PRELIMINARY OBSERVATIONS ON THE DIGESTIVE ENZYME SYSTEM OF THE BEAVER (CASTOR CANADENSIS)

1957 ◽  
Vol 35 (3) ◽  
pp. 449-452 ◽  
Author(s):  
W. D. Kitts ◽  
R. J. Bose ◽  
A. J. Wood ◽  
I. McT. Cowan
Keyword(s):  
Body Mass ◽  
Enzyme System ◽  
Digestive Enzyme ◽  
Castor Canadensis ◽  
Cellular System ◽  
Amylolytic Activity ◽  
Cellulolytic Activity ◽  
Gastric Digestion

Results presented suggest that gastric digestion in the beaver is similar to that in other mammals. The more or less elaborate cardiogastric cellular system of the beaver seems to be concerned with the elaboration of pepsin and does not produce a mammalian cellulase. Some evidence of cellulolytic activity has been found in the caecal contents and is attributed to a commensal microflora. Pancreatic amylolytic activity of the beaver per unit body mass appears to be somewhat lower than in the pig.

Size, shape, and surface area of beaver, Castor canadensis, a semiaquatic mammal

1993 ◽  
Vol 71 (5) ◽  
pp. 876-882 ◽  
Author(s):  
P. S. Reynolds
Keyword(s):  
Surface Area ◽  
Body Mass ◽  
Marine Mammal ◽  
Body Shape ◽  
Castor Canadensis ◽  
Total Surface Area ◽  
Energetic Efficiency ◽  
Terrestrial Mammals ◽  
Surface Areas ◽  
Average Surface Area

The beaver, Castor canadensis, is a large, herbivorous, semiaquatic rodent. Beaver forage on land as well as in water; thus functional compromise between competing activities should result in a less streamlined body shape than expected for a similarly sized marine mammal. Standard morphometrics and surface areas of 70 Wisconsin beaver ranging in size from 5 to 35 kg were measured. Geometric similarity of surface area was maintained during growth (i.e., area was proportional to body mass raised to the 2/3 power). Scaly-tail area was positively allometric with body mass; hind foot web area was weakly negatively allometric. The surface area of the unfurred extremities (hind feet and scaly tail) comprised 30% of the total surface area of adults and over 50% for younger beaver. The average surface area of 21 adult beaver (mean body mass = 20 kg) was 0.52 m2. This value was significantly lower (P < 0.001) than predicted from the Meeh equation for terrestrial mammals, but similar to that expected for a marine mammal of equivalent mass. Body shape was described by the fineness ratio (a hydrodynamic index of streamlining). The fineness ratio for beaver was 4.8, a value similar to that for phocid seals. Therefore, in spite of expected constraints on body shape imposed by herbivory and the competing demands of terrestrial and aquatic foraging, beaver do not differ significantly in overall shape from other, more aquatic, species. However, shape alone is not a reliable indicator of either hydrodynamic or energetic efficiency. Future comparative studies should incorporate both phylogeny and biomechanical data into evaluations of mammalian morphology.

scholarly journals Digestive enzyme system of larvae of different freshwater teleosts and its differentiation during the initial phase of exogenous feeding

2017 ◽  
Vol 62 (No. 10) ◽  
pp. 403-416 ◽  
Author(s):  
F. Lahnsteiner
Keyword(s):  
Digestive System ◽  
Enzyme System ◽  
Digestive Enzyme ◽  
Sander Lucioperca ◽  
Thymallus Thymallus ◽  
Exogenous Feeding ◽  
First Feeding ◽  
Histological Characteristics ◽  
Species Specific ◽  
Freshwater Teleosts

Activities of digestive enzymes and main histological characteristics of the intestine were investigated in larvae of three salmonid species (Coregonus maraena, C. atterensis, Thymallus thymallus), of burbot (Lota lota), and pikeperch (Sander lucioperca) at the onset of exogenous feeding (0 day degrees (°d)) and at 250°d thereafter. At the onset of exogenous feeding the activities of proteolytic, lipolytic, and carbohydrate splitting enzymes were detected in the intestines of all species. The enzymatic activities showed significant species specific differences indicating specializations in functionality and digestion ability. In C. atterensis and L. lota the activities of most enzymes were low in comparison to the other investigated species and therefore their digestive system was only poorly developed. In S. lucioperca it was moderately developed and in T. thymallus and C. maraena well-developed. After 250°d, the activities of the investigated enzymes changed in a very species specific way. Histologically, the intestines of the investigated species revealed no species specific differentiations at the onset of the first feeding with the exception of the absence of goblet cells in L. lota and C. atterensis. These differentiated after 250°d.

