Effect of experimental conditions on the stomach evacuation of Coregonus lavaretus L.

The gastric evacuation of juveniles of Coregonus lavaretus L. fed on living Daphnia pulicaria was investigated. Three successive stages of stomach evacuation were observed when one meal per day was given: (i) a lag phase between the end of food intake and the beginning of stomach evacuation, (ii) a linear reduction of stomach content, (iii) a long residence time for food relics in the stomach. The initial stomach content and the stomach evacuation time are correlated positively. The stomach content increased during feeding when three meals day ⁻¹ were provided and it decreased when no food was available. During the course of an experiment the highest stomach content found increased with increasing daly ration. Excess feeding resulted in a low stomach content similar to that found with rations about 30–50% of the maximum daily food intake. Therefore the daily food intake cannot be determined by the single parameter of stomach content alone. Identical initial stomach contents showed significantly higher stomach evacuation rates under three meals day⁻¹ conditions than under one meal day⁻¹ conditions.     

Dietary molar ratios of phytate: Zinc and millimolar ratios of phytate × calcium: Zinc in South Koreans

The zinc nutritional status in south Koreans was established by evaluation of zinc, calcium and phytate intakes, the molar ratio of phytate: zinc, and the millimolar ratio of phytate × calcium: zinc. The intakes of iron and magnesium were also estimated. Sampling was designed so that it was representative of the national population. Two-day food records were used for the calculation of nutrient intakes, using food consumption data from the 1995 National Nutrition Survey (’95NNS) for South Korea. Daily intakes of zinc and calcium were estimated to be 10.1 mg/d and 426.5 mg/d, respectively, and those of iron and magnesium were 15.2 mg/d and 268.0 mg/d, respectively. The estimated daily phytate intake was 1676.6 mg/d. The ratio of phytate: zinc was 15.9 mol/d and that of phytate × calcium: zinc was 168.9 mmol/d. The ratio in millimoles per 4.2 MJ (1000 kcal) of phytate × calcium: zinc was 91.8. The major food groups for zinc intake were meat, poultry and their products (43%), and cereals and grain products (18%). Sixty-two percent of zinc was from animal food sources. Cereal and grain products supplied most of the phytate intake (46%) followed by seasonings, fruits, and legumes and their products. The major food source of phytate was rice (39%). The results of the study raise concern about the suboptimal zinc status in relation to the Western diet.     

Nahrungsaufnahme,Stoffumsatz und Energiehaushalt des marinen HydroidpolypenClava multicornis

Clava multicornis Forskål (Cnidaria, Hydrozoa) from the North Sea was cultured under a variety of environmental conditions, and quantitative aspects of the following processes examined: food intake, growth, oxygen consumption, losses of material, and food conversion. The experiments were conducted in sea water (salinity 32 ‰) at different constant temperature levels (6°, 11° and 16° C) and different daily food rations. The polyps were fed living larvae of the brine shrimpArtemia salina. Daily rations ranged from 2.3 % (6° C) to 19.0 % (16° C) of the dry weight of the polyp colonies. The food ration essential for minimum growth increased with the test temperature. The calorific value of theArtemia larvae was 5854 cal per g organic dry substance. The calorific values of the colonies ofClava multicornis increased at all 3 test temperatures with ascending daily food rations; they ranged from 5367 to 6003 cal per g organic dry substance. Colony growth was determined in 3 different ways: by measuring the increase in polyp number, the length increase of all polyps of a given colony, and the increase of the dry weight of the organic substance of a given colony. Growth was exponential in all 3 cases. The lowest test temperature, or small daily rations, caused slow growth; the highest temperature, or large daily rations, resulted in rapid growth. Oxygen consumption of individual colonies was measured at 16° C and 3 different daily rations; the colonies showed the same intensity of respiration at all 3 daily rations. A colony of 1.5 mg organic dry substance respired 0.107 ml oxygen per 24 hours, a colony of 5.0 mg, 0.269 ml oxygen. At 11° and 16° C gonophores developed well and were counted; at 6° C no gonophores were observed. The amount of the excrement discharged byC. multicornis at 16° C increased from 26.0 % of the food eaten (minimum daily ration) to 39.3% (maximum daily ration). Gross efficiency increased with falling temperature and rising daily ration. At 16° C, net efficiency increased with rising daily ration. On the basis of the data obtained for gross efficiency, oxygen consumption and excrementation, an energy budget was made up.     

