Master of Science (MS)
Semester of Degree Completion
Robert U. "Bud" Fischer
This study was conducted to determine egg and hatchling components of the red-eared slider (Trachemys scripta). In addition, energy components transferred from egg to hatchling were used to determine the level of parental investment in embryogenesis and hatchling care. Eggs of the red-eared slider, collected from central Illinois ponds, were obtained by inducing gravid females to lay by an injection of oxytocin. Egg and hatchling lipids were extracted with petroleum ether while egg and hatchling protein content was determined using the micro-Kjeldahl procedure. Eggs averaged 70.7% water by mass, and dry mass of whole eggs and egg yolks averaged 2.4g and 2.1g, respectively. Egg lipids averaged 23.8% of the egg total dry mass and 29.4% of the yolk dry mass, whereas proteins comprised 42.6% of the egg total dry mass and 52.5% of the yolk dry mass. Hatchling somas were comprised of 79.6% water and had a mean dry weight of 0.67g. Hatchling yolk sacs were comprised of 50.3% water and had a mean dry weight of 0.69g. Hatchling somas and yolk sacs averaged 19.0% and 37.4% lipids respectively. Hatchling somas contained 58.9% proteins while yolk sacs contained 44.4%. The amount of non-polar lipids in the egg transferred to hatchling red-eared sliders was used as a measure of parental investment in care (PIC). 67% of the original egg lipids remained in the hatchling turtle in the form of PIC, while only 33% were catabolized during embryogenesis. Thus, the large amount of PIC may play a role in enhancing offspring survival.
Marlen, Michael D., "Parental Investment in the Red-Eared Slider Turtle, Trachemys scripta" (1996). Masters Theses. 1943.