Energetic costs of digestion in Australian crocodiles
C. M. Gienger A E F , Christopher R. Tracy A B , Matthew L. Brien A C , S. Charlie Manolis C , Grahame J. W. Webb A C , Roger S. Seymour D and Keith A. Christian A
+ Author Affiliations
- Author Affiliations
A Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT 0909, Australia.
B Department of Zoology, University of Melbourne, Parkville, Vic. 3010, Australia.
C Wildlife Management International and Crocodylus Park, Berrimah, NT 0828, Australia.
D School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia.
E Current address: Department of Biology and Center of Excellence for Field Biology, Austin Peay State University, Clarksville, TN 37044, USA.
F Corresponding author. Email: giengerc@apsu.edu
Australian Journal of Zoology 59(6) 416-421 https://doi.org/10.1071/ZO12018
Submitted: 10 February 2012 Accepted: 21 May 2012 Published: 1 June 2012
Abstract
We measured standard metabolic rate (SMR) and the metabolic response to feeding in the Australian crocodiles, Crocodylus porosus and C. johnsoni. Both species exhibit a response that is characterised by rapidly increasing metabolism that peaks within 24 h of feeding, a postfeeding metabolic peak (peak 
O2) of 1.4–2.0 times SMR, and a return to baseline metabolism within 3–4 days after feeding. Postfeeding metabolism does not significantly differ between species, and crocodiles fed intact meals have higher total digestive costs (specific dynamic action; SDA) than those fed homogenised meals. Across a more than 100-fold range of body size (0.190 to 25.96 kg body mass), SMR, peak O2, and SDA all scale with body mass to an exponent of 0.85. Hatchling (≤1 year old) C. porosus have unexpectedly high rates of resting metabolism, and this likely reflects the substantial energetic demands that accompany the rapid growth of young crocodilians.
References
Andrade, D. V., Cruz-Neto, A. P., Abe, A. S., and Wang, T. (2005). Specific dynamic action in ecothermic vertebrates: a review of the determinants of postprandial metabolic response in fishes, amphibians, and reptiles. In ‘Physiological and Ecological Adaptations to Feeding in Vertebrates’. (Eds J. M. Stark and T. Wang.) pp. 305–324. (Science Publishers: Enfield.)Beaupre, S. J., and Zaidan, F. (2001). Scaling of CO2 production in the timber rattlesnake (Crotalus horridus), with comments on cost of growth in neonates and comparative patterns. Physiological and Biochemical Zoology 74, 757–768.
| Scaling of CO2 production in the timber rattlesnake (Crotalus horridus), with comments on cost of growth in neonates and comparative patterns.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3Mvnt1emug%3D%3D&md5=7b33064473f935981f57a5def9241657CAS |
Bedford, G. S., and Christian, K. A. (2000). Digestive efficiency in some Australian pythons. Copeia 2000, 829–834.
| Digestive efficiency in some Australian pythons.Crossref | GoogleScholarGoogle Scholar |
Bedford, G. S., and Christian, K. A. (2001). Metabolic response to feeding and fasting in the water python (Liasis fuscus). Australian Journal of Zoology 49, 379–387.
| Metabolic response to feeding and fasting in the water python (Liasis fuscus).Crossref | GoogleScholarGoogle Scholar |
Boback, S. M., Cox, C. L., Ott, B. D., Carmody, R., Wrangham, R. W., and Secor, S. M. (2007). Cooking and grinding reduces the cost of meat digestion. Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology 148, 651–656.
| Cooking and grinding reduces the cost of meat digestion.Crossref | GoogleScholarGoogle Scholar |
Christel, C. M., DeNardo, D. F., and Secor, S. M. (2007). Metabolic and digestive response to food ingestion in a binge-feeding lizard, the Gila monster (Heloderma suspectum). The Journal of Experimental Biology 210, 3430–3439.
| Metabolic and digestive response to food ingestion in a binge-feeding lizard, the Gila monster (Heloderma suspectum).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtlOitb3K&md5=b10bc2a2b4f13f7e68084bb2b00c9558CAS |
Coulson, R. A., and Hernandez, T. (1979). Increase in metabolic rate of the alligator fed proteins or amino acids. The Journal of Nutrition 109, 538–550.
