Metabolic expenditure and feeding performance in hatchling yellow pond turtles (Mauremys mutica) from different incubation temperatures

Abstract

Growth rate variation of organisms might stem from a series of physiological changes induced by different environmental conditions. Hatchling turtles from different incubation temperatures frequently exhibited diverse growth rates. However, the physiological mechanisms underlying this variation remain largely unclear. Here, we investigated the metabolic rate and feeding performance of hatchling Asian yellow pond turtles (Mauremys mutica) from eggs incubated at two different temperatures (26 and 30 °C) to evaluate the role of differences in metabolic expenditure, food intake and digestive efficiency on growth rate variation. Hatchlings from the cooler temperature had a greater growth rate and metabolic rate, tended to eat more food but showed a lower digestive efficiency of energy (DEE) than those from the warmer temperature. Accordingly, the difference in energy acquisition acts as a potential source for growth rate variation of hatchling turtles from different incubation temperatures, and increased energy intake (rather than enhanced digestive efficiency and reduced metabolic expenditure of other physiological processes) might be associated with the higher growth rate of cooler-incubated hatchling M. mutica.