This case study looks at changing livelihood strategies of the coastal population in Soc Trang Province in the Mekong Delta, Vietnam, and their impacts on natural resources. It provides an opportunity not only to document the impact of shrimp farming on coastal livelihood but also to better understand the link between brackish water aquaculture development and natural resource use. The approach includes a socio-economic survey in six villages of the province focusing on risk strategies and livelihood diversification.
A study of chemoreception in relation to feeding and other factors involved showed that feeding behavior in shrimps can be triggered by chemical stimuli. However, Penaeus indicus and Metapenaeus dobsoni differ significantly in their chemotactic response to different stimuli.
The aims of this project were to develop large scale breeding and rearing methods for sandfish (Holothuria scabra) for commercial culture and/or restocking. Wild collected sea cucumbers were initially difficult to spawn, but after a period in earthen ponds or seabed pens could be induced year-round, using temperature changes, emersion, treatment of water with UV light, and addition of dry phytoplankton. Numerous batches of larvae were reared to settlement and to larger sizes using simple hatchery methods.
Food conversion efficiency and growth in the white shrimp Penaeus indicus fed with decomposed mangrove leaves of Avicennia marina and A. officinalis were monitored under laboratory conditions. It was observed that test animals fed with the decomposed leaves of A. marina had higher assimilation efficiency (87.96%), gross growth efficiency (10.82%), net growth efficiency (12.3%) and relative growth rate (0.0603 g/day) than those fed with A. officinalis. The relatively higher growth registered in the animals fed with decomposed leaves of A.
Inhibitory activity of a marine pigmented bacterium - Alteromonas sp. - isolated from Penaeus monodon Fabricius larva against pathogenic and environmental isolates of Vibrio harveyi was studied. All the isolates were inhibited to varying degrees by Alteromonas sp. in vitro. The antibacterial substance produced by the Alteromonas sp. was soluble in organic solvent and closely bound to the external surface of bacterial cells. The antibacterial Alteromonas sp., when allowed to colonize on shrimp larvae, suppressed the activity of V. harveyi M3 and reduced mortality of P.
The white spot viral disease in penaeid shrimp affects the development of the global shrimp industry. This paper reviews the viruses that cause the disease, the transmission of the virus, diagnosis and preventive measures.
This study was undertaken to determine the effect of nutritional management of broodstock of Penaeus monodon on growth and maturation. Test specimens were obtained from a grow-out pond before attainment of maturity and were reared in hatchery tanks. Four types of dietary treatments (M1–M4) were given to separate batches that were run in duplicate. Feeding trials continued for five months. A diet with live bloodworm, bioencapsulated to contain tricalcic phosphate as its major component, was found to be the most efficient.
A trophic model of the coastal ecosystem in the waters of Bangladesh, Bay of Bengal (from the shoreline to 150 m depth) is presented. The model consists of 15 ecological groups. The biomasses of the groups (particularly the demersal species) were estimated from demersal trawl surveys conducted in the area between 1984 and 1986. The model estimated that the average trophic level of the trawl fishery catch was 2.7 in these years.
Vibriosis caused by opportunistic and secondary bacterial pathogens is still a serious disease problem in aquaculture of the black tiger shrimp Penaeus monodon. Attempts were made for controlling shrimp bacterial disease using Marine Secondary Metabolites (MSMs). Findings indicated that the MSMs of seaweed Ulva fasciata and Dendrilla nigra are effective for controlling shrimp bacterial pathogens.
This article gives an overview of the shrimp farming scene in Bangladesh in the 80s.