The developing chicken blastoderm can be temporarily maintained in dormancy below physiological zero temperature. However, prolonged preincubation egg storage impairs normal morphological and physiological development of embryos in a potential example of fetal programming (in this case, "embryonic programming"). We investigated how preincubation egg storage conditions (temperature, duration, hy...

The water-rat Nectomys squamipes is mostly important non-human host in schistosomiasis mansoni transmission in Brazil, due to its susceptibility, high abundance and water-contact pattern. During experimental infection of N. squamipes with Schistosoma mansoni, adult worms show phenotypic plasticity. This finding led us to investigate whether biological behavior is also affected. This was assesse...

The effects of soil management systems on root-knot nematode (Meloidogyne incognita) eggs and gall incidence on tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus) following tomato were evaluated. Soil was collected from a replicated field experiment in which six management systems were being assessed for vegetable production. Soil management systems were conventional production, or...

An experiment was conducted to assess how hatching performance is affected by breeder age and egg holding environment during short-term storage. Response variables analyzed were egg weight loss up to 18 d of incubation, viability (hatchability of fertile eggs), embryonic mortality, hatching time, and weight of male and female chicks, at hatching and at the end of incubation. The trials involved...

Inbreeding adversely affects life history traits as well as various other fitness-related traits, but its effect on cognitive traits remains largely unexplored, despite their importance to fitness of many animals under natural conditions. We studied the effects of inbreeding on aversive learning (avoidance of an odour previously associated with mechanical shock) in multiple inbred lines of Dros...

—We evaluated the influence of two broodstock feeding practices on fatty acid composition and viability of eggs in white bass Morone chrysops. The two dietary groups tested were (1) white bass females fed a commercially formulated feed (crude protein, 45%; crude fat, 16%) and (2) white bass females maintained on live food (fathead minnow Pimephales promelas and golden shiners Notemigonus crysol...

BACKGROUND Ability to resist temperature shock is an important component of fitness of insects and other ectotherms. Increased resistance to temperature shock is known to affect life-history traits. Temperature shock is also known to affect reproductive traits such as mating ability and viability of gametes. Therefore selection for increased temperature shock resistance can affect the evolution...

The present study was designed to see whether adding glutathione to tris-citric egg yolk extender improves the quality of buffalo bull spermatozoa stored at 5°C for five days. Semen collected from Nili-Ravi buffalo (Bubalus bubalis) bulls (n = 5) was diluted (37C; 10 x 10 motile spermatozoa per ml) with extender having glutathione (0.0, 0.5, 1.0, 2.0 and 3.0mM). The extended semen was cooled fr...

Information on the molecular basis of resistance and the evolution of resistance is crucial to an understanding of the appearance, spread, and distribution of resistance genes and of the mechanisms of host adaptation in natural populations. One potential important genetic constraint for the evolution of resistance is fitness cost associated with resistance. To determine whether host resistance ...

Fecundity and egg viability of Tribolium castaneum (Herbst) females were significantly (P<0.01) reduced by synthetic pyrethroids and an alkaloid containing insecticide nimbicidine. In control, the average number of eggs laid by each female/day was 12.18. The lowest number of eggs laid by each female/day was noted as 4.38 when combining nimbicidine with two pyrethroids i.e., cypermethrin and del...