Effect of feeding frequency on growth, feed utilization, and size variation of juvenile gibel carp (Carassius auratus gibelio)

Juvenile (3.0 ± 0.2 g) gibel carp (Carassius auratus gibelio) were fed to satiation for 8 weeks to investigate the effect of feeding frequency on growth, feed utilization and size variation. Five feeding frequencies were tested: two meals per day (M2), three meals per day (M3), four meals per day (M4), 12 meals per day (M12) and 24 meals per day (M24). The results showed that daily food intake increased significantly with the increase in feeding frequency and there was no significant difference between daily food intakes in M12 and M24 treatments. Growth rate, feed efficiency increased significantly with increasing feeding frequencies. Size variation was not affected by feeding frequency. Apparent digestibility of dry matter was not influenced by feeding frequency, while apparent digestibility of protein and energy increased significantly at high feeding frequencies. The feeding frequency had no significant effect on the moisture, lipid, protein, or energy contents of gibel carp, while the ash content decreased with increased feeding frequency. It was recommended that 24 meals per day was the optimal feeding frequency for juvenile gibel carp.     

Daily fat consumption by the population of Warsaw]

Fat intake with the diet has been assessed within screening Pol-MONICA--Warsaw Project in randomly selected sample of Warsaw inhabitants aged between 35 and 64 years. Altogether 2571 individuals have been screened. Fat intake in daily diet has been estimated by the 24-hour recall technique. In men, fat intake covered 38.4% of the total energy supply with the diet whereas in female population - 37.7%. Mean contribution of SFA and P/S ratio in both sex groups have been 15.8% and 0.285, respectively. Daily cholesterol intake has been 641 mg (224 mg/1000 kcal) in male and 456 mg (227/1000 kcal) in female population. These values did not change significantly with the age of the screened individuals. Such a diet may be considered atherogenic.     

Dietary Calcium Intake Is Associated With Less Gain in Intra‐Abdominal Adipose Tissue Over 1 Year

Calcium intake is reported to enhance weight loss with a preferential loss in trunk fat. Discrepant findings exist as to the effects of calcium intake on longitudinal changes in total fat mass and central fat deposition. Therefore, the purpose of this study was to determine associations between dietary calcium intake and 1‐year change in body composition and fat distribution, specifically intra‐abdominal adipose tissue (IAAT). A total of 119 healthy, premenopausal women were evaluated at baseline and 1 year later. Average dietary calcium was determined via 4‐day food records. Total fat was determined by dual‐energy X‐ray absorptiometry (DXA) and subcutaneous abdominal adipose tissue (SAAT) and IAAT by computed tomography. Over the study period, participants' reported daily calcium and energy intakes were 610.0 ± 229.9 mg and 1,623.1 ± 348.5 kcal, respectively. The mean change in weight, total fat, IAAT, and SAAT was 4.9 ± 4.4 kg, 5.3 ± 4.0 kg, 7.7 ± 19.5 cm², and 49.3 ± 81.1 cm², respectively. Average calcium intake was significantly, inversely associated with 1‐year change in IAAT (standardized β: ?0.23, P < 0.05) after adjusting for confounding variables. For every 100 mg/day of calcium consumed, gain in IAAT was reduced by 2.7 cm². No significant associations were observed for average calcium intake with change in weight, total fat, or SAAT. In conclusion, dietary calcium intake was significantly associated with less gain in IAAT over 1 year in premenopausal women. Further investigation is needed to verify these findings and determine the calcium intake needed to exert beneficial effects on fat distribution.     