| 1:CAS:528:DyaE1MXktVChtLo%3D&md5=637cab1ec0f20d049335d98a32caff61CAS |
Coulson, R. A., and Hernandez, T. (1983). Alligator metabolism studies on chemical reactions in vivo. Comparative Biochemistry and Physiology 74, 1–175.
| Alligator metabolism studies on chemical reactions in vivo.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL3s7ls1KgtQ%3D%3D&md5=e00bb3c35ae8277d6ef09cb64ad3fcfaCAS |
Davenport, J., Grove, D. J., Cannon, J., Ellis, T. R., and Stables, R. (1990). Food capture, appetite, digestion rate and efficiency in hatchling and juvenile Crocodylus porosus. Journal of Zoology 220, 569–592.
| Food capture, appetite, digestion rate and efficiency in hatchling and juvenile Crocodylus porosus.Crossref | GoogleScholarGoogle Scholar |
Frappell, P. B., Blevin, H. A., and Baudinette, R. V. (1989). Understanding respirometry chambers: what goes in must come out. Journal of Theoretical Biology 138, 479–494.
| Understanding respirometry chambers: what goes in must come out.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3c%2FotV2jsw%3D%3D&md5=7af67a975c4d4ae1c38a979eade55259CAS |
Garnett, S. T. (1988). Digestion, assimilation and metabolism of captive estuarine crocodiles, Crocodylus porosus. Comparative Biochemistry and Physiology A – Physiology 90, 23–29.
| 1:STN:280:DyaL1c3psFyitw%3D%3D&md5=1cc226e76a843e1883a67c49a7f6109bCAS |
Gatten, R. E. (1980). Metabolic rates of fasting and recently fed spectacled caimans (Caiman crocodilus). Herpetologica 36, 361–364.
Gessaman, J. A., and Nagy, K. A. (1988). Energy metabolism: errors in gas-exchange conversion factors. Physiological Zoology 61, 507–513.
Grigg, G. C. (1978). Metabolic rate, Q10 and respiratory quotient (RQ) in Crocodylus porosus, and some generalizations about low RQ in reptiles. Physiological Zoology 51, 354–360.
Hailey, A. (1998). The specific dynamic action of the omnivorous tortoise Kinixys spekii in relation to diet, feeding pattern, and gut passage. Physiological Zoology 71, 57–66.
| The specific dynamic action of the omnivorous tortoise Kinixys spekii in relation to diet, feeding pattern, and gut passage.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK1c7jt1Wmtw%3D%3D&md5=7a086fdc6439ffd4653b5f4caf029c4cCAS |
Hayes, J. P. (2001). Mass-specific and whole-animal metabolism are not the same concept. Physiological and Biochemical Zoology 74, 147–150.
| Mass-specific and whole-animal metabolism are not the same concept.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M3osF2msg%3D%3D&md5=5a3e233a1b8b10192d21adcf9771ea5aCAS |
Kercheval, D. R., and Little, P. L. (1990). Comparative growth rates of young alligators utilizing rations of plant and/or animal origin. In ‘Proceedings of the 10th Working Meeting, IUCN Crocodile Specialist Group, Gainesville, FL’. pp. 286–312.
Lighton, J. R. B. (2008). ‘Measuring Metabolic Rates: A Manual for Scientists.’ (Oxford University Press: Oxford.)
McCue, M. D. (2006). Specific dynamic action: a century of investigation. Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology 144, 381–394.
| Specific dynamic action: a century of investigation.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28vgslOgug%3D%3D&md5=eeb6793a1511cc6821f2e5e9ddad00b2CAS |
McCue, M. D., and Lillywhite, H. B. (2002). Oxygen consumption and the energetics of island-dwelling Florida cottonmouth snakes. Physiological and Biochemical Zoology 75, 165–178.
| Oxygen consumption and the energetics of island-dwelling Florida cottonmouth snakes.Crossref | GoogleScholarGoogle Scholar |
McCue, M. D., Bennett, A. F., and Hicks, J. W. (2005). The effect of meal composition on specific dynamic action in Burmese pythons (Python molurus). Physiological and Biochemical Zoology 78, 182–192.
