine Resources Research Institute in Charleston, South Carolina. In addition to presenting papers at Giant Prawn 1980, both Dr. Johnson and Dr. Sandifer chaired sessions at the meeting and contributed enthusiastically to formal and informal discussion sessions. Their visits to Thailand were well appreciated here. -
No Thumbnail AvailableProjectThe artificial reproduction and pond rearing of the African catfish Clarias gariepinus 1994
Also available in:
No results found.*
Users also downloaded
Showing related downloaded files
No results found.