Restricted Food Supply Research Articles

Altered temperature and restricted food supply reduce pH tolerance in both young and adult ascidians

ABSTRACT Ocean acidification poses a threat to marine ecosystems. Understanding of how responses to acidification differ among life stages and how they are moderated by co-occurring stressors remains limited. This study investigated the tolerance of ascidians to acidification, under regional cooling, as experienced along the west coast of South Africa and in other eastern boundary upwelling systems. Critical pH minima (CpHmin) were established for young and adult Ciona robusta and young and adult colonies of Diplosoma listerianum, Botryllus schlosseri, Botryllus gregalis, under restricted and unrestricted food supply, at two temperatures (13°C (current) and 9°C (future cooling)). pH was reduced at a rate of 0.1 units per day, starting from the current condition of 7.9 pH. For all species, responses to decreasing pH were affected by life stage, temperature and food supply. Young individuals and young colonies were least tolerant to acidification. Regardless of life stage, cooling reduced pH tolerance, as did restricted food supply. These results suggest that tolerance to acidification is lowest during early life stages and will be exacerbated by climate change induced cooling. However, high productivity in upwelling regions may result in high food supply that could ultimately buffer against the negative effects of cooling on pH tolerance.

The non-linear impacts of crude oil prices and trade openness on the foreign income of Bangladesh

A Market based study was conducted in the high (Tanore Upazila) and low (Natore Upazila) drought prone areas over the period of twelve months with the aims to know the impacts of drought on the market. Drought inhibits production, the inflow of agricultural produces and food supply in high drought market areas. Availability, diversity, price and sources of plant species become more restricted by the severe drought. The high drought market area shows less availability of the produces with low diversity and high prices. These attributes arrest consumer’s behavior in food consumption patterns and restricted food supply in high drought market. Low drought market area shows normal production, regular inflows of agricultural produces. Mostly drought affects market in the Kharif-2 season. More local varieties were found in the low drought market during Rabi season. Appropriate drought forecasting in advance and drought insurance can protect production loss and ensure market supply. IUBAT Review—A Multidisciplinary Academic Journal, 6 (1): 61-76

Impacts of Drought on the Market in the Northwest Region of Bangladesh: Availability, Diversity and Price

A Market based study was conducted in the high (Tanore Upazila) and low (Natore Upazila) drought prone areas over the period of twelve months with the aims to know the impacts of drought on the market. Drought inhibits production, the inflow of agricultural produces and food supply in high drought market areas. Availability, diversity, price and sources of plant species become more restricted by the severe drought. The high drought market area shows less availability of the produces with low diversity and high prices. These attributes arrest consumer’s behavior in food consumption patterns and restricted food supply in high drought market. Low drought market area shows normal production, regular inflows of agricultural produces. Mostly drought affects market in the Kharif-2 season. More local varieties were found in the low drought market during Rabi season. Appropriate drought forecasting in advance and drought insurance can protect production loss and ensure market supply. IUBAT Review—A Multidisciplinary Academic Journal, 6 (1): 47-60

Assessing Potential Investment Return of Basil (Ocimum Basillicum P.) using Fuzzy Logic and Investment Analysis Criteria for Environmental-Based Agriculture

Indonesia is one of Southeast Asia's most populous and big countries. It was well-known for its richness of natural resources. Indonesia is one of the world's largest tropical countries, because of its tropical environment. According to the statistics, however, arable land in Indonesia has declined dramatically over the years in response to increased demand for residential areas. This data reveals a fairly alarming fact: It is feasible that, despite its wealth of natural resources, Indonesia could one day be unable to meet its domestic food demands. Furthermore, rivalry and obstacles faced by Indonesian farmers may exacerbate the country's restricted food supply. The assessments of potential investment in basil plant (Ocimum basillicum P.) were conducted, to support the agricultural innovation to be more appealing among stakeholders, researchers, and farmers. In assessing the potential investment, the financial aspect of the feasibility study is used in this study, where this assessment was commonly used in planning and forecasting the financial gains of a project or investment. The Decision Support Model (DSM) was using a fuzzy logic method in determining the investment decision. We hope this study will provide better analysis and accurate decisions for stakeholders, researchers, and farmers.

Larval nutrition influences adult fat stores and starvation resistance in Drosophila.

