Specific dynamic action(SDA), the energy expended on all physiological processes that is associated with meal digestion and absorption, is strongly affected by food type. Effects of formulated diet(FMD), macroalgae(AL...Specific dynamic action(SDA), the energy expended on all physiological processes that is associated with meal digestion and absorption, is strongly affected by food type. Effects of formulated diet(FMD), macroalgae(ALG) and sea mud(SMD) diets on the postprandial metabolic response of the green type and the red type of sea cucumber(Apostichopus japonicus) were studied in order to understand their feeding physiology. Food offered to A. japonicus was different in protein, lipid content and energy but not in meal mass. SDA of A. japonicus resulted in a 1.3–2.7 folds of increase in oxygen consumption that can persist for up to 4.8–31.7 h after digesting three different diets. In a given type of sea cucumber, the magnitude of SDA was the highest when fed with FMD, medium with ALG, and the lowest with SMD, which is probably due to the differences in diet components and protein contents. The red type sea cucumber showed greater SDA magnitude than the green type with each diet treatment, which might result from the difference in factorial scope between the two types of sea cucumber. However, the smallest magnitude or even no difference was observed between the two types of A. japonicus in SMD group, perhaps owing to the poor nutrition and digestion of sea mud.展开更多
Foraging mode （ambush vs. active） profoundly affects many aspects of organismal biology, including metabolic rates and their relationship with food intake. Previous studies on snakes suggest that ambushers tend to h...Foraging mode （ambush vs. active） profoundly affects many aspects of organismal biology, including metabolic rates and their relationship with food intake. Previous studies on snakes suggest that ambushers tend to have lower standard metabolic rates （SMR） and higher energetic costs of digestion and assimilation of prey （specific dynamic action, or SDA） than do active foragers. However, phylogenetic considerations may be at least partly responsible for such patterns, as foraging mode is strongly conserved evolutionarily and most SDA studies have focused on species from only two lineages of ambush foragers （pythonid and viperid snakes） and one lineage of active foragers （colubrid snakes）. We sought to deconfound the effects of phylogeny and foraging mode, investigating SMR and SDA in two closely related pygopodid lizards, the common scaly-foot Pygopus lepidopo- dus （active forager） and Burton＇s legless lizard Lialis burtonis （ambush forager）. Consistent with the pattern seen in snakes, L. burtonis exhibits a significantly lower SMR and a higher SDA than does P lepidopodus. The magnitude of SDA in L. burtonis is comparable to that of some pythons and vipers, providing yet more evidence for the remarkable convergence between this species and ambush-foraging snakes [Current Zoology 59 （5）： 618-625, 2013].展开更多
基金the National Key Technologies Research and Development Program of China (No. 2011BAD13B03)Foundation of Liaoning Educational Committee (No. L2014254)
文摘Specific dynamic action(SDA), the energy expended on all physiological processes that is associated with meal digestion and absorption, is strongly affected by food type. Effects of formulated diet(FMD), macroalgae(ALG) and sea mud(SMD) diets on the postprandial metabolic response of the green type and the red type of sea cucumber(Apostichopus japonicus) were studied in order to understand their feeding physiology. Food offered to A. japonicus was different in protein, lipid content and energy but not in meal mass. SDA of A. japonicus resulted in a 1.3–2.7 folds of increase in oxygen consumption that can persist for up to 4.8–31.7 h after digesting three different diets. In a given type of sea cucumber, the magnitude of SDA was the highest when fed with FMD, medium with ALG, and the lowest with SMD, which is probably due to the differences in diet components and protein contents. The red type sea cucumber showed greater SDA magnitude than the green type with each diet treatment, which might result from the difference in factorial scope between the two types of sea cucumber. However, the smallest magnitude or even no difference was observed between the two types of A. japonicus in SMD group, perhaps owing to the poor nutrition and digestion of sea mud.
文摘Foraging mode （ambush vs. active） profoundly affects many aspects of organismal biology, including metabolic rates and their relationship with food intake. Previous studies on snakes suggest that ambushers tend to have lower standard metabolic rates （SMR） and higher energetic costs of digestion and assimilation of prey （specific dynamic action, or SDA） than do active foragers. However, phylogenetic considerations may be at least partly responsible for such patterns, as foraging mode is strongly conserved evolutionarily and most SDA studies have focused on species from only two lineages of ambush foragers （pythonid and viperid snakes） and one lineage of active foragers （colubrid snakes）. We sought to deconfound the effects of phylogeny and foraging mode, investigating SMR and SDA in two closely related pygopodid lizards, the common scaly-foot Pygopus lepidopo- dus （active forager） and Burton＇s legless lizard Lialis burtonis （ambush forager）. Consistent with the pattern seen in snakes, L. burtonis exhibits a significantly lower SMR and a higher SDA than does P lepidopodus. The magnitude of SDA in L. burtonis is comparable to that of some pythons and vipers, providing yet more evidence for the remarkable convergence between this species and ambush-foraging snakes [Current Zoology 59 （5）： 618-625, 2013].
