Fungal infection in the eggs of freshwater fish is well known as a problematic disease. The aim of the present study was to isolate and identify parasitic and saprophytic fungi from affected eggs of rainbow trout at two fish hatchery in Kermanshah province. The sample were inoculated in culture media (SDA,CMA,GPA and stilled water with cotton seed culture) at room temperature (18-24 ° C).17 s...

Rainbow trout, oncorhynchus mykiss is one of the most important cold water fishes in Iran. For successful artificial propagation of rainbow trout, the quality and quantity of brooders and sexual materials are key factors. In the present study, we investigated the age-dependent changes of reproductive efficiency. For this purpose, the brooders were divided into age classes and then three age gro...

Organisms into which heterologous DNA (transgene) has been artificially introduced and integrated in their genomes are called transgenics. Since the mid 1980s, many species of transgenic fish have been produced by introducing desired foreign DNA into unfertilized or newly fertilized eggs by microinjection or electro-poration. More recently, transgenic finfish, shellfish, and crustaceans have al...

An interlaboratory study was conducted to validate a gas chromatographic (GC) method for determination of 21 organochlorine pesticides, 6 pyrethroid pesticides, and 7 polychlorobiphenyl (PCB) congeners in milk, beef fat, fish, and eggs. The method was performed at low contamination levels, which represent relevant contents in food, and is an extension of the European standard (method NF-EN-1528...

1. In a laboratory batch culture experiment, a diapause response of Daphnia magna to a simulated threat of fish predation was tested at various light intensities, which under natural conditions determine potential vulnerability of Daphnia to visual planktivorous fish. 2. Under moderate light intensity (1.4 lmol m s) that allows effective predation by fish, the proportion of females producing do...

In the present research, modification of the zona radiata (ZR) around the molly (Poecilia sphenops, Valencinnes 1846) and bighead carp (Hypophthalmichthys nobilis, Richardson 1845) oocytes and in the zygotes were studied for pre- and post-fertilization stages and its relationship with the reproductive strategy. Light and scanning electron microscopic studies on the histological sections of...