Growth and oxygen consumption in embryonic and early postembryonic development of European pond turtle Emys orbicularis (Reptilia: Emydidae)

Abstract

Experiments on developing eggs of European pond turtle ( Emys orbicularis ) demonstrated S-shaped changes in the rate of oxygen consumption and body weight during embryonic development. The rate of oxygen consumption and weight progressively increased within 70 days after hatching. During embryogenesis, the mass-specific rate of oxygen consumption decreased. After hatching, it increased but then decreased to a certain level, which remained constant to the end of the studied period. We observed unidirectional changes in the mass-specific rate of oxygen consumption and specific weight gain during embryonic development and this pattern was maintained after hatching. The coefficients of the allometric relationship between oxygen consumption and body weight were a = 0.33 and k = 0.52 during embryonic development and a = 0.17 and k = 0.89 during postembryonic development. ANIMAL PHYSIOLOGY

Thyroid Hormones Reduce Incubation Period without Developmental or Metabolic Costs in Murray River Short-Necked Turtles (Emydura macquarii)

“…In developing oviparous vertebrates, warmer incubation temperatures accelerate embryogenesis and reduce incubation periods (Birchard and Reiber 1996;Spencer et al 2001;Lin et al 2008;Colbert et al 2010). Oxygen consumption ( _ VO 2 ) and heart rates of embryos are also temperature dependent, partially as a result of accelerated embryogenesis (Birchard and Reiber 1996;Lillywhite et al 1999;Booth et al 2000;Vladimirova et al 2005;Du et al 2010Du et al , 2011. Ultimately, incubation temperature also influences aspects of offspring phenotype, including morphology Du et al 2009Du et al , 2010, performance (Dial 1987;Janzen 1993;Weisrock and Janzen 1999;Booth et al 2004;Nelson et al 2004;Colbert et al 2010), and sex differentiation in species that have temperaturedependent sex determination (Yntema 1968(Yntema , 1978Bull and Vogt 1979;Bull 1985;Christie and Geist 2017).…”

Factors influencing variations of oxygen content in nests of green sea turtles during egg incubation with a comparison of two nesting environments

“…Sea turtle embryos, for example, incubate in beach sand. The nest environment has a profound effect on the survivorship of the embryos (Ackerman, 1981b;Ischer et al, 2009;Maloney et al, 1990;Vladimirova et al, 2005). Habitat factors, temperature, gas partial pressures and water content in the nest, can influence embryonic growth rate (Ackerman, 1981a;Maloney et al, 1990), incubation duration (Ackerman, 1981b;Deeming and Ferguson, 1991;Miller and Limpus, 1980) and hatching as well as emergence success (Glen et al, 2005;Matsuzawa et al, 2002;Mortimer, 1999).…”

Interspecific Variation in Temperature Effects on Embryonic Metabolism and Development in Turtles

“…Therefore, temperature-induced differences in energy utilization could trickle down to affect posthatching condition of offspring by directly or indirectly influencing morphology, physiological performance, or postembryonic energy reserves. The effects of temperature on embryo metabolism have been studied in a variety of reptiles [30][31][32][33][34][35][36]. Patterns in the relationship between temperature and embryo energy expenditure have been fairly consistent.…”