Dietary zinc intake of a group of longstay mentally handicapped women some bioavailability considerations

Dietary factors affecting zinc bioavailability were evaluated according to their relative distribution in the individual daily meals making up the basic diet of 17 institutionalized, mentally handicapped adult women. Mean intake values of zinc, phytate, nonstarch polysaccharides (NSP), calcium, protein, and energy were calculated from a dietary survey of 7 consecutive days, which also served to obtain values for the two zinc bioavailability predictor formulas, phytate/Zn millimolar ratio and [Ca] [phytate]/[Zn][energy] ratio. Mean daily zinc intake was 8.5 ±1.8 mg, with noon and evening meals accounting for the highest contribution to this value (45% and 35%, respectively), whereas breakfast meals’ contribution was 16%. The mean protein intake was 55 ±13 g, with noon and evening meals being the major contributors to total daily intake (42% and 38%, respectively). Breakfast meals accounted for 77% of daily phytate intake, giving a respective phytate/Zn millimolar ratio of 20.4 ±7.6 and a [Ca][phytate]/[Zn][energy] ratio of 336 ±127 mmol/Mcal. Values for both ratios based on noon and evening meals were negligible in comparison. The mean daily NSP intake was 9.8 ±4.2 g, with 53% of total daily intake supplied from breakfast meals, whereas noon and evening meals accounted for 30% and 14%, respectively. The results, while suggesting that zinc bioavailability is unlikely to be adversely affected, indicated that dietary fiber intake levels are probably inadequate, particularly in view of the nonambulant condition and low physical activity prevalent in such individuals, who may, as a consequence, be susceptible to health disorders associated with impaired bowel function and constipation.     

Comparisons of energy intake and energy expenditure in overweight and obese women with and without binge eating disorder

The purpose of this study was to determine whether there are differences in energy intake or energy expenditure that distinguish overweight/obese women with and without binge eating disorder (BED). Seventeen overweight/obese women with BED and 17 overweight/obese controls completed random 24-h dietary recall interviews, and had total daily energy expenditure (TDEE) assessed by the doubly labeled water (DLW) technique with concurrent food log data collection. Participants received two baseline dual-energy X-ray absorptiometry (DXA) scans and had basal metabolic rate (BMR) and thermic effect of food (TEF) measured using indirect calorimetry. Results indicated no between group differences in TDEE, BMR, and TEF. As in our previous work, according to dietary recall data, the BED group had significantly higher caloric intake on days when they had binge eating episodes than on days when they did not (3,255 vs. 2,343 kcal). There was no difference between BED nonbinge day intake and control group intake (2,233 vs. 2,140 kcal). Similar results were found for food log data. Dietary recall data indicated a trend toward higher average daily intake in the BED group (2,587 vs. 2,140 kcal). Furthermore, when comparing TDEE to dietary recall and food log data, both groups displayed significant under-reporting of caloric intake of similar magnitudes ranging from 20 to 33%. Predicted energy requirements estimated via the Harris-Benedict equation (HBE) underestimated measured TDEE by 23-24%. Our data suggest that increased energy intake reported by BED individuals is due to increased food consumption and not metabolic or under-reporting differences.     

Growth, daily ration, and gastric evacuation rates of milkfish (Chanos chanos) fed supplemental diet and natural food

Growth, daily ration, and gastric evacuation rates of milkfish ( Chanos chanos ) that fed on natural food and supplement diet were evaluated. Milkfish fingerlings (5.5g) were stocked at 1.5 fish/m² in ten 12 m² concrete tanks layered with 15-cm thick earthen bottoms. All tanks were regularly fertilized (16–20–0 and chicken manure) to maintain natural food production; 4 of the tanks additionally received a supplemental diet containing 34.3% protein and 4290 kcal/kg gross energy. Estimates or daily ration (based on dry weight of stomach contents) were calculated using the E lliot and P erson (1978) and E ggers 1977) models. Gastric evacuation rate was lower in fish that fed on natural food (1.57) compared to fish fed a supplemental diet (1.79). Consequently, the lower rate resulted in lower food intake and slower fish growth. When fish were provided a high quality supplemental diet, daily rations for fingerlings (35 g) to marketable size (116 g) ranged approximately from 0.60 to 19.68 kcal/fish/day. The deviation in daily ration (kcal/fish/day) from the above estimates may indicate the insufficient quantity of dietary energy taken by fish from natural food alone, which could be provided by supplemental diet.     

