External egg traits like length, breadth, shape index, volume and surface area play important roles for hatching, embryo growth, chick survival. 313 fertilized eggs were collected from three genetic lines of Japanese quail named (white, brown, gray) in four ages (57, 64, 71, 78) days. After collecting the measured by using electronic balance (0.001gm.) sensitivity, caliper vernier (0.01 mm.). T...

Adaptive plasticity at switch points in complex life cycles (e.g., hatching, metamorphosis) is well known, but the evolutionary history of such plasticity is not. Particularly unclear is how a single plastic response (e.g., shifts in hatching timing) evolves to respond to different threats and cues (e.g., abiotic and biotic). We conducted a comparative phylogenetic study of hatching plasticity ...

Fish egg quality is strongly related with the ability of to be fertilized and develop a normal embryo good survival lack abnormalities. Large variations in spawning quantity or impact directly competitiveness sustainability hatcheries, which create an overly large broodstock order satisfy on-growing companies’ demand for undeformed fry. The present study reports, first time relation gilthead se...

Paralomis granulosa Jacquinot is a commercially fished lithodid crab species living in subantarctic and cold-temperate regions of southern South America. Its larval stages (Zoea I, II, Megalopa) are fully lecithotrophic, developing in the complete absence of food from hatching through metamorphosis; first feeding occurs in the first juvenile crab stage. In laboratory rearing experiments conduct...

Traditionally, studies of sexually size-dimorphic birds and mammals report that the larger sex is more sensitive to adverse environmental conditions during ontogeny. However, recent studies in avian species that exhibit moderate size-dimorphism indicate that the smaller sex may be more sensitive to poor rearing conditions. To better understand sex-specific sensitivity in a passerine exhibiting ...

The mammalian embryo is encased in a glycoproteinaceous coat, the zona pellucida (ZP) during preimplantation development. Prior to implantation, the blastocyst must undergo 'hatching' or ZP escape. In hamsters, there is a thinning of the ZP followed by a focal lysis and a complete dissolution of the ZP during blastocyst hatching. Earlier studies from our laboratory have indicated a role for cys...

in the present study, sulfuric acid was used for artemia cysts decapsulation. cysts of artemia franciscana were hatched out in regular manner or following hypochlorite or acid decapsulation. two acid concentrations (1 and 5%), three acid immersion times (10, 30 and 50 min) were used and hatching rates were recorded after 15, 18 and 24 h incubation. hatching rates increased but hatching time dec...

the current study investigated the effect of short-term selection for four week body weight (bw) on performance of divergent lines of japanese quail and their crosses. the mean of bw at hatching time, one, two, three and four week oldand bw at sexual maturity time, age at sexual maturity, number of eggs (from 50 to 100 days old), mean of egg weight, percentage of fertility and hatchability in e...

The emergence of the mammalian blastocysts from their thick glycoprotein investment known as the zona pellucida is an important, but poorly understood, event in embryogenesis. In this paper, we demonstrate that peri-hatching blastocysts generate a considerably high quantum of an active oxyradical species for an extremely short period of time when compared to the pre-hatching (unhatched) and pos...