Insulin plays a major role in connecting nutrient availability to energy homeostasis by regulating metabolic pathways. Defects in insulin signalling is the primary cause for diabetes, obesity and various metabolic disorders. Nutritional status during growth and developmental stages play a crucial role in determining adult size, fecundity and ageing. However, the association between developmental nutrition and adult metabolic disorders has not been fully explored. Here, we address the effects of nutrient status during the larval growth phase on adult metabolism in Drosophila. We report that restricted food supply in larvae led to higher fat reserves and starvation resistance in mature adult flies, which we attribute to low insulin signalling. A lesser amount of stored fat was mobilised during early adult stages and during acute starvation, which accounts for the metabolic effects. Furthermore, larval diet influenced the expression of fat mobilisation genes brummer and lipid storage droplet-2 in adult flies, which led to the metabolic phenotypes reported here. Thus, the restricted nutrient environment in developing larvae led to adaptive changes that entrain the adult flies for scarce food availability.

Which was the habitat of early Eocene planktic foraminifer Chiloguembelina? Stable isotope paleobiology from the Atlantic Ocean and implication for paleoceanographic reconstructions

The planktic foraminiferal genus Chiloguembelina is characterized by tiny test and biserial disposition of chambers. Largely accepted ecological interpretation ascribes biserial planktic foraminifera as eutrophic and low-oxygen tolerant forms inhabiting the Oxygen Minimum Zone (OMZ). However, this ecological interpretation does not agree with all available data from Cenozoic record. Actually, chiloguembelinid stable isotope paleobiology is highly variable through time and space as it indicates mixed-layer habitat on earliest Eocene, middle Eocene and Late Oligocene but thermocline habitat during middle Eocene from northwest Atlantic Ocean. However, chiloguembelinid stable-isotope data were so far lacking from the early Eocene. This interval includes the early Eocene Climatic Optimum (EECO, ~53–48 Ma) that is the crucial time when Earth's surface temperatures and pCO2 reached their maximum levels in the Cenozoic. We present here new chiloguembelinid oxygen and carbon stable-isotope data from early Eocene Atlantic Ocean Drilling Program (ODP) Sites 1051, 1258, 1263 and 690. We also generate new data on Chiloguembelina abundance from Site 1051 and compare our record with those previously published from sites 1263 and 1258 in order to correlate the early Eocene paleoceanographic distribution of this genus through the Atlantic Ocean. Interestingly, Chiloguembelina became virtually absent at the beginning of the EECO in the subtropical, equatorial and temperate Atlantic sites. Our findings clearly prove that early Eocene Chiloguembelina occupied a deep-water niche throughout the Atlantic Ocean as demonstrated by its stable isotope signature close to the deep-dweller Subbotina and benthic foraminifera. These evidences provide critical paleoceanographic implications suggesting that intermediate water temperatures probably rose significantly during the EECO thus becoming too warm for this genus. Elevated ocean temperatures enhanced the rate of bacterial respiration and remineralization significantly thus resulting in more efficient recycling of nutrients higher in the water column. This would have induced a restricted food supply deeper in the thermocline and cut out the chiloguembelinid niche. The agreement of the observed decline in abundance of chiloguembelinids at the study sites with recently published foraminifera-bound nitrogen isotope data suggests that enhanced oxygenation of the thermocline in the early EECO might have also played a major role in driving the disappearance of chiloguembelinids, which in itself represent a new evidence for the largely accepted view that these forms inhabited the OMZ. Very likely a combination of reduced food supply, increase in thermocline temperature and oxygen content resulted in the decline of chiloguembelinids in the early EECO.

Foraging behaviour and diet in two sympatric shrike species during autumn migration across the Arabian Peninsula.

In situations of restricted food supply, the trophic niches of closely-related species of animals should be separate. For sit-and-wait hunters, such as shrikes, this is associated with competition for food and hunting sites. In the present study, the foraging behaviour of two shrike species – Red-tailed Shrike Lanius phoenicuroides and Red-backed Shrike Lanius collurio – was studied in a desert habitat in Oman. The fieldwork was carried out in September 2019, during the peak migration of these birds. Their behaviour was recorded in detail during 30-minute observation bouts. A General Linear Mixed Model with logit link function and binomial error variance was used to compare their behaviour. The type of perch and its height did not differ between them, but there were significant differences in their use of look-out posts only in the mean duration of a single perching event, which was more than twice as long in Red-backed Shrike. No differences in prey size were found between the species and hunting success (the ratio of successful attacks to all attacks) was similar in both (RtS-RbS: 46 vs. 61%). Dietary diversity was twice as great in Red-tailed Shrike as in Red-backed Shrike, but in general, their diets did not differ very much. Dietary overlap between the species at this level of prey identification was 92%. This absence of differences in some aspects of behaviour and diet may be due to the similarity of the two species, above all their same body size, and even the possibility of hybridization. If the species compared are so similar due to body size, behaviour and evolutionary relationship their food niches may overlap.

