A study on performances of intensification in the farming system of a shrimp farm at Cox's Bazar, Bangladesh

This study examines the harvest and mean production in relation to the stocking of P. monodon fry during the period between March 1992 and October 1994, at the farm owned by M/s Monugung Sea Food Ltd., Cox's Bazar. The analysis shows that production figures were initially up to expectation, but after harvesting 4 crops within 16 months, production sharply decreased. The unexpected high mortality of the growing stock was due to outbreak of an uncontrollabe disease (Vibriosis). Significantly higher variations in production, survival and growth were also noted among the different treatments.

Seasonal dynamics of phytoplankton in relation to environmental factors in the Maheshkhali channel, Cox's Bazar, Bangladesh

In total 68 phytoplankton species were identified at the mouth of the Maheshkhali channel with the Bay of Bengal, among them 41 belong to Bacillariophyceae, 17 Dinophyceae, 7 Cyanophyceae and 3 to Chlorophyceae. The highest phytoplankton production was observed in November (578.0 x 105 cells/L) and the lowest in June (37.5 x 105 cells/L). Some hydrographic parameters e.g., surface water temperature, salinity and nutrients (N03-N and P04-P) were recorded and their relationship with the occurrence and abundance of phytoplankton population were also studied. Nutrient concentration was higher during the autumn months, when rain water provided the maximum outflow of rivers discharging into the channel. During the nutrient peak period, the total phytoplankton production was maximum. Bacillariophyceae was the dominant group of phytoplankton throughout the study period except in June and September, when Dinophyceae was dominant. Cyanophyceae was abundant in spring months when temperature began to rise.

Occurrence of Zoothamnium sp. infection in Penaeus monodon (Fabricius, 1798) of the coastal shrimp culture ponds of Cox's Bazar Bangladesh

Penaeus monodon (Fabricius, 1798) is a popular cultivable species and valuable foreign exchange earning item among all the fishery commodities in Bangladesh. At present with semi-intensive and intensive shrimp culture practices, disease is a problem. Protozoan infection, caused by the Zoothamnium sp. is one of the causes of damage in the total production by growth retardation and mortality. No work has yet been done on shrimp disease in Bangladesh. The present account therefore, constitutes the first report on it from the shrimp culture ponds of Cox's Bazar. The present work includes the occurrence and prevalence of protozoan disease, its seasonal variations and level of infestation in different length groups in Penaeus monodon.