Chemical Composition of the Eggs of the Freshwater Turtle Phrynops hilarii (Chelidae: Testudines)

PRIETO, Y.A.; MANZANO, A. S.; ROZYCKI, V.; BERNARDI, C.

Herpetological conservation and Biology

Herpetological Conservation and Biology

Lugar: Fresno; Año: 2019 vol. 14 p. 393 - 401

1931-7603

At oviposition, amniote eggs contain all the nutrients required for complete neonate tissue development. For reptiles and birds, the egg yolk is the main embryonic energy source and is composed predominantly by proteins and lipids, while also providing essential inorganic ions including calcium (Ca), potassium (K) and magnesium (Mg),and trace elements such as zinc (Z) and iron (Fe). Despite the fact that Phrynops hilarii is one of the most representative and widely distributed turtle species in Argentina, there are very few studies regarding its reproductive biology. The objectives of this work were to 1) describe the morphological characteristics of Phrynops hilarii eggs, specifically egg and yolk size; 2) determine the relative proportions of egg yolk components (water, ash, lipids, proteins, and minerals); and 3) examine the relationships between egg size, yolk size and yolk components. A total of 171 eggs were collected from 11 individual nests during the 2012 March-April reproductive season. One egg per clutch (n=11) was analyzed to determine the egg yolk chemical composition.Yolks were composed of 58.3% water, while the dry component was 2.7% ash, 24.9% lipids and 56.7% protein. The most abundant of the measured macromineral detected was K (0.63%) and the most abundant trace mineral was Mg (0.13%). No associations between egg measurements and components were found, but there were many significant correlations between egg components. Data collected for this study are important to begin to understand the roles of different nutrients in embryonic development and to further explore maternal investment patterns in Phrynops hilarii.