The WorldFish Center and its research partners have recently made efforts to develop genetically improved carp strains. This paper analyses the comparative performance of the genetically improved carp strains on both average and efficient farms in four carp-dominating Asian countries (Bangladesh, India, Thailand and Vietnam). The results show superior performance of improved strains in terms of body weight and survival rate on both average and efficient farms. On an average farm, the improved carp strain gives 15% higher body weight at harvest in India to 36% higher in Bangladesh.
Experiments with fish enclosures were conducted at the Deepwater Rice Farming Systems Research Site at Shuvullah, Mirzapur, Bangladesh. The objective was to study the performance of silver barb (Puntius gonionotus) called Thai sharputi or rajputi in Bangladesh in mono-and-polyculture with grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio), catla (Catla catla) and rohu (Labeo rohita). Each enclosure measured 21 m x 21 m with an approximate net height of 3.5 m.
The length-girth relationships of Javanese carp (Barbodes gonionotus) and hampal carp (Hampala macrolepidota) in the Jatilujur Reservoir, Indonesia were examined. The equations derived from estimating the maximum girth of Javanese carp are G sub(m) = -1.19 + 0.80L, and for the hampal carp, G super(m) = -0.47 + 0.62L. Models relating head girth to total length are also given. The relationship between G sub(m) (maximum girth) of fish caught and gillnet mesh size is also briefly discussed.
The study has conducted the micro level analysis of hatchery operators, fishseed-rearing farmers and carp farmers with respect to their socio-economic characteristics, infrastructural development, husbandry practices and economics returns, based on the survey and on-farm trial data collected by the research partners in six Asian countries, viz. Bangaldesh, China, India, Indonesia, Thailand and Vietnam. The genetically-improved carp strain is economically viable and socially acceptable.
Studies were carried out during May 1997 to January 1998 in Kishoregani district in Bangladesh to investigate the production potential of carp polyculture in combination with Amblypharyngodon mola in seasonal ponds. The preliminary results indicate that A. mola can be successfully cultured in small seasonal ponds in polyculture with carp. This practice can result in an increase in the households' consumption of small fish which have a very high content of calcium, iron and vitamin A.
Assessment and management of risk is needed for sustainable use of genetically modified aquatic organisms (aquatic GMOs). A computer software package for safely conducting research with genetically modified fish and shellfish is described. By answering a series of questions about the organism and the accessible aquatic ecosystem, a researcher or oversight authority can either identify specific risks or conclude that there is a specific reason for safety of the experiment.
This document is part of a series of 5 technical manuals produced by the Challenge Program Project CP34 “Improved fisheries productivity and management in tropical reservoirs”. The reservoirs of India have a combined surface area of 3.25 million hectares (ha), mostly in the tropical zone, which makes them the country's most important inland water resource, with huge untapped potential. The prime objective of cage culture discussed here is to rear fingerlings measuring >100 millimetres (mm) in length, especially carp, for stocking reservoirs.
The findings are presented of a literature survey conducted regarding diseases of tilapia and carp, using ASFA and ICLARM as reference material. Some 536 publications were found and details are given of the addresses of various organizations which may provide further useful information on the subject.
A summary report of the proceedings of the Asian regional conference on carp hatchery and nursery technology held in Manila, Philippines, on 1-3 February 1984, sponsored by the Asian Development Bank and ICLARM.
Following a survey of the important traits of Indian carp broodstock at some southern Indian hatcheries, it was found that the broodstock selection was size selective, exerting strong, negative selection of prematuration growth rate and positive selection on age at first maturation. This meant that the hatchery bred inadvertently slower growing and later maturing individuals. Details are given of approaches to avoid such negative selection and minimize inbreeding.