Medaka/Chronic ƒÁ-irradiation/Fecundity /Fertility Eggs of the medaka, Oryzias latipes, were irradiated continuously with 137Cs ƒÁ-rays at exposure-rates of 10, 100 and 1000 R/day from the morula stage to hatching. Newly hatched fry were transferred to non-irradiation field. At one year after hatching medaka were tested for their fecundity and fertility. When irradiated females were mated with ...

A closed colony of Lutzomyia longipalpis was established with specimens collected in the Raposa - Serra do Sol indian reservoir, one of the main foci of visceral leishmaniasis in the State of Roraima, Brazil. Biological observations were made on four generations of a L. longipalpis colony with emphasis on productivity. Aspects studied were the number of laid and retained eggs, and the number of...

In the current Iranian poultry industry, antibiotics are the most frequently used additive in feeds to increase the productivity. Regarding the negative effects on human health due to consuming chicken whose feeds contain antibiotics, finding an appropriate alternative is of a great importance. This study aims to find an appropriate and harmless feed additive to increase the quality and quantit...

Kutum, Rutilus frisii kutum, is an commercially important fish in the Caspian Sea. The fish enters the rivers leading to the Caspian Sea for spawning. One of these rivers is Shiroud River. In the artificial propagation process of Kutum, different factors are involved in quality and quantity of female broods eggs and also in the best temperature and migration time for spawning. The influence of ...

Males of many insect species increase the fecundity and/or egg size of their mates through the amount or composition of their nuptial gifts or ejaculate. The genetic bases of such male effects on fecundity or egg size are generally unknown, and thus their ability to evolve remains speculative. Likewise, the genetic relationship between male and female investment into reproduction in dioecious s...

introduction: depending on mode, intensity and length of application, and stage of development, the low-frequency electromagnetic fields (lfes) can induce a wide variety of biological effects in organisms. the chick limb bud is a powerful experimental system for study pattern formation in vertebrate embryo. the aim of this study was to examine the effects of an application lfes (50hz, 50g) on c...