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.
Although it appears that the first recorded, scientifically oriented culture of tilapia was conducted in Kenya in 1924,of the current 30,000 ponds with a potential annual production of more than 7,000 tons, only 10% are functional producing 500 tons/annum. Tilapia tank culture at Baobab Farm is described in detail. The economics and prospectsof intensive culture in Kenya are considered.
The tilapias are a group of African, freshwater herbivorous fish that care for their young. Their name is derived from an African Bushman word simply mean-ing fish. There are about 70 species, most of them native to western rivers of Africa. Their herbivorous diet, depend¬ing on the species, ranges from coarse vegetation, such as grasses and leaves of water weeds, to unicellular algae and bacteria. This article takes a brief look at a few species of Tilapia and its culture.
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.
The aim of this study was to examine genetic variation in reproductive traits and to estimate correlated responses in such traits to selection for high growth rate in the GIFT strain of Nile tilapia (Oreochromis niloticus).
The main objective of this paper was to report more reliable estimates of the genetic variation and the genotype by test environment interaction for harvest body weight in the GIFT population in the Philippines than could be obtained from the base population by using the data from the five generations following the base population and that covers a wider span of test environments than the later experiments referred to above. Included are also estimates of the genotype by sex interactions for body weight.
The objective of this study is to test the effect of silver carp on water quality and tilapia yield.
Many tilapia (Oreochromis spp.) farmers produce all-male populations because of the superior growth rate of males compared to females. To investigate differences in body weight at harvest of males and females among different tilapia strains, we analyzed data from 62,787 individuals collected from pedigreed breeding programs of O. niloticus (GIFT from Malaysia, the Abbassa line from Egypt, and the Akosombo line from Ghana), O. shiranus (the Bunda College-Domasi selection line), O.
Due to inadequate technical knowledge and training in advanced methods of gradually growing tilapia culture, framers are not getting expected yield. From the very beginning of the CSISA-BD project, WoldFish Center has taken initiative to introduce advanced methods in tilapia culture. To do this, the shortage of skilled trainers and training materials, has, particularly, been realized. Presently, a number of manuals on tilapia culture from Department of Fisheries, Bangladesh Fisheries Research Institute, WorldFish Center and different GOs and NGOs are available.