A citizen-based platform reveals the distribution of functional groups inside a large city from the Southern Hemisphere: e-Bird and the urban birds of Santiago (Central Chile)

BackgroundCurrent knowledge of urban bird ecology and biodiversity relies on evidence from cities of the Northern Hemisphere, while the Southern Hemisphere is underrepresented. Santiago is a large city from South America, located in central Chile, which is both a biodiversity hotspot and an Endemic Bird Area. This work is a synthesis, which aims to provide a diversity account for Santiago, and to describe the broad geographic distribution and bird functional patterns.MethodsWe synthesized a seven-year (2009–2016) bird register from the eBird database (21,865 georeferenced registers at Santiago) into a single avifaunal account, along with the observed number of individuals. We complemented these registers by using available literature about Santiago’s avifauna (28 references). We investigated the proportion of native/exotic, migrants/residents, conservation categories, and urban nesting status. We classified Santiago’s birds into seven trophic guilds. We plotted species richness and number of individuals for each functional group, by interpolating trough the Inverse Distance Weighted Method.ResultsWe found that Santiago’s avifauna (46 species) is composed mainly by native (41), resident (38), non-threatened species (46) that breed inside the city (31). Some functional groups inhabit a large portion of Santiago’s urban surface, reaching high values of richness and abundance. Among these groups are the native, urban-nesters and resident species; even though exotics possess low species richness (5), they are abundant and inhabit the complete urban surface of the city.The dominant trophic guilds are omnivorous (11) and granivorous (10). Insectivorous are the third most abundant trophic guild, and show the highest species richness (13).ConclusionThe functional groups with lower species richness are less abundant and display reduced and patchy distributions in Santiago. This is probably because of the low availability of suitable habitats and/or restricted food supply (migrants, carnivorous, nectarivorous, frugivorous, herbivorous and piscivorous). The high insectivorous richness reported in Santiago, along with similar patterns reported in several cities in the Neotropics, provides evidence to postulate a pattern of high species richness of this guild in cities across this biogeographic realm.

Differences in Fat Metabolism Between Predicted Survivors And Non-Survivors of Faecal Peritonitis

A switch from carbohydrate to fat as a fuel source is a hallmark of systemic inflammation. This adaptive reaction allows animals to survive under restricted food supply conditions. However, a prolonged and excessive stimulation of lipid metabolism may be detrimental.

Contrary seasonal changes of rates of nutrient uptake, organ mass, and voluntary food intake in red deer (Cervus elaphus).

Northern ungulates acclimatize to winter conditions with restricted food supply and unfavorable weather conditions by reducing energy expenditure and voluntary food intake. We investigated in a study on red deer whether rates of peptide and glucose transport in the small intestines are also reduced during winter as part of the thrifty phenotype of winter-acclimatized animals, or whether transport rates are increased during winter in order to exploit poor forage more efficiently. Our results support the latter hypothesis. We found in a feeding experiment that total energy intake was considerably lower during winter despite ad libitum feeding. Together with reduced food intake, mass of visceral organs was significantly lower and body fat reserves were used as metabolic fuel in addition to food. However, efficacy of nutrient absorption seemed to be increased simultaneously. Extraction of crude protein from forage was higher in winter animals, at any level of crude protein intake, as indicated by the lower concentration of crude protein in feces. In line with these in vivo results, Ussing chamber experiments revealed greater electrogenic responses to both peptides and glucose in the small intestines of winter-acclimatized animals, and peptide uptake into jejunal brush-border membrane vesicles was increased. We conclude that reduced appetite of red deer during winter avoids energy expenditure for unproductive search of scarcely available food and further renders the energetically costly maintenance of a large gut and visceral organs unnecessary. Nevertheless, extraction of nutrients from forage is more efficient in the winter to attenuate an inevitably negative energy balance.

Grand challenges in nutrition.

