The present study examined the variation in survival, proportion of male morphotypes, female and male proportion, female reproductive status and tag losses in nine crosses from a complete (3 × 3) diallel mating of three populations of Macrobrachium rosenbergii in India. The populations originated from Gujarat (north-west), Kerala (south-west) and Odisha (east), representing different agro-ecological regions in India. Progeny from 60 families (4773 juveniles) were individually tagged and reared for 16–17 weeks in earthen ponds. Binary logistic regression was used to analyse the data.
The development of a saline tolerant tilapia strain able to grow fast is of importance in the Philippines, where 240 000 ha of brackish water ponds are available. To this end, founder hybridization between Oreochromis niloticus (with favorable growth traits) and O. mossambicus (with favorable salinity tolerance traits) was performed and followed by backcrossing with O. mossambicus to develop a strain highly tolerant to saline environments. Genetic selection for growth performance was subsequently conducted.
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).
One of the major steps in the innate immune response of shrimp includes the activation of serine proteinases of the pro-phenoloxidase pathway by the prophenoloxidase activation enzyme (PPAF). In this study, the cDNA encoding a serine proteinase homologue (SPH) with prophenoloxidase activating activity of Penaeus monodon (PmPPAF) was cloned and characterized.
The aims of the present study were to develop non-lethal methods to identify individual fish larvae and post-larvae before tagging and accurately follow their growth characteristics. European sea bass (Dicentrarchus labrax) was used as a model species at four different ages ranging from 71 to 100 days post fertilization (dpf).
When different strains or breeds of a particular species are available, the best choice is seldom immediately obvious for producers. Scientists are also interested in the relative performance of different strains because it provides a basis for recommendations to producers and it often stimulates the conduct of work aimed at unraveling the underlying biological mechanisms involved in the expression of such differences. Hence, strain or breed comparisons of some sort are frequently conducted.
Benefits derived from selective breeding have been demonstrated in livestock and in some fish species, but by contrast, there have been few systematic selection programs reported for shrimps. Improving growth rate has been identified as the most important trait in the breeding objective for cultured shrimp species. In the present study we analyzed a four generation data set from a fully pedigreed selective breeding program for giant freshwater prawn (GFP in Vietnam. We estimated phenotypic and genetic parameters for body and carcass weight traits.
This study investigates the genetic structure and phylogeography of a broadcast spawning bivalve mollusc, Pinctada maxima, throughout the Indo-West Pacific and northern Australia. DNA sequence variation of the mitochondrial cytochrome oxidase subunit I (COI) gene was analysed in 367 individuals sampled from nine populations across the Indo-West Pacific.
This viewpoint paper explores the potential of genomics technology to provide accurate, rapid, and cost efficient observations of the marine environment. The use of such approaches in next generation marine monitoring programs will help achieve the goals of marine legislation implemented world-wide. Genomic methods can yield faster results from monitoring, easier and more reliable taxonomic identification, as well as quicker and better assessment of the environmental status of marine waters.
Genetic parameters and selection responses were obtained for harvest body weight of blue tilapia (Oreochromis aureus) from data collected over three generations in a selected population. A total of 18 194 records representing 186 sires and 201 dams were used in the analysis. Within generation heritability estimates for harvest body weight ranged from 0.18 to 0.58. When data from more than one generation were included in the analysis, heritability estimates became more stable (0.33–0.40) and it was 0.33 when all data were included in the analysis.