Seven Dietary Minerals (Ca, P, Mg, Fe, Zn, Cu, and Mn) and Their Relationship with Blood Pressure and Blood Lipids in Healthy Adults with Self-Selected Diet

The purpose of this study is to evaluate the dietary intakes of calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn) and investigate their correlation with blood pressure and blood lipids. Targeting 258 healthy men and women, blood pressure was measured, and blood samples were collected to analyze serum lipids, and then the intakes of seven minerals were assessed through a food intake survey for 3 days using a 24-h recall method. The average age of the men and women was 49.55 and 49.19, respectively. The daily energy intake of the men was 1,830.57 kcal, which was significantly higher than that of women, 1,476.23 kcal (p?<?0.001). The mineral intake of the subjects was as follows: 450.95 mg/day for Ca, 915.24 mg/day for P, 279.23 mg/day for Mg, 12.60 mg/day for Fe, 8.25 mg/day for Zn, 1.23 mg/day for Cu, and 4.22 mg/day for Mn. These accounted for 63.83, 130.76, 90.74, 129.75, 97.50, 154.49, and 113.50 % of adequate intake or the recommended intake of each mineral, respectively. Subjects who did not satisfy the estimated average requirement were 74.00 % for Ca, 63.18 % for Mg, and 41.86 % for Zn. After adjusting for age, sex, BMI, and energy intake, Mg intake had a negative correlation with systolic blood pressure (SBP), and Cu intake had a significant negative correlation with SBP and diastolic blood pressure (DBP). Also, Mn intake was negatively correlated with DBP, serum total cholesterol, and triglycerides. Thus, it is concluded that the dietary intakes of Mg, Cu, and Mn may play an important role in controlling blood pressure and lipids in Korean adults.     

武威市结核病患者膳食多样化水平及营养素摄入状况调查

目的：了解武威市结核病（TB）患者膳食多样化水平及各类营养素摄入情况。方法：选取武威市结核患者826名,由统一培训的结核病防治科医生,进行面对面的问卷调查,应用食物频率表收集调查对象消费的食物种类;24小时膳食回顾法收集调查对象膳食营养素摄入情况。采用9大类食物评价膳食多样化,每周食用一种食物计1分,最多为9种食物计9分。结果：膳食多样化评分（DDS）结果显示,分值为7分及以上的人群达到了51．5％,其中得分7分的人群达到总人数的33.3％,有48．5％不足7分,即没有达到膳食多样化。鱼虾类和豆类消费率最低,分别仅为6．7％和44．3％。能量及营养素分析结果显示：结核病患者每日能量和蛋白质摄入量分别为1563．9kcal和60．6g,仅达到推荐摄入量（RNI）的65．16％和80．67％,除了铁、锰、磷元素的摄入量达到了RNI之外,其余维生素及矿物质每日摄入量均不足,尤以视黄醇（122．2μg）和钙（224．7mg）最低,分别为RNI的15．28％和28．09％。膳食纤维、抗坏血酸和核黄素的摄入水平均不足RNI的50％。结论：武威市结核病患者膳食结构不均衡。建议积极改善营养、调整膳食结构,加强膳食营养相关知识的健康宣教,有效防治结核病。     

Energy expenditure of elite female runners measured by respiratory chamber and doubly labeled water.