| The effect of meal composition on specific dynamic action in Burmese pythons (Python molurus).Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2M7ks1OqtQ%3D%3D&md5=b5be8e120c7e1b11431521dabae59356CAS |
Nagy, K. A. (2000). Energy costs of growth in neonate reptiles. Herpetological Monographs 14, 378–387.
| Energy costs of growth in neonate reptiles.Crossref | GoogleScholarGoogle Scholar |
Ott, B. D., and Secor, S. M. (2007). Adaptive regulation of digestive performance in the genus Python. The Journal of Experimental Biology 210, 340–356.
| Adaptive regulation of digestive performance in the genus Python.Crossref | GoogleScholarGoogle Scholar |
Packard, G. C., and Boardman, T. J. (1999). The use of percentages and size-specific indices to normalize physiological data for variation in body size: wasted time, wasted effort? Comparative Biochemistry and Physiology 122A, 37–44.
| 1:CAS:528:DyaK1MXhsF2gtbg%3D&md5=612f6c5271b934ab5199fa33194bfe95CAS |
Peucker, S. K. J., and Jack, R. H. (2006). Crocodile farming research: on-farm research of pelleted feed for crocodiles. Australian Government Rural Industries Research and Development Corporation. RIRDC Publication No. 06/016.
Pope, C. H. (1961). ‘The Giant Snakes.’ (Knopf: New York.)
Sah, S. A. M., and Stuebing, R. B. (1996). Diet, growth and movements of juvenile crocodiles Crocodylus porosus Schneider in the Klias River, Sabah, Malaysia. Journal of Tropical Ecology 12, 651–662.
| Diet, growth and movements of juvenile crocodiles Crocodylus porosus Schneider in the Klias River, Sabah, Malaysia.Crossref | GoogleScholarGoogle Scholar |
Secor, S. M. (2008). Digestive physiology of the Burmese python: broad regulation of integrated performance. The Journal of Experimental Biology 211, 3767–3774.
| Digestive physiology of the Burmese python: broad regulation of integrated performance.Crossref | GoogleScholarGoogle Scholar |
Secor, S. M. (2009). Specific dynamic action: a review of the postprandial metabolic response. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology 179, 1–56.
| Specific dynamic action: a review of the postprandial metabolic response.Crossref | GoogleScholarGoogle Scholar |
Secor, S. M., and Diamond, J. (1997). Determinants of the postfeeding metabolic response of Burmese pythons, Python molurus. Physiological Zoology 70, 202–212.
| 1:STN:280:DyaK2sznsFSiug%3D%3D&md5=53d7801b505b3ed27a3ae7a8d7e57505CAS |
Secor, S. M., and Diamond, J. M. (2000). Evolution of regulatory responses to feeding in snakes. Physiological and Biochemical Zoology 73, 123–141.
| Evolution of regulatory responses to feeding in snakes.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3c3msVahtQ%3D%3D&md5=fb874b236a945cd64344e49933a03c0aCAS |
Secor, S. M., and Nagy, K. A. (1994). Bioenergetic correlates of foraging mode for the snakes Crotalus cerastes and Masticophis flagellum. Ecology 75, 1600–1614.
| Bioenergetic correlates of foraging mode for the snakes Crotalus cerastes and Masticophis flagellum.Crossref | GoogleScholarGoogle Scholar |
Secor, S. M., and Phillips, J. A. (1997). Specific dynamic action of a large carnivorous lizard, Varanus albigularis. Comparative Biochemistry and Physiology 117A, 515–522.
| 1:CAS:528:DyaK2sXktFaktbc%3D&md5=92067c1c024df94d5f20bb6051e14702CAS |
Shine, R., Harlow, P. S., Keogh, J. S., and Boeadi, (1998). The influence of sex and body size on food habits of a giant tropical snake, Python reticulatus. Functional Ecology 12, 248–258.
| The influence of sex and body size on food habits of a giant tropical snake, Python reticulatus.Crossref | GoogleScholarGoogle Scholar |
Starck, J. M., Cruz-Neto, A. P., and Abe, A. S. (2007). Physiological and morphological responses to feeding in broad-nosed caiman (Caiman latirostris). The Journal of Experimental Biology 210, 2033–2045.
