Relative performance of two Nile tilapia (Oreochromis niloticus Linnaeus) strains in Egypt: The Abbassa selection line and the Kafr El Sheikh commercial strain

The Abbassa selection line (developed by selective breeding) and the Kafr El Sheikh commercial strain (widely used in Egypt), both Oreochromis niloticus, were compared at two stocking densities (two and four fish m-2). Harvest weight, length, depth, width and head length were recorded. The Abbassa line showed a superior harvest weight (28 per cent) over the Kafr El Sheikh strain. Males were heavier than females, but the between-sex difference was greater in the commercial than in the Abbassa line (39 and 31 per cent respectively).

Indirect genetic effects and inbreeding: Consequences of BLUP selection for socially affected traits on rate of inbreeding

Social interactions often occur among living organisms, including aquatic animals. There is empirical evidence showing that social interactions may genetically affect phenotypes of individuals and their group mates. In this context, the heritable effect of an individual on the phenotype of another individual is known as an Indirect Genetic Effect (IGE). Selection for socially affected traits may increase response to artificial selection, but also affect rate of inbreeding.

Growth and survival rate of three genetic groups fed 28% and 34% protein 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.

Genetic improvement of farmed tilapias: Genetic parameters for body weight at harvest in Nile tilapia (Oreochromis niloticus) during five generations of testing in multiple environments

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.

Distribution, migrations and breeding of Hilsa (Tenualosa ilisha) in the Ayeyarwady system in Myanmar

Hilsa (Tenualosa ilisha) is a major fishery resource in the Bay of Bengal. In order to ensure the sustainability of this resource, through effective management measures, information is required on its distribution patterns, migration routes and breeding sites. This study fills these knowledge gaps in Myanmar’s Ayeyarwady Delta. The findings are based on systematic gathering of local ecological knowledge among experienced fishers in thirty-two sites.

A comparison of communal and separate rearing of families in selective breeding of common carp (Cyprinus carpio): Responses to selection

The genetic response in growth traits in a selection program for increased harvest weight in a common carp population in Vietnam is reported. A base population (G0) was established from six carp stocks using single pair mating. Selection was based on high breeding values for body weight at harvest, with a corresponding control group selected on average breeding values of the population.

Breeding marine aquarium animals: the anemonefish

A brief account is given of experiments undertaken regarding the breeding of anemonefish (Amphiprion ), a species popular among marine aquarists. Findings indicate these fish to be good candidates for reproductive physiology research; they produce large eggs and larvae, spawn frequently in captivity, are hardly to handle and can be maintained in small tanks. Future prospects for the culture of tropical marine aquarium fish are believed to be good.

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