To determine whether female athletes have unusually low energy requirements as suggested by many food intake studies, energy expenditure (EE) and intake were assessed in nine elite distance runners [26 +/- 3 (SD) yr, 53 +/- 4 kg, 12 +/- 3% body fat, and 66 +/- 4 ml.kg-1.min-1 maximal O2 uptake]. Subjects were admitted to a metabolic ward for 40 h during which 24-h sedentary EE was measured in a respiratory chamber. Free-living EE was then assessed by the doubly labeled water method for the next 6 days while the women recorded all food intake, daily body weight, and training mileage (10 +/- 3 miles/day). Energy intakes estimated from free-living EE (2,826 +/- 312 kcal/day) and body weight changes (-84 +/- 71 g/day) averaged 221 +/- 550 kcal/day in excess of those calculated from food records (2,193 +/- 466 kcal/day). The energy cost of training (1,087 +/- 244 kcal/day) was calculated as the difference between free-living EE and 24-h EE in the respiratory chamber (1,681 +/- 84 kcal/day) corrected for the thermic effect of food of the extra energy intake. These data do not support the hypothesis that training as a distance runner results in metabolic adaptations that lower energy requirements in women.     

Manganese,copper, and zinc in cerebrospinal fluid from patients with multiple sclerosis

The concentrations of manganese, copper, and zinc in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS) and patients with no known neurological disease (control group) were measured. Manganese and copper levels were determined by two different analytical methods: atomic absorption spectrometry (AAS) and high-resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS), whereas zinc levels were determined by HR-ICP-MS only. Manganese levels (mean±SEM) were significantly decreased in the CSF of MS patients (1.07±0.13 μg/L, ICP-MS; 1.08±0.11 μg/L, AAS) compared to the levels in the control group (1.78±0.26 μg/L, ICP-MS; 1.51±0.17 μg/L, AAS). Copper levels were significantly elevated in the CSF of MS patients (10.90±1.11 μg/L; ICP-MS, 11.53±0.83 μg/L, AAS) compared to the levels in the control group (8.67±0.49 μg/L, ICP-MS; 9.10±0.62 μg/L, AAS). There were no significant differences between the CSF zinc levels of MS and control patients. The physiological basis for the differences in manganese and copper concentrations between MS patients and controls is unknown, but could be related to alterations in the manganese-containing enzyme glutamine synthetase and the copper-containing enzyme cytochrome oxidase.     

Dietary Exposure to Lead and Cadmium in Yugoslavia

Abstract

Lead exposure still represents a matter of health concern especially in Yugoslavia. To assess the exposure of normal urban population to lead and cadmium through food, a preliminary monitoring was performed on a small group of urban population. Lead, cadmium and some essential elements (calcium, zinc, iron, copper and manganese) were analysed in collected duplicate diet samples and compared to similar population in Sweden. We found that dietary exposure to lead and cadmium is similar to other countries although Yugoslav urban population is exposed to much higher concentrations of lead in air than in cities of developed countries, due to high lead in gasoline. However, daily intake of some essential elements was significantly lower.

Also populations living around lead smelters in various parts of Yugoslavia are still exposed to elevated environmental lead and cadmium levels. To assess the exposure of the population living in this area, a cumulative long-term exposure to lead was determined by measuring lead in deciduous teeth. Concentrations of lead and cadmium in vegetables, soil and meals from the same region were also analysed. Values obtained for lead and cadmium in food products grown in exposed and control area were found to be related to respective concentrations of these elements in soil as well as to the distance from the smelter. Meals prepared in this region show the same trend, revealing very high intake particularly of lead.

The influence of nutritional factors, i.e. dietary calcium on lead metabolism, was also studied. Blood lead concentration was determined in two groups of peasant women living in two regions with different dietary calcium intake. Lower blood lead values were found in the higher dietary calcium intake region.     

Prevalence of gallstones and risk factors in Caucasian women in a rural Canadian community.

