Digestive enzyme activities in the guts of bonnethead sharks (Sphyrna tiburo) provide insight into their digestive strategy and evidence for microbial digestion in their hindguts
| Autor: | Yannis P. Papastamatiou, Donovan P. German, Parth Jhaveri |
|---|---|
| Přispěvatelé: | University of St Andrews. School of Biology |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Time Factors
Physiology Colon QH301 Biology Bonnethead NDAS Context (language use) Chitin Biochemistry Aminopeptidases Maltase QH301 Acetylglucosaminidase medicine Animals Trypsin Lipase Intestinal Mucosa Molecular Biology Pancreas QL Elasmobranch biology Sphyrna Microbiota beta-Glucosidase QL Zoology biology.organism_classification β-Glucosidase Intestines Spiral intestine medicine.anatomical_structure Digestive enzyme biology.protein Sharks Carbohydrate Metabolism Digestion Digestive System medicine.drug Peptide Hydrolases |
| Popis: | Few investigations have studied digestive enzyme activities in the alimentary tracts of sharks to gain insight into how these organisms digest their meals. In this study, we examined the activity levels of proteases, carbohydrases, and lipase in the pancreas, and along the anterior intestine, spiral intestine, and colon of the bonnethead shark, Sphyrna tiburo. We then interpreted our data in the context of a rate-yield continuum to discern this shark's digestive strategy. Our data show anticipated decreasing patterns in the activities of pancreatic enzymes moving posteriorly along the gut, but also show mid spiral intestine peaks in aminopeptidase and lipase activities, which support the spiral intestine as the main site of absorption in bonnetheads. Interestingly, we observed spikes in the activity levels of N-acetyl-β-d-glucosaminidase and β-glucosidase in the bonnethead colon, and these chitin- and cellulose-degrading enzymes, respectively, are likely of microbial origin in this distal gut region. Taken in the context of intake and relatively long transit times of food through the gut, the colonic spikes in N-acetyl-β-d-glucosaminidase and β-glucosidase activities suggest that bonnetheads take a yield-maximizing strategy to the digestive process, with some reliance on microbial digestion in their hindguts. This is one of the first studies to examine digestive enzyme activities along the gut of any shark, and importantly, the data match with previous observations that sharks take an extended time to digest their meals (consistent with a yield-maximizing digestive strategy) and that the spiral intestine is the primary site of absorption in sharks. Postprint |
| Databáze: | OpenAIRE |
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