Nutritional responses to different diet quality in the subterranean rodent Ctenomys talarum (tuco-tucos) (original) (raw)
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Journal of Experimental Zoology Part A: Ecological Genetics and Physiology, 2011
We studied the occurrence of digestive strategies at different levels in females of the subterranean herbivorous rodent Ctenomys talarum living in their natural habitat. We determined the dimensions of different parts of the gastrointestinal tract and organs along as the activity of key digestive enzymes(sucrase, maltase and N-aminopeptidase) in small intestine in females seasonally caught. Females of C. talarum did not show seasonal variations in the mass of the different parts of the gastrointestinal tract. In nonreproductive females large intestine was longer in autumn, whereas reproductive females did not show seasonal variations in the length of the different parts of the gut. Females of C. talarum exhibited a high sucrose, maltase and N-aminopeptidase activity in small intestine, although these activities were higher in small intestine of females caught in autumn (nonreproductive) than in females caught in winter (reproductive). The results show that C. talarum females exhibit characteristics in the gut at the morphological and biochemical level, which could represent digestive strategies to face the constraints imposed by their costly particular way of life.
Digestive strategies in the South American subterranean rodent Ctenomys talarum
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2008
Ctenomys talarum is a subterranean herbivorous rodent which due to its particular life style is frequently exposed to variations in surface environmental conditions (i.e. food quality and availability, temperature). Thus, unlike other subterranean rodents, C. talarum has to buffer both the surface and burrow challenging environmental conditions. We studied the occurrence of digestive strategies at different levels of C. talarum living in their natural habitat. We determined the dimensions of different parts of the gastrointestinal tract and organs along as the activity of key digestive enzymes (disaccharidase, N-aminopeptidase) in different parts of the gut in individuals seasonally caught. The results show that C. talarum exhibits characteristics in the gut at the biochemical level (high disaccharidase activities in small intestine, high N-aminopeptidase activity in the caecum and large intestine, and a seasonal differential modulation of N-aminopeptidase activity in small and large intestines), which could represent adaptive strategies to face seasonal variations in key environmental factors.
Studies on Neotropical Fauna and Environment, 2003
The seasonal diet of Ctenomys mendocinus was determined in a habitat of the Andean Precordillera, through microhistological analyses of stomach contents and in relation to food availability. Diet included 23 genera of plants and only 6 of them were consumed with frequencies higher than 4%. The grasses Stipa and Elymus comprised about 80% of the diet. A high proportion of aerial plant material was registered throughout the year suggesting a tendency to forage on the surface. Dietary selectivity was evidenced by a preferential consumption of grasses and avoidance of shrubs. Moreover, most dietary items frequently used were eaten in proportions that differed from their availabilities. This non-opportunistic feeding behavior, specialized in a few dietary items, did not agree with the one expected for a subterranean rodent inhabiting an environment with severe climatic conditions, low food availability and patchy distribution of food resources.
Dietary preferences of two sympatric subterranean rodent populations in Argentina
Revista Chilena de …, 1995
We determined the dietary habits of two sympatric and allotopic populations of Ctenomys (C. australis and C. talarum) that inhabit a natural dune grassland on the sea coast at Necochea, Buenos Aires Province, Argentina. Both species were found to be generalist herbivores as they consumed almost all plant species available in the grassland. Contrary to what we had expected, they fed principally on the aerial fraction of the vegetation, and preferred grasses overforbs. The greater proportion of the subterranean fraction in autumn and winter in C. australis diets compared to C. tala rum might be related to differences in the vegetation around the burrows they inhabit. Ctenomys australis and C. talarum diets differed markedly only in September; however, these differences may not have been totally seasonal, there may also have been a spatial effect due to the soil structure of the sympatric area. Ctenomys australis and C. tala rum distributions seem to be related to soil characteristics with individual animals feeding and selecting mainly among the vegetal species in their own home range. The results of this study show that these species of Ctenomys present a feeding strategy which is adaptative in subterranean rodents due to their high digging cost and to the low available energy to explore in their subterranean environment.
