This study presents results of two generations of selection (G1 and G2) for growth of Nile tilapia. The selection environment consisted of earthen ponds which were fertilized daily with 50 kg dry matter (dm)/ha chicken manure. No supplementary feeds were provided. In total, 6429 fully pedigreed experimental fish were included in the analysis. Survival till harvest was highly variable ranging from 35% to 77% and was affected by initial weight, pond, and age effects.
The paper presents a brief summary of the available methods to determine connectivity using genetic markers and two examples where they have been applied in Southeast Asia. Recommendations for the more efficient conduct of the research based on the experiences from these projects are presented.
Genetic and phenotypic parameter estimates for tagging and harvest body weights were obtained from the F1 base (377 offspring of 59 full-sib families), F2 (1241 offspring of 52 full- and 33 half-sib families) and F3 (1052 offspring of 55 full- and 25 half-sib families) generations of Oreochromis shiranus. The fish were reared in earthen ponds at three different test environments inMalawi, which were high altitude (Chisitu), medium altitude (Domasi) and low altitude (Kasinthula) fish farms.
In comparison to the rest of the world, aquaculture in Africa is fairly insignificant. The continent as a whole contributed a mere 0.9 per cent (404 571 t) to the total world aquaculture production in 2000. The African continent, however, exhibits considerable potential in terms of land and water and in regard to inland, coastal and offshore resources. Genetic improvement of tilapias has a role to play in order to increase aquaculture production.
The present study is based on data recorded from fish of the third generation of the GIFT project (Genetic Improvement of Farmed Tilapias). The objective of the study was to compose a synthetic base population of Nile tilapia for further selective breeding, and to estimate phenotypic and genetic parameters in that population.
ADB RETA 5711 on the Genetic Improvement of Carp Species in Asia showed that the growth performance of carps, the most cultured fish in the world, could be improved by 10% per generation of selection, based on the preliminary studies of 4 carp species in the 6 Developing Member Countries (DMCs) participating (Bangladesh, the People's Republic of China, India, Indonesia, Thailand and Vietnam).
This book contains six chapters 1)Introduction 2) Status of carp genetic resources 3)Brood stock management and artificial breeding of carp species in hatcheries 4)A breeding plan for cultured minor carp species 5)A breeding plan for cultured major carp species 6)Breeding and conservation of endangered carp species
Report of a 1992 workshop. Includes discussion papers on population genetics, broodstock establishment, preservation of biodiversity, hatchery procedures, and identifying strains; country papers from Australia, Fiji, Palau, Philippines and the Solomon Islands; discussion sessions and recommendations.
As compared to crops and livestock, the genetic enhancement of fish is in its infancy. While significant progress has been achieved in the genetic improvement of temperate fish such as salmonids, no efforts were made until the late 1980s for the genetic improvement of tropical finfish, which account for about 90 percent of global aquaculture production.