I. G. Vladimirova

The Relation of Energy Metabolism and Body Weight in Bivalves (Mollusca: Bivalvia)

On the basis of experimental and published data, the interspecific and intraspecific (ontogenetic) dependence of energy metabolism on body weight in bivalves was calculated. Changes in the parameters of intraspecific allometric dependence under the effect of environmental factors were analyzed. The rate of comparable standard metabolism (coefficient a at k = 0.76) was shown to vary in different taxonomic and zoogeographic groups of bivalves.

Standard Metabolic Rate in Gastropoda Class

Abstarct—The relationship between oxygen consumption and soft tissue weight in the Gastropoda class (according to the obtained and published data) is expressed by the equation with coefficientsa = 0.71 and k = 0.78. Prosobranch and pulmonate snails have similar levels of oxygen consumption. Opisthobranch snails have higher oxygen consumption. No relationship has been revealed between the metabolic rate (coefficient a) and climatic zone of the gastropod habitat.

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

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.

Effect of Temperature on the Rate of Oxygen Consumption during the Second Half of Embryonic and Early Postembryonic Development of European Pond Turtle Emys orbicularis (Reptilia: Emydidae)

Oxygen consumption by eggs of European pond turtle was determined at two constant incubation temperatures of 25 and 28°C during the second half of embryogenesis. During development at both temperatures, the rate of oxygen consumption initially increased to remain constant during the last quarter of embryogenesis. The difference between the rates of oxygen consumption at these temperatures decreased during the studied period. The coefficient Q10 for the rate of oxygen consumption decreased from 9 to 1.7. At an incubation temperature of 28°C, the changes in the rate of oxygen consumption in response to a short-term temperature decrease to 25°C or increase to 30°C depended on the developmental stage and were most pronounced at the beginning of the studied period. During late embryonic and first 2.5 months of postembryonic development, the rate of oxygen consumption did not significantly differ after such temperature changes. The regulatory mechanisms formed during embryonic development are proposed to maintain the level of oxygen consumption during temperature changes.

Specific Growth Rate and the Level of Energy Metabolism in the Ontogeny of Axolotl, Ambystoma mexicanum(Amphibia: Ambystomatidae)

Concordant changes in the level of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

Respiration Rate and Species-Specific Lifespan in Freshwater Bivalves of Margaritiferidae and Unionidae Families

We studied changes in the respiration rate in five species of freshwater bivalves as a function of animal age and size. The species-specific lifespan was calculated on the basis of the obtained data: Rubners constant (Ru) and lifespan at standard temperature 20°C (T20). The longest and shortest lifespan among the studied mollusks was specific for the pearl mussel Margaritifera margaritifera(Ru= 37 kJ and T20= 36 years) and the freshwater mussel Anodonta anatina(Ru= 8 kJ and T20= 8 years), respectively.

Effect of hypoxia on amnion rhythmic contractions and heart rate in the embryonic European pond turtle Emys orbicularis (Reptilia: Emydidae)

The effect of acute hypoxia (10% O2 for 30 min) on the rate of amnion rhythmic contractions and heart rate (HR) was studied in two age groups of European pond turtle (Emys orbicularis) embryos, on days 19–27 and 37–43 of incubation (30–40 and 60–70% of the period until hatching). Under the control conditions, the two age groups of embryos did not differ from each other in either parameter. Hypoxia did not affect significantly the amnion contraction frequency but decreased the HR. The time course of the HR during hypoxia depended on the embryo age. The mean HR in the first group of embryos was 8% decreased by minutes 10–14 of hypoxia and did not change afterwards; in the second group, it was 18% decreased by minutes 3–7 and then partly or completely restored before the end of hypoxic exposure. It has been assumed that the capacity of European pond turtle embryos for restoring the HR when exposed to acute hypoxia during the second half of embryogenesis is related to the development of neurohumoral control mechanisms.

[Dynamics of body mass and oxygen consumption in the ontogeny of the Spanish ribbed newt (Pleurodeles waltl): 2. Larval stage].

The correlation between characteristics of growth and energy metabolism during the larval stage of development of the Spanish ribbed newt (Pleurodeles waltl) has been studied. During this period, its body mass is found to increase 140 times and the oxygen consumption rate, 77 times. The highest rate of specific body mass increase and oxygen consumption rate are noted in the early larval stage. Later, these characteristics decrease except for a brief period before completion of metamorphosis when the rate specific body mass increase rises. Comparison of the studied characteristics allows us to note a similar pattern in changes of the specific growth rate and the oxygen consumption rate during the premetamorphic development of the Spanish ribbed newt.

Dynamics of body mass and oxygen consumption in the ribbed newt Pleurodeles waltl ontogenesis: 1. Endotrophic development

The correlation between parameters of growth and energy metabolism in the example of embryonic and larval development of the ribbed newt Pleurodeles waltl has been studied. The wet body mass increases five times during this period due to water absorption by developing tissues and the yolk, and the dry mass decreases 1.18 times. The highest mass-specific growth rate and mass-specific rate of oxygen consumption of developing tissues was noticed at the 33rd stage of embryogenesis (13th–14th day of development). These indexes decreased after the hatching, but increased after larvae switched to external nutrition. Comparison of the studied parameters has identified a similar features in alteration of mass-specific growth rate, mass-specific rate of oxygen consumption, and watering of developing tissues in early development of the ribbed newt.

The dynamics of mass growth and oxygen consumption in ontogenesis of the newt Pleurodeles waltl: 3. The postlarval period

The relationship between animal growth and oxygen consumption was studied by the example of the postlarval period in ontogenesis of the newt Pleurodeles waltl. These parameters increased during the first 1.5 years after metamorphosis and then did not change. Gender differences were found for the body mass, growth rate, and rate of oxygen consumption, which in males were less than in females. The mass-specific rates of oxygen consumption in males and females were the same. The relationship between the body mass and the rate of oxygen consumption in immature and mature newts can be expressed by a common allometric equation.