Details are given of the tilapia hatchery systems used in the Philippines i.e., the "hapa" floating hatcheries and the backyard pond hatcheries, and their applications in Indonesia. Experiments are being conducted in Saguling Reservoir, near Bandung, Indonesia using hapa hatcheries, holding broodstock and growout fingerlings in floating cages. This technology is showing great potential for reaching poor farmers who have little land or capital but adequate water and access to irrigation.
The results are presented of trials conducted whereby cassava peel and mango seed were fed to Nile tilapia (Oreochromis niloticus ) fingerlings. Findings indicate that these products may successfully be used as part of thediets of tilapia fingerlings, although further studies are required in order to determine the optimum proportions.
Genetic improvement through selective breeding has been used for millennia on crops and livestock, but up until the 1980s, little had been done to utilize this process for farmed fish. In response to the inadequate supply of tilapia seed and the deteriorating performance of the fish in many aquaculture systems in Asia, WorldFish and partners began the Genetic Improvement of Farmed Tilapia (GIFT) project to develop a faster-growing strain of Nile tilapia (Oreochromis niloticus) that was suitable for both small-scale and commercial aquaculture.
The effects of ditch size on growth and production of mono-sex tilapia, Oreochromis niloticus in rain fed concurrent rice–fish system were technically and economically evaluated for a period of 4 months. Three different ditch sizes were tried: 5%, 10% and 15% of the total cultivable rice field. It is concluded that rice–fish farming in a rain fed ecosystem of Bangladesh with medium ditch size and stocking density of 5000 ha-1 mono-sex tilapia can achieve better economic return.
A brief account is given of parasites affecting tilapia and carp, covering helminths, bacteria and protozoa. Effects onproduction of culture species are considered in particular, indicating precautions to be taken to reduce possibility ofdisease.
It is proposed that the "recruitment pattern" routine of the ELEFAN II program can be modified to allow, in addition to length-frequency data, the use of "restructured" data files. An example, based on Oreochromis niloticus in Lake Itasy, Madagascar, is given to show that this results in recruitment patterns that have less temporal spread and hence better reflect the actual seasonality of recruitment.
A description is given of the technique used at the Gan Shmuel Fish Breeding Center, in Hadera, Israel, for the commercial mass production of sex inversed Oreochromis hybrids using androgen diets.
The strain by nutrition interaction in body weight and survival rate was examined by testing three genetic groups (Selection and Control lines of the GIFT strain, and Red tilapia) at two levels of protein in the diet (28% and 34%). The GIFT strain of Nile tilapia (Oreochromis niloticus) has been selected for high-breeding values for body weight, whereas the Control was contemporaneously maintained and selected for breeding values of body weight close to the population mean. The Red tilapia (Oreochromis spp) was unselected at the time of the experiment.
Three discrete generations of GIFT fish (Nile tilapia strain, Oreochromis niloticus; a total of 10,065 fish with pedigree and phenotypic information) were tested in pond and cage culture environments to determine genotype by production environment interaction between both environments in Malaysia. Live weight (selected trait), standard length, body depth and width were recorded. A bivariate animal model was used to estimate variance and covariance components, whereby the homologous body traits in pond and cage environments were treated as genetically distinct traits.
Solomon Islands has a population of just over half a million people, most of whom are rural-based subsistence farmers and fishers who rely heavily on fish as their main animal-source food and for income. The nation is one of the Pacific Island Counties and Territories; future shortfalls in fish production are projected to be serious, and government policy identifies inland aquaculture development as one of the options to meet future demand for fish.