No subject pertains more to human life than nutrition. Biologically, this statement is evident. Historically, we are aware of the impact nutrition can have on entire cultures as a result of abundant or diminished and impaired or restricted food supply. Nutrition and food always have been at the heart of human life. Owing to the significance of food and nutrition, the world is facing a continued set of challenges and Frontiers in Nutrition is determined to address all of them. Specifically, in an ever more densely populated world, we will continue to be confronted by problems of hunger on a massive scale, hence Eradicating Extreme Poverty and Hunger is the number one Millenium Development Goal of the UN (1) and the key issue for the post-2015 development agenda (2). At the same time, we observe a growing obesity epidemic in both developed countries and in emerging economies at an alarming velocity. Hunger, malnutrition, and obesity are linked to a variety of health and societal issues, such as impaired development, diabetes, Alzheimer’s disease, and allergies, as well as an environmental burden and impaired economic performance – to name just a few. Yet, at the beginning of the twenty-first century, we are also embracing an era full of opportunity with breathtaking advances in science, agriculture, commerce, and global interaction. So, how do these challenges in the field of nutrition translate into tangible challenges for Frontiers in Nutrition? Ultimately, Frontiers’ ambition has to be directed toward the alleviation of hunger, malnutrition, and obesity. With a sober mindset this can be achieved through the publication of credible, rigorous, and meaningful science within the specialty sections of the journal.

Social Dominance Is Associated with Individual Differences in Heart Rate and Energetic Response to Food Restriction in Female Red Deer

Energy expenditure is a key mechanism underlying animal ecology, yet why individuals often differ in metabolic rate even under identical conditions remains largely unexplained. Individual variation in metabolism might be explained by correlations with other behavioral and physiological traits, with individual syndromes having environment- or state-dependent costs and benefits to fitness. We tested whether social rank within herds of female red deer is associated with individual differences in resting heart rate, an index of metabolic rate, and energetic response to monthly periods of food restriction during winter in a large outdoor enclosure near Vienna, Austria. Social rank had a strong positive effect on average daily heart rate, independent of the effects of food intake, air temperature, body temperature, and body mass. Subordinate individuals had lower heart rates than dominants, and consequently they suffered lower rates of body mass loss during periods of restricted pellet food supply. A greater capacity to minimize energy requirements might benefit the survival of subdominant female red deer during periods of negative energy balance in winter. Our study provides empirical support in a large mammal for linkages in behavior and metabolism within individuals that have environment-dependent consequences to the energy budget.

Intermittent Fasting Modulation of the Diabetic Syndrome in Streptozotocin-Injected Rats

This study investigates the effects of intermittent overnight fasting in streptozotocin-induced diabetic rats (STZ rats). Over 30 days, groups of 5-6 control or STZ rats were allowed free food access, starved overnight, or exposed to a restricted food supply comparable to that ingested by the intermittently fasting animals. Intermittent fasting improved glucose tolerance, increased plasma insulin, and lowered Homeostatis Model Assessment index. Caloric restriction failed to cause such beneficial effects. The β-cell mass, as well as individual β-cell and islet area, was higher in intermittently fasting than in nonfasting STZ rats, whilst the percentage of apoptotic β-cells appeared lower in the former than latter STZ rats. In the calorie-restricted STZ rats, comparable findings were restricted to individual islet area and percentage of apoptotic cells. Hence, it is proposed that intermittent fasting could represent a possible approach to prevent or minimize disturbances of glucose homeostasis in human subjects.

Living unicellular eukaryote Tetrahymena pyriformis as a model for study

Some animals are able to survive for a long time under conditions of drastically reduced oxidative metabolism, called metabolic depression. The most investigated type of metabolic depression is hibernation. Research into the basic properties of liver mitochondria energetics during hibernation is essential for fundamental biology and medicine. However, the absence of a suitable hepatocyte culture makes it impossible to study the characteristic features of mitochondrial metabolic states in living cells during hibernation. We proposed that under selected conditions, the unicellular eukaryote Tetrahymena pyriformis resembles hepatocytes under hibernation, as (i) both cell types survive under condition of restricted food supply, hypoxia, and accumulation of toxic products of metabolism; (ii) the mechanisms for survival during drastically reduced oxidative metabolism probably developed in the ancestors of the eukaryote mitochondria and may be conserved, in somewhat modified forms, in mitochondria of the ciliates and mammalian cells; (iii) mitochondria isolated from rat liver and Tetrahymena pyriformis are similar in their energetics properties. The already published results of experiments with Tetrahymena pyriformis and with mitochondria isolated from the liver of hibernating animals are considered in this paper to support and develop this suggestion. Sharp decreases in the maximal uncoupler-stimulated respiration rates in liver mitochondria isolated from the hibernating animals was described in many publications. The respiration recordings and Mito Tracker Red fluorescence observations in the ciliates were tentatively explained by low ∆Ψ and high ∆pH. Prior to this study the strong decline in ∆Ψ and the subsequent remodeling of mitochondria into the condensed configuration was found during earlier apoptosis induced by suppression of the respiratory activity. On the grounds of these and other data, a hypothesis is put forward that the prerequisite for reducing the oxidative metabolism and mitochondrial transition to hibernation resembles early apoptosis, with initial ∆Ψ decline following mitochondrial matrix transition to a condensed configuration.