The prevalence of gallstones and gallbladder disease was studied in a rural Caucasian population. All the women aged 15 to 50 years were asked to complete a questionnaire, undergo cholecystography and keep a food record for 4 consecutive days. The gallbladder status was assessed in 73%. The prevalence of gallstones in this population, 167/1000, was considerably higher than that reported in the Framingham study (59/1000) but was not significantly different from that recently found in Micmac Indian women living nearby in Canada (211/1000). In contrast to all the other studies in Caucasian women, this study showed the prevalence of gallstones to peak between the ages of 30 and 39 years. The risk factors, controlled for age, were found to be obesity, a narrow range of daily energy intake, a low daily calcium intake and limited activity. Discriminant analysis showed that skinfold thickness and range of daily energy intake or all measures of obesity together correctly separated the persons with gallstones from those without.     

Consumption of Calcium-Fortified Cereal Bars to Improve Dietary Calcium Intake of Healthy Women: Randomized Controlled Feasibility Study

Calcium is an important structural component of the skeletal system. Although an adequate intake of calcium helps to maintain bone health and reduce the risk of osteoporosis, many women do not meet recommended daily intakes of calcium. Previous interventions studies designed to increase dietary intake of women have utilized primarily dairy sources of calcium or supplements. However, lactose intolerance, milk protein allergies, or food preferences may lead many women to exclude important dairy sources of dietary calcium. Therefore, we undertook a 9 week randomized crossover design trial to examine the potential benefit of including a non-dairy source of calcium in the diet of women. Following a 3 week run-in baseline period, 35 healthy women > 18 years were randomized by crossover design into either Group I or Group II. Group I added 2 calcium-fortified cereal bars daily (total of 400 mg calcium/day) (intervention) to their usual diet and Group II continued their usual diet (control). At the end of 3 weeks, diets were switched for another 3 weeks. Intakes of calcium and energy were estimated from 3-day diet and supplemental diaries. Wilcoxon signed-rank tests were used for within group comparisons and Mann Whitney U tests were used for between group comparisons of calcium and energy intake. Dietary calcium was significantly higher during intervention (1071 mg/d) when participants consumed 2 calcium-fortified cereal bars daily than during the baseline (720 mg/d, P <0.0001) or control diets (775 mg/d, P = 0.0001) periods. Furthermore, the addition of 2 calcium-fortified cereal bars daily for the 3 week intervention did not significantly increase total energy intake or result in weight gain. In conclusion, consumption of calcium-fortified cereal bars significantly increased calcium intake of women. Further research examining the potential ability of fortified cereal bars to help maintain and improve bone health of women is warranted.

Trial Registration

ClinicalTrials.gov NCT01508689     

Food insecurity is not associated with lower energy intakes

We examined the association between food insecurity and total daily energy intakes in American men and women. We estimated the number of daily snacks and meals consumed by individuals in different food security categories. Also, we calculated the energy contribution, energy density, and food group sources of those snacks and meals. Using the 1999-2002 National Health and Nutrition Examination Survey (NHANES), we examined the Food Security Survey Module (FSSM) and dietary information from the 24-h recall. Differences in energy intakes between groups were not significant. Women who were food insecure without hunger (FIWOH) and food insecure with hunger (FIWH) had significantly fewer meals than food secure (FS) women. The energy contribution of each meal and the total energy contributed from snacking were both significantly greater for FIWOH women than for FS women. The number of meals was significantly lower whereas the daily number of snacking occasions and the total energy from snacking were significantly increased for FIWOH men relative to FS men. FIWOH men consumed snack foods that had significantly lower energy density than those consumed by FS men. Among men and women, the major sources of meal energy were the grain group, the meat, poultry, and fish group, and the sugar, sweets, and beverages group whereas the major source of snacking energy was the sugar, sweets, and beverages group. Total energy intakes were not different for FI individuals; however, their meal and snack behaviors were different. Focusing solely on total energy intake would miss important consequences of food insecurity.     

