Simple broodstock management to control indirect selection and inbreeding: Indian carp example

Following a survey of the important traits of Indian carp broodstock at some southern Indian hatcheries, it was found that the broodstock selection was size selective, exerting strong, negative selection of prematuration growth rate and positive selection on age at first maturation. This meant that the hatchery bred inadvertently slower growing and later maturing individuals. Details are given of approaches to avoid such negative selection and minimize inbreeding

Biochemical and morphometric approaches to characterize farmed tilapias

Biochemical (electrophoresis and mitochondrial DNA) and morphological analysis are important tools for the characterization of strains. Reference is made to studies conducted in the framework of the Genetic Improvement of Farmed Tilapias project to establish a new base tilapia population for culture purposes, describing the basic concepts of electrophoresis and morphometric analysis

Genetic Improvement of Farmed Tilapias (GIFT) Project: final report, March 1988 to December 1997

Selective breeding, Tilapia culture, Development projects, Research programmes Oreochromis niloticus

RAPD-PCR and Outer Membrane Protein Characterization of Vibrio alginolyticus and Vibrio parahaemolyticus Isolated from Diseased shrimp

Vibrio alginolyticus and V. parahaemolyticus were characterized by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) and profiling of outer membrane proteins (OMP) to the genetic level to enable easier identification of these microorganisms from diseased shrimp (Penaeus monodon) and adopt control measures. Of 20 tested Operon primers (OPC), only OPC5 and OPC18 were used for PCR amlification of 70 isolates representing three strains of each species. OPC5 amplified 1-8 bands with sizes ranging 0.42-2.95 Kb in V. alginolyticus, 5-10 fragments with sizes ranging 0.449-3.55 Kb in V. parahaemolyticus, and one unique common band of 1.34 Kb in both species. When OPC18 was used, one dark band (2.4 Kb) was common to all V. alginolyticus strains and another dark band (1.77 Kb) was common to two strains and the V. alginolyticus ATCC reference strain. One protein band (37.63 kDa) was common to both V. alginolyticus and V. parahaemolyticus and could be used as a diagnostic OMP marker for both species. The simpler and more rapid dot-ELISA and indirect ELISA methods confirmed identification of these pathogenic bacteria

Partial Purification and Characterization of Amylases from the Digestive Tract of the Indian Medium Carp Labeo fimbriatus (Bloch, 1797)

Partial purification of amylases from the digestive tract of the Indian medium carp Labeo fimbriatus through acetone fractionation and Sephadex G-75 gel filtration resulted in 5-fold purification with 29% recovery. Characterization of amylase activity revealed two pH optima at 4.5 and 6.5-7.0. Activity was stable over a wide pH range of 4.0-10.0. Optimum incubation temperature was 25°C. The enzyme lost 80% activity at 50°C within 30 min and was inhibited by 1 mM p-chloromercuri benzoate, ethylene diamine tetra-acetate, and phenyl methyl sulphonyl fluoride. The heavy metal ions Hg++, Cd++, Cu++, Zn++, Fe++, Pb++, Bi++, and Ag+ strongly inhibited enzyme activity whereas Ca++ activated it. Native polyacrylamide gel electrophoresis of the purified amylase fractions revealed four bands, with corresponding molecular weights of 72, 68, 66, and 65 kDa. Amylase activity from L. fimbriatus exhibited linear hydrolysis of starch up to 7% concentration