Most animals begin life in eggs, protected and constrained by a capsule, shell, or other barrier. As embryos develop, their needs and abilities change, altering the costs and benefits of encapsulation, and the risks and opportunities of the outside world. When the cost/benefit ratio is better outside the egg, animals should hatch. Adaptive timing of hatching evolves in this context. However, ma...

background & aim: tetranychus urticae koch is one of the most important pests of crops, ornamental and greenhouse plants in the world and, can damage to 900 plant species. resistances to pesticides and acaricides have guided researches to introduce new methods to control t. urticae. botanical pesticides are an important group of natural productions that are usually safer than conventional p...

The study aimed to investigate the effect of in ovo (IO) leptin injection on yolk sac concentration, embryo development, blood lipid metabolism, and biochemical parameters broiler chicks during early post-hatching period. Hatching eggs were weighed placed an incubator with 100 eggs/4 replications/group. groups were: non-injected group (C); 3 injected μl phosphate buffer solution (PBS); 0.5 (L0....

s of papers 17 a significant improvement in growth, feed efficiency, or mortality under conditions of this trial.

Numerous studies emphasize the potential indirect (genetic) benefits of polyandry in animals with resource-free mating systems. In this paper, we examine the potential for these benefits to fuel sexual selection and polyandry in the hermaphroditic ascidian Pyura stolonifera. Individuals were designated either sire (sperm producers) or dam (egg producers) at random and crossed in a North Carolin...

Hatching enzyme is a protease which can degrade the membrane of egg. In this study, a hatching enzyme was purified from starfish (Asterina pectinifera) with 6.34 fold of purification rate, 5.04 % of yield, and 73.87 U/mg of specific activity. The molecular weight of starfish hatching enzyme was 86 kDa, which was reduced to 62 kDa after removal of N-linked oligosaccharides. The optimal pH and te...

We tested the effects of high humidity and submergence on egg hatching of spider mites. In both the high humidity and submergence treatments, many Tetranychus and Panonychus eggs did not hatch until after the hatching peak of the lower humidity or unsubmerged controls. However, after humidity decreased or water was drained, many eggs hatched within 1-3 h. This was observed regardless of when hi...