Mammalia, 2018
We examined the feeding strategy of two dominant rodents, the common vole (Microtus arvalis) and the pygmy field mouse (Apodemus uralensis), in set-aside fields over a period of 1 year. Diet analysis revealed dominance of green plant shoots in common vole’s diet and seeds in the diet of the pygmy field mouse. Food availability in the set-aside fields was strongly correlated with the diet of the herbivorous common vole, but not with that of the granivorous pygmy-field mouse. Both feeding strategies reflect specific morphological adaptations of the digestive tract of both species. A comparison of the gastrointestinal tract (GIT; length and mass without oesophagus; including contents) of the common vole and pygmy field mouse revealed a correlation between body size and length and the GIT weight in both species. The common vole had a proportionally heavier GIT with a larger of the common vole and pygmy field mouse relative proportion of caecum. The GIT length was proportionally greater ...
We characterize the flexibility in digestive performance in degus (Octodon degus) an herbivorous rodent. We tested the hypothesis that dietary and physiological-digestive flexibility are correlated. Degus were fed with artificial diets of different chemical composition from weaning to adulthood and their digestive performance was measured through records of apparent digestibility. The starch content of the acclimation diet was not correlated with protein digestibility nor was it correlated with starch digestibility. In addition, digestive tract morphology was not affected by dietary treatments. Hence, an absence of morphological and physiological flexibility related to digestive traits was observed in degus. The lower flexibility in digestive performance given by our dietary experimental treatments of degus, may be an evolutionary constraint related to their specialized herbivorous food habits. Comparative Biochemistry and Physiology, Part A 151 (2008) 455 -460 www.elsevier.com/locate/cbpa ☆ This paper is part of the 5th special issue of CBP dedicated to The Face of Latin American Comparative Biochemistry and Physiology organized by Marcelo Hermes-Lima (Brazil) and co-edited by Carlos Navas (Brazil), Rene Beleboni (Brazil), Carolina A. Freire (Brazil), Tania Zenteno-Savín (Mexico) and the editors of CBP. This issue is dedicated to the memory of Knut Schmidt-Nielsen (1915-2007), a great mind in comparative physiology, with books translated into 16 languages, including Spanish and Portuguese, and Cicero Lima , journalist, science lover and Hermes-Lima's dad.
Comparative Biochemistry and Physiology Part A: Physiology, 1997
Differences in feeding rates and digestive efficiency of alternative experimental diets differing in cellulose or fiber and a secondary metabolite (the hydrolyzable tannin, tannic acid [TA]) were assessed with the herbivorous burrowing caviomorph rodent Occodon degas (degu). Degus live in open scrub subjected to summer droughts. The in vitro activity of the digestive enzyme sucrase was not signihcantly different between treatments with high and low TA. Analysis of the whole organism allowed us to conclude that in vitro analyses of enzymatic digestive activity and plant defenses cannot be used to explain and fully understand the physiological and behavioral effects of plant defenses on mammalian herbivores. We observed no body mass reduction due to effects of dietary treatments. 0. degas seemed to compensate for nutritionally poor food by increasing gut content volume. We conclude that fiber and secondary compounds may influence feeding and digestive strategies and vice versa.
Digestive Parameters and Water Turnover of the Leopard Tortoise.
Leopard tortoises (Stigmochelys pardalis) experience wide fluctuations in environmental conditions and unpredictable availability of food and water within the Nama-Karoo biome. It was hypothesised that tortoises fed two diets differing in preformed water and fibre content would have differing food intake, gut transit rate, assimilation efficiency, faecal and urinary water loss, and urine concentrations. It was predicted that tortoises fed these contrasting diets would attempt to maintain energy and water balance by altering their digestive parameters. Leopard tortoises fed lucerne (Medicago sativa) had a low food intake coupled with long gut transit times, which resulted in the lowest amount of faecal energy and faecal water lost. Tortoises fed tomatoes (Solanum lycopersicum) had higher food intake and faster gut transit times, but more energy and water was lost in the faeces. However, daily energy assimilated and assimilation efficiency were comparable between tortoises fed the two diets. Urine osmolality was significantly different between tortoises on the two diets. Results indicate that leopard tortoises can adjust parameters such as transit rate, food intake, water loss and urine osmolality to maintain body mass, water and energy balance in response to a high fibre, low water content and a low fibre, high water content diet. This study suggests that this digestive flexibility allows leopard tortoises in the wild to take advantage of unpredictable food and water resources.