Macrobrachiurn rosenbergii is one of the widely cultured freshwater prawn species globally. India was the third largest producer of this species in 2007 and its aquaculture production rose to 43,000 metric tons (t) in 2005 froin less than 500 t in 1995. However, since then production has been declining and in 2008-09 it was 12,856 t, a reduction of more than 70% compared to 2005. There are several contributing factors to this decline, such as slow growth rate, poor survival, disease outbreaks, increase in cost of production, and availability of low risk alternative fish species.
There is an increasing demand for fish in the world due to a growing population, better economic situation in some sectors, and greater awareness of health issues in relation to food. Since capture fisheries have stagnated, fish farming has become a very fast growing food production system. In this presentation, the author gives an overview of the technologies that are available for genetic improvement of fish, and briefly discuss their merit in the context of a sustainable development. He also discusses the essential prerequisites for effective dissemination of improved stock to farmers.
Estimates of additive genetic, reciprocal and average heterosis effects were obtained from a three by three complete diallelcross experiment for giant freshwater prawn Macrobrachium rosenbergii. The data were generated in two batches. Three populations were sampled from the states of Gujarat (West), Kerala (South West) and Orissa (East) in India. The two mating batches of diallel crosses were combined in the analysis. A total 4773 animals (2233 in Batch 1 and 2540 in Batch 2) were tagged with VIA (Visible Implant Alpha numeric tags).
A fish aggregating device made of aquatic weeds and grass (Phoom) is used in Loktak lake in the northeastern region of India. It has been used successfully in this very productive fishery for centuries. Today, the fishery itself is under pressure from overexploitation, soil erosion leading to siltation and a hydroelectric project that has blocked the migratory route of the fish that used the lake as a breeding ground.
The expected more interest of marine aquaculture projects in Egypt will increase the demands of marine seed production for a variety of species. The limited and inconsistent availability of wild finfish and shellfish larvae together with an urgent need of establishing selective breeding programs increased the interest in captive reproduction of finfish and shellfish worldwide. The selection of a species suitable for Egyptian marine aquaculture depends primarily on its marketing value, biology and the ability to produce juveniles in significant numbers for commercial production.
A complete diallel cross involving four strains of red tilapia (Oreochromis spp.) from Malaysia, Stirling, Taiwan and Thailand was performed with the aim to establish a foundation population for genetic improvement. The mating involved 16 parental breeders per sex per strain, producing 64 full-sib families in total. Statistical analyses were carried out on data consisting of records from 1280 individuals reared in both freshwater (0 ppt) and saline water (30 ppt) environments.
An early establishment of selective breeding programs on Atlantic salmon has been crucial for the success of developing efficient and sustainable salmon farming in Norway. A national selective breeding program was initiated by AKVAFORSK at the beginning of the 1970s, by collecting fertilized eggs from more than 40 Norwegian river populations. Several private selective breeding programs were also initiated in the 1970s and 1980s. While these private programs were initiated using individual selection (i.e.
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.
The article highlights the aquaculture of marble or sand goby (Oxyeleotris marmoratus) in Malaysia. Topics discussed are: breeding, hatchery and nursery techiques, nutrition, growout techniques, and diseases.
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.