| Physiological and morphological responses to feeding in broad-nosed caiman (Caiman latirostris).Crossref | GoogleScholarGoogle Scholar |
Staton, M. A., Edwards, H. M., Brisbin, I. L., Joanen, T., and McNease, L. (1992). The influence of environmental temperature and dietary factors on utilization of dietary energy and protein in purified diets by alligators, Alligator mississippiensis (Daudin). Aquaculture 107, 369–381.
| The influence of environmental temperature and dietary factors on utilization of dietary energy and protein in purified diets by alligators, Alligator mississippiensis (Daudin).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXhtVWjsrs%3D&md5=aa74472ec1f539ecc7d6f087e7dd275eCAS |
Taylor, J. A. (1979). The foods and feeding habits of subadult Crocodylus porosus Schneider in northern Australia. Australian Wildlife Research 6, 347–359.
| The foods and feeding habits of subadult Crocodylus porosus Schneider in northern Australia.Crossref | GoogleScholarGoogle Scholar |
Thompson, G. G., and Withers, P. C. (1998). Metabolic rate of neonate goannas (Squamata: Varanidae). Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology 120, 625–631.
| Metabolic rate of neonate goannas (Squamata: Varanidae).Crossref | GoogleScholarGoogle Scholar |
Thompson, G. G., and Withers, P. C. (1999). Effect of sloughing and digestion on metabolic rate in the Australian carpet python, Morelia spilota imbricata. Australian Journal of Zoology 47, 605–610.
| Effect of sloughing and digestion on metabolic rate in the Australian carpet python, Morelia spilota imbricata.Crossref | GoogleScholarGoogle Scholar |
Tucker, A. D., Limpus, C. J., McCallum, H. I., and McDonald, K. R. (1996). Ontogenetic dietary partitioning by Crocodylus johnstoni during the dry season. Copeia 1996, 978–988.
| Ontogenetic dietary partitioning by Crocodylus johnstoni during the dry season.Crossref | GoogleScholarGoogle Scholar |
Van Barneveld, R. J., Peucker, S., Davis, B., and Mayer, R. (2004). Development of manufactured feeds for Crocodylus porosus. In ‘Proceedings of the 17th Working Meeting of the IUCN-SSC Crocodile Specialist Group. IUCN, Gland’. pp. 102–110.
Webb, G. J. W., and Manolis, S. C. (1989). ‘Crocodiles of Australia: A Natural History.’ (Reed New Holland.)
Webb, G. J. W., Manolis, S. C., and Buckworth, R. (1982). Crocodylus johnstoni in the McKinlay River Area, N.T. I. Variation in the diet, and a new method of assessing the relative importance of prey. Australian Journal of Zoology 30, 877–899.
| Crocodylus johnstoni in the McKinlay River Area, N.T. I. Variation in the diet, and a new method of assessing the relative importance of prey.Crossref | GoogleScholarGoogle Scholar |
Webb, G. J. W., Manolis, S. C., and Whitehead, P. J. (1987). ‘Wildlife Management: Crocodiles and Alligators.’ (Surrey Beatty: Sydney.)
Webb, G. J. W., Hollis, G. J., and Manolis, S. C. (1991). Feeding, growth, and food conversion rates of wild juvenile saltwater crocodiles (Crocodylus porosus). Journal of Herpetology 25, 462–473.
| Feeding, growth, and food conversion rates of wild juvenile saltwater crocodiles (Crocodylus porosus).Crossref | GoogleScholarGoogle Scholar |
Withers, P. C. (1977). Measurement of VO2 , Vco 2, and evaporative water loss with a flow-through mask. Journal of Applied Physiology 42, 120–123.
| 1:STN:280:DyaE2s%2FptlKgug%3D%3D&md5=d793bf3bea08b4286596ecf44a947e85CAS |
Withers, P. C. (2001). Design, calibration and calculation for flow-through respirometry systems. Australian Journal of Zoology 49, 445–461.
| Design, calibration and calculation for flow-through respirometry systems.Crossref | GoogleScholarGoogle Scholar |
Zaidan, F., and Beaupre, S. J. (2003). Effects of body mass, meal size, fast length, and temperature on specific dynamic action in the timber rattlesnake (Crotalus horridus). Physiological and Biochemical Zoology 76, 447–458.
| Effects of body mass, meal size, fast length, and temperature on specific dynamic action in the timber rattlesnake (Crotalus horridus).Crossref | GoogleScholarGoogle Scholar |
