Description |
This report contrasts the morphological changes in the embryos of Japanese quail (Coturnix coturnix japonica) developed under varying environmental conditions. The control group was lost due to the failure of the thermostat of one incubator, introducing the variable of temperature variance. Despite this issue, the experiment was continued using previously published staging markers as a control. Embryos were incubated in two separate containers, divided into one of three groups as follows: (A) varied temperature, rotated twice daily in normoxia ( - 2 1% O2); (B) varied temperature, unrotated in normoxia ( - 2 1% O2); and (C) constant temperature, rotated twice daily in hypoxic conditions ( - 1 5% O2). All developmental stages and morphology were compared to that of documented normal embryonic Japanese quail. Embryos were staged according to previously described defining developmental markers. The embryos were then photographed and measurements of beak length and third toe length were taken. Embryonic samples were taken at days 2 and 4-16. The variation in temperature during incubation showed significant stunting of development on the embryos in group A, which had the highest development rate. The non-rotated eggs, group B, demonstrated high rates of death and no embryonic presence despite egg fertilization. Embryos developed under hypoxic conditions showed stunting and higher rates of death and morphological defect than either group A or B. Exposure to a hypoxic atmosphere or the absence of rotation significantly decreased the embryonic survival rate of C. coturnix japonica, while variation in temperature showed only the stunting of development. |