Characterization of an immobilized digestive enzyme system for determination of protein digestibility

1984 ◽  
Vol 32 (2) ◽  
pp. 334-339 ◽  
Author(s):  
David H. Porter ◽  
Harold E. Swaisgood ◽  
George L. Catignani
Keyword(s):  
Enzyme System ◽  
Digestive Enzyme ◽  
Protein Digestibility

scholarly journals Duplications and Functional Convergence of Intestinal Carbohydrate-Digesting Enzymes

2020 ◽  
Vol 37 (6) ◽  
pp. 1657-1666 ◽  
Author(s):  
Antonio Brun ◽  
Daniel Mendez-Aranda ◽  
Melisa E Magallanes ◽  
William H Karasov ◽  
Carlos Martínez del Rio ◽  
...  
Keyword(s):  
Dietary Diversity ◽  
Enzyme System ◽  
Digestive Enzyme ◽  
Starch Digestion ◽  
Intestinal Enzymes ◽  
Enzyme Variation ◽  
Functional Convergence ◽  
Behavioral Features

Abstract Vertebrate diets and digestive physiologies vary tremendously. Although the contribution of ecological and behavioral features to such diversity is well documented, the roles and identities of individual intestinal enzymes shaping digestive traits remain largely unexplored. Here, we show that the sucrase-isomaltase (SI)/maltase-glucoamylase (MGAM) dual enzyme system long assumed to be the conserved disaccharide and starch digestion framework in all vertebrates is absent in many lineages. Our analyses indicate that independent duplications of an ancestral SI gave rise to the mammalian-specific MGAM, as well as to other duplicates in fish and birds. Strikingly, the duplicated avian enzyme exhibits similar activities to MGAM, revealing an unexpected case of functional convergence. Our results highlight digestive enzyme variation as a key uncharacterized component of dietary diversity in vertebrates.

scholarly journals Pelvic sexual dimorphism among species monomorphic in body size: relationship to relative newborn body mass

2015 ◽  
Vol 97 (2) ◽  
pp. 503-517 ◽  
Author(s):  
Robert G. Tague
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Body Mass ◽  
Castor Canadensis ◽  
Published Data ◽  
Sciurus Carolinensis ◽  
Sylvilagus Floridanus ◽  
Lower Prevalence ◽  
Joint Fusion ◽  
Pelvic Sexual Dimorphism

Abstract Females have larger pelves than males among eutherians to mitigate obstetrical difficulty. This study addresses 3 issues concerning pelvic sexual dimorphism using 8 species that are sexually monomorphic in nonpelvic size: Aotus azarae , Castor canadensis , Dasypus novemcinctus , Hylobates lar , Saguinus geoffroyi , Sciurus carolinensis , Sylvilagus floridanus , and Urocyon cinereoargenteus . Using published data to compute the index of relative newborn body mass (RNBM = [newborn body mass/adult female body mass]100%) for 266 eutherian species, A. azarae , H. lar , and S. geoffroyi are characterized as giving birth to relatively large newborns and the other 5 species as giving birth to relatively small newborns. The 3 issues are, compared to species giving birth to relatively small newborns, whether species that give birth to relatively large newborns have 1) higher magnitude of pelvic sexual size dimorphism (SSD), 2) lower prevalence of pelvic joint fusion, and 3) dissociation between pelvic and nonpelvic sizes. Nine measures of the pelvis were taken, and fusion of interpubic and sacroiliac joints was observed. Species grouped by high and low RNBM do not differ significantly in magnitude of SSD of pelvic inlet circumference. Species with high RNBM have significantly lower prevalence of interpubic joint fusion than those with low RNBM. Sexes do not differ in their multiple correlation coefficients between inlet circumference and nonpelvic body size in 7 of 8 species. Results suggest that 1) there are multiple anatomical pathways for pelvic obstetrical sufficiency, 2) an unfused interpubic joint is obstetrically advantageous, and 3) relative newborn size does not change the association between pelvic and nonpelvic size in females and males.

Electron Microscopic and Isozyme Study of a Case of Ochronosis

1972 ◽  
Vol 30 ◽  
pp. 88-89
Author(s):  
Jay W. Cha ◽  
Perry J. Melnick
Keyword(s):  
Benzene Ring ◽  
Enzyme System ◽  
Homogentisic Acid ◽  
Degenerative Changes ◽  
Acid Oxidase ◽  
Electron Microscopic ◽  
Tyrosine Metabolism ◽  
Collagenous Tissues

Hereditary ochronosis in very few cases has been examined electron microscopically or histochemically. In this disease homogentisic acid, a normal intermediary of tyrosine metabolism, forms in excessive amounts. This is believed to be due to absence or defective activity of homogentisic acid oxidase, an enzyme system necessary to break the benzene ring and to further break it down to fumaric and acetoacetic acids. Ochronotic pigment, a polymerized form of homogentisic acid, deposits mainly in mesenchymal tissues. There has been a question whether the pigment originates from the collagenous tissues, or deposits passively, where in contrast to melanin it induces degenerative changes.

191: Does the Body Mass Index Affect the Outcome Following Reconstruction of Orthotopic Neobladder?

2007 ◽  
Vol 177 (4S) ◽  
pp. 64-64
Author(s):  
Murugesan Manoharan ◽  
Martha A. Reyes ◽  
Alan M. Nieder ◽  
Bruce R. Kava ◽  
MarkS Soloway
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
The Body ◽  
Orthotopic Neobladder
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