Literaturdatenbank
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Secor, S. M., & Diamond, J. (1999). Maintenance of digestive performance in the turtles chelydra serpentina, sternotherus odoratus, and trachemys scripta. Copeia, 1999(1), 75–84.
Added by: Admin (14 Aug 2008 22:46:55 UTC) |
| Resource type: Journal Article BibTeX citation key: Secor1999 View all bibliographic details  |
Categories: General Keywords: Chelydra, Chelydra serpentina, Chelydridae, Emydidae, Ernährung = nutrition, Kinosternidae, Pseudemys, Schildkröten = turtles + tortoises, Sternotherus, Sternotherus odoratus, Trachemys, Trachemys scripta Creators: Diamond, Secor Collection: Copeia |
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| Abstract |
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Pseudemys In our continued investigation of the adaptive interplay between feeding ecology and digestive physiology, we measured postfeeding responses of juvenile Chelydra serpentina, adult Sternotherus odoratus, and subadult Trachemys scripta, three aquatic turtle species that feed at frequent intervals and consume a catholic diet of plants and animals. In this study, we measured O2 consumption rates from fasting and digesting individuals and compared intestinal nutrient uptake rates and organ masses of turtles fasted for one month with turtles sacrificed one day after the ingestion of a meal equivalent to 5-11% of body mass. O2 consumption during digestion peaked at rates 3.4, 2.1, and 2.7 times fasting values, respectively, for C. serpentina, S. odoratus, and T. scripta-factors much smaller than those documented previously for reptile species that normally consume large meals at long intervals. None of the turtle species experienced significant postfeeding changes in intestinal uptake of amino acids or D-glucose. Ratios of amino acid uptake rates to D-glucose uptake rates were much greater than 1.0 for each species, either fasted or fed, a finding characteristic of other carnivores as well. Total intestinal capacity to transport the amino acids L-leucine and L-proline and the sugar D-glucose did not change with feeding for any of the turtle species. None of the species experienced significant differences in intestinal mass or enterocyte morphology between fasted and fed individuals. Chelydra serpentina and T. scripta experienced no significant postfeeding changes in organ masses, and the only changes for S. odoratus were 59% and 42% increases in stomach wet and dry masses, respectively, upon feeding. Thus, juvenile C. serpentina, adult S. odoratus, and subadult T. scripta maintain the functional and morphological integrity of their guts during fasting and exhibit only modest metabolic responses to feeding. We hypothesize that these are adaptive traits characteristic of species that frequently consume and digest small meals.
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