Food consumption and growth of Atlantic salmonSalmo salarparr in sub‐Arctic rivers: empirical support for food limitation and competition

The quantitative food consumption and somatic growth of Atlantic salmonSalmo salarparr were compared between three sub‐Arctic rivers in northern Norway and Finland, addressing the potential occurrence of resource limitation and interspecific competition. In one of the rivers, previous resource partitioning studies have suggested severe dietary competition between juvenileS. salarand a dense population of alpine bullheadsCottus poecilopus. It was hypothesized thatS. salarparr in this river would have restricted food consumption and growth rates compared to theS. salarpopulations in the other two rivers where interspecific competition was less likely to occur. The feeding and growth performance differed significantly between theS. salarpopulations. The lowest food acquisition and growth rates were in theS. salarparr population living in sympatry withC. poecilopus, confirming a restricted food supply for theS. salarparr and providing empirical support for the presence of resource limitation and interspecific food competition in this river system. The study reveals thatS. salarparr in sub‐Arctic rivers may experience food limitations resulting in diminished growth rates.

Maternal care in white-tailed deer: trade-off between maintenance and reproduction under food restriction

Lactation is the most energetically costly component of maternal investment in mammals. For large temperate herbivores, summer is characterized by relatively abundant forage but also high energetic needs for lactation and recovery from winter mass loss. We experimentally restricted food supply by about 20%, and compared the nursing and foraging behaviours of control and food-restricted adult female white-tailed deer, Odocoileus virginianus, and their fawns during lactation. We considered two fawn ages: 0–30 days (after which time spent suckling dropped markedly) and 30–80 days (the end of the nursing period). From 0 to 30 days of age, food-restricted fawns performed 17 more suckling bouts/day and spent twice as much time suckling than control fawns. Compared with controls, food-restricted fawns gained 26% less mass from birth to 80 days. Body growth was inversely related to time spent suckling and to the frequency of nursing bouts, but positively related to survival. Food-restricted fawns had twice as many suckling solicitations and rejected suckling attempts as control fawns. Solicitations for allosuckling and successful allosuckling bouts were also more than twice as high in the food-restricted group as in the control group. Mothers and fawns from the food-restricted group spent more time foraging than control individuals. We conclude that a reduction in food availability during summer, which may occur under high intraspecific competition, should lead to drastic changes in foraging and nursing behaviours as well as reduced growth rate of juveniles of large northern herbivores.

Fluctuation of Abundance and Lassa Virus Prevalence in Mastomys natalensis in Guinea, West Africa

Based on empiric surveillance data, the incidence of human Lassa fever (LF) cases in Guinea and other West African countries has been reported to increase during the dry season compared to the rainy season. To investigate possible links with the ecology of the rodent reservoir of the virus, we conducted a 2-year longitudinal survey of Mastomys natalensis in a region of high human Lassa virus (LASV) seropositivity in Guinea. Standardized rodent trapping with similar trapping efforts between seasons was performed in three villages and 53.5% (601/1123) of the animals were identified as M. natalensis using morphometric and molecular criteria. Mean trapping success (TS) of M. natalensis was always higher inside houses than in proximal cultivations. In the dry season, mean TS increased 2-fold inside houses and decreased up to 10-fold outside (p < 0.0001), suggesting aggregation of rodents inside houses due to restricted food supply. 14.5% (80/553) of M. natalensis were tested positive for Lassa virus by reverse transcription-polymerase chain reaction (RT-PCR; range, 5%-30%) and prevalence of the virus was two to three times higher in rodents captured in the rainy season than in the dry season (p < 0.05). Inside houses, however, the LASV prevalence fluctuated nonsignificantly with season. These data suggest that in Guinea the risk of LASV transmission from rodents to humans is present both in the rainy and the dry season, reflected by the occurrence of LF cases throughout the year. In the dry season, however, the increased risk of humans encountering Mastomys and their excreta inside of houses may result in an increase of human Lassa fever cases.

Endocrine disruption, parasites and pollutants in wild freshwater fish.