Serotoninergic Manipulation,Meal-Induced Satiety and Eating Pattern: Effect of Fluoxetine in Obese Female Subjects

Twelve nondepressed healthy female obese subjects (BMI > 30kg/m²) took part in a study which conformed to a double-blind randomized crossover design. Each subject acted as her own control across 2 weeks of treatment with either 60 mg of the 5-HT reuptake inhibitor fluoxetine or matching placebo. On days 7 and 14 of both treatment phases subjects were provided with fixed energy lunch meals high in either CHO or fat. The effect of these meals on satiety during the fluoxetine and placebo phases was assessed by a battery of procedures. Subjects felt less hungry after consuming the high CHO meal than after consuming the high-fat meal. They also felt less hungry when taking fluoxetine than when taking the placebo. Analysis of energy intake from the test meal revealed a main effect of prior lunch meal type (high CHO or high fat) and a main effect of drug treatment. Subjects consumed an average of 574 kcal following the high CHO meal compared to 689 kcal following the high-fat meal. Subjects also consumed an average of 532 kcal when taking fluoxetine compared to 730 kcal when taking the placebo. Fluoxetine did not exert any significant effects on macronutrient selection. Mean daily energy intake, calculated from food diary records, was 1881 kcal when subjects were taking the placebo compared to 1460 kcal when taking fluoxetine (a reduction of 22.4%). Fluoxetine treatment produced a significant weight loss of 1.97 kg over the two weeks of treatment compared to a weight loss of only 0.04 kg on placebo.     

Effect of spawning number and ration on reproductive performance of the batch-spawning three-spined stickleback Gasterosteus aculeatus

An experiment quantified the effect of food ration and spawning number on the breeding season reproductive performance of batch-spawning, female three-spined sticklebacks Gasterosteus aculeatus . Individually housed females were maintained on fixed rations of 2, 4, 8 or 16% of their initial postspawning mass of live enchytraeid worms from immediately after their first spawning until they ceased spawning. Number of spawnings correlated positively with ration. Total breeding season reproductive investment (total wet mass of eggs produced as a percentage of initial postspawning female mass) ranged from 38% at the 2% ration to 147% at the 16% ration. At the lower rations, postspawning mass, batch fecundity and wet and dry masses of the batch declined over successive spawnings, with the rate of decline inversely related to ration. At the highest ration, there was no decline in batch fecundity and postspawning mass increased over successive spawnings. Mean reproductive investment per inter-spawning interval was higher at the highest ration, but at all rations declined over successive spawnings. Mean reproductive effort per inter-spawning interval (wet mass of eggs spawned as a percentage of the wet mass of food consumed over the inter-spawning interval) was inversely related to ration. At the higher rations, reproductive effort showed no trend over successive spawnings. Neither spawning number nor ration had a systematic effect on egg diameter, wet mass per egg, dry mass per egg or total lipid content of the eggs. If the rate of food intake was insufficient, although batch fecundity declined, the main adjustment was a reduction in the number of spawnings in the breeding season.     

Daily ration of juvenile Coregonus lavaretus (L.) fed on living zooplankton

Juvenile whitefish, Coregonus lavaretus (L.), wet weight 0.04 to 5.2 g, from Lake Constance were kept at 10, 12 and 16° C water temperature, respectively and fed with living zooplankton. The experimental duration lasted 72 to 120 h. Daily rations were defined as the amount of zooplankton remaining subtracted from the amount of zooplankton added after a 24 h interval. The mortality of the zooplankton was determined in parallel experiments without fish. Relative daily ration (zooplankton weight/fish weight) v. fish weight increased up to a fish dry weight of approximately 0.12 g and then decreased steadily. The maximum daily ration was about 270% of fish body wet weight (wet/wet) corresponding to 75% of body dry weight (dry/dry), respectively. In fishes of a dry weight higher than 0.12 g (wet weight 0.65 g) a significant difference in food intake was found between 12 and 16° C. The specific growth rate ranged from nearly 0 up to 33% per day. No correlation was found between daily ration and specific growth rate.