Disruption of the endocrine system has been shown to occur in wild freshwater fish populations across the globe. Effects range from subtle changes in the physiology and sexual behaviour of fish to permanently altered sexual differentiation, impairment of gonad development and/or altered fertility. A wide variety of adverse environmental conditions may induce endocrine disruption, including sub-optimal temperatures, restricted food supply, low pH, environmental pollutants, and/or parasites. Furthermore, it is conceivable that any/all of these factors could act simultaneously to cause a range of disparate or inter-related effects. Some of the strongest evidence for a link between an adverse health effect, as a consequence of endocrine disruption, and a causative agent(s) is between the condition of intersex in wild roach (Rutlius rutilus) in UK rivers and exposure to effluents from sewage treatment works. The evidence to indicate that intersex in roach (and other cyprinid fish living in these rivers) is caused by chemicals that mimic and/or disrupt hormone function/balance in treated sewage effluent is substantial. There are a few parasites that affect the endocrine system directly in fish, including the tape worm Ligula intestinalis and a few parasites from the micropsora phylum. L. intestinalis acts at the level of the hypothalamus restricting GnRH secretion (resulting in poorly developed gonads) and is one of the very few examples where an endocrine disrupting event has been shown to result in a population-level effect (reducing it). It is well established that many parasites affect the immune system and thus the most common effect of parasites on the endocrine system in fish is likely to be an indirect one.

Nutritional stress changes sex‐specific reproductive allocation in the simultaneously hermaphroditic land snailArianta arbustorum

SummarySex allocation theory predicts that when resources are limited in simultaneous hermaphrodites, the allocation to one sexual function will automatically reduce the resources available to the other function. This study examines the effect of nutritional stress on mating behaviour and male and female reproductive output (dry mass and nitrogen contents of spermatophores, sperm delivered and eggs deposited) in individuals of the simultaneously hermaphroditic land snailArianta arbustorumkept under three different food regimes: ample (100%), restricted (50%) and extremely restricted (25%) food supply.Independent of the extent of nutritional stress, 10–12% of the resources taken up were invested in reproductive output (both gender functions together) and 88–90% in maintenance (including faeces and excretion).Courtship and copulation behaviour was affected by nutritional stress. Snails with an extremely restricted food supply did not mate, except one pair. Individuals with restricted food supply tended to court longer, and copulated for a shorter period, than individuals with ample food supply.Nutritional stress did not affect the number of sperm delivered. However, snails with a restricted food supply produced fewer eggs. Thus, snails kept under nutritional stress invested relatively more resources in the male function than in the female function. Nevertheless, the absolute reproductive output remained highly female biased (&gt;95% in all experimental groups).At the individual level, the existence of a trade‐off between resources invested in the malevsthe female function could not be confirmed. However, there was a trade‐off between nitrogen allocated to reproductive function and maintenance in snails with a restricted food supply.

The trophic ecology of arctic char ( Salvelinus alpinus) and brown trout ( Salmo trutta) in Ellidavatn, a small lake in Southwest Iceland

In the lake Ellidavatn, southwest Iceland, fish samples were collected with gillnets of one mesh-size once or twice a month for two years. Stomach samples of 961 Arctic char and 429 brown trout were analysed. The annual diet of char consisted of chironomid larvae (31%), cladocerans Eurycercus lamellatus (19%), bivalves Pisidium spp. (16%), water snails Lymnaea peregra (15%), chironomid pupae (8%) and char eggs (5%) and that of trout consisted of sticklebacks (76%), salmonids (7%) and L. peregra (6%). The average percentage of indigestible plant remains and gravel in the stomach content was much higher for the char (14%) than trout (3%). There were large seasonal changes in the diet of char: char eggs were consumed in autumn, chironomid larvae mostly from autumn to spring, chironomid pupae in summer and E. lamellatus from summer to autumn. No seasonal changes in the diet of trout were seen. The diet overlap of char and trout was very low, usually about 10%, reaching a maximum of about 30% in late summer 1976 when the common diet was mainly E. lamellatus and chironomid pupae. The resource partitioning in Ellidavatn indicates that char are better adapted to preying on small benthic invertebrates than piscivorous trout. The segregation in the diet of the two species indicated competition for restricted food supply, which was also consistent with slow growth and low condition factor of char (0.8–1.0) and trout (1.0) in Ellidavatn. The prey of trout were two orders of magnitude larger than the prey of char which may explain why adult char grew more slowly (2 cm y −1) than adult trout (4 cm y −1) and reached sexual maturity at a smaller size (30 cm) than trout (40 cm).