Seasonal variation in the energy metabolism in an estuarine crab,Chasmagnathus granulata (Dana, 1851)

• 1.1. The effects of seasonal variation on the carbohydrate and lipid metabolism of the Chasmagnathus granulata were investigated.
• 2.2. Glycemia is high in winter and summer and low in spring and fall.
• 3.3. The glycogen content in the hepatopancreas and muscle is higher in fall and winter, and decreases during spring and summer.
• 4.4. The muscle lipids are higher in summer, and decrease during fall and winter whereas hepatopancreas lipids are higher except in the fall.
• 5.5. The crabs show change in the metabolic pattern of lipids and carbohydrates during the seasons of the year.

     

Variations of respiratory rate of Tisbe holothuriae humes (copepoda,harpacticoida) in relation to temperature,salinity and food type

• 1.1. The influence of temperature (14,19, 24°C), salinity (26,32, 38,44%.) and food type (artificial diets: Fryfood, Mytilus, Soya, Yeast, Spirulina) on the respiratory rate of Tisbe holothuriae has been studied.
• 2.2. Oxygen consumption decreased with decreasing temperature, but with a greater rate at supra- or subnormal salinities.
• 3.3. Multiple-regression analysis showed the quadratic effect of temperature and the linear effect of salinity to be the more important factors affecting respiration.
• 4.4. The food type also seems to exert an important effect on oxygen consumption.
• 5.5. A significant lowering of respiration was observed for all food tested when the animals were starved.

     

The rise in inosine monophosphate and l-lactate concentrations in muscle of live penaeid prawns (Penaeus japonicus,Penaeus monodon) stressed by storage out of water

• 1.1. This work aimed to establish why some species of prawns survived longer than others during simulated commercial shipment.
• 2.2. Metabolism of kuruma prawns, Penaeus japonicus, and black tiger prawns, P. monodon, stored for up to 24 hr in dry sawdust was studied by measuring concentrations of l-lactate, adenylate nucleotides and inosine monophosphate (IMP) in abdominal muscle.
• 3.3. When P. japonicus was stored in sawdust at 12°C the adenylate energy charge (AEC) did not fall and no lactate or IMP accumulated after 24 hr. However, the AEC fell in P. monodon stored at a temperature of 12°C and in P. japonicus stored at higher temperatures. When AEC fell below 0.5–0.6 there was an increase in muscle lactate and IMP concentration.
• 4.4. The results show that high concentrations of lactate and IMP in muscle tissue, at a given temperature, can be used to demonstrate that a prawn has been out of water for too long.

     

Dehydration does not influence the summer versus winter thermal adaptation changes in rabbits (oryctolagus cuniculus), living in natural photoperiod

• 1.1.|Resting metabolic rate of laboratory rabbits kept indoors is susceptible to seasonal fluctuations and is higher in winter than in summer.
• 2.2.|Thermoneutral zone of rabbits under these conditions may shift downwards in winter and upwards in summer.
• 3.3.|Both of these adjustments in thermoregulation seem to be related to the seasonally changing photoperiod.
• 4.4.|Dehydration does not influence these thermoregulatory adaptive changes.

     

Adenylate energy charge: a possible trophic index for management of oyster intensive aquaculture.

1. O. edulis and C. gigas both exhibit a seasonal variation in AEC with minimum values in summer. Two factors, food and temperature, were examined to explain these low summer values. 2. The AEC level varied with food level but a seasonal pattern was still observed. Two age groups of oysters were tested, giving a similar response. 3. The effect of temperature on the seasonal variations in AEC was confirmed by a significant correlation between AEC and temperature. This relationship allows us to calculate an AEC standard that only retains the trophic information. 4. Different trophic levels were identified in Marennes-Oléron Bay with AEC standard but growth rate was not related to them. So, AEC may inform on the carrying capacity of a given area but does not predict growth performances which will depend on other parameters.     

Adaptation to cadmium in three populations of the isopod Porcellio scaber

• 1.1. First-generation laboratory animals of three populations of the isopod Porcellio scaber, collected from a reference wood, a zinc smelter area and a lead mine site, were compared with respect to effects of Cd.
• 2.2. All populations reacted differently to Cd-contaminated food: increased Cd concentrations in the food resulted in decreased consumption and growth for the reference isopods; mine isopods were not affected by Cd and for the smelter animals Cd stimulated growth at an intermediate concentration.
• 3.3. Since Cd concentrations in the isopod did not differ between populations, adaptation is probably based on an increased detoxification capacity.
• 4.4. The assimilation of Cd did not affect the Cu or Zn content of the isopods although the adapted isopods regulated their Cu content on a lower level than reference isopods.

     

Characteristics of Crassostrea virginica crystalline style chitin digestion

• 1.1. Fundamental chitin digestion characteristics of Crassostrea virginica crystalline style were investigated.
• 2.2. Optimum temperature and pH were 34°C and 4.8. respectively.
• 3.3. The colloidal regenerated chitin (0.56mol/0.5 ml: GlcNAc equivalents) was saturating under all enzyme levels encountered.
• 4.4. There was no evidence of end product inhibition, even after 100 hr incubation.
• 5.5. Calculated K_m for the chitinase complex was 1.19mM when determined using a 30 min assay, but was only 0.70 mM when determined using a 4.6 hr assay.
• 6.6. Both K_m values are lower than reported for similar assays in other molluscs and for most bacteria.
• 7.7. Effect of substrate preparation on the kinetics are discussed.
• 8.8. Eight peaks of chitinase activity were resolved by DEAE-Fractogel ion exchange chromatography.

     

Growth and haematological response of sturgeon hybrids Russian sturgeon (Acipenser guldenstadti brandt) × beluga (Huso huso L.) to protein and lipid contents in the diet

• 1.1. Fingerlings of intergenious hybrid Russian sturgeon (Acipenser guldenstadti) × beluga (Huso huso) weighing 22 g reared in water with salinity 18 ppt were fed nine diets differing in protein and fat content.
• 2.2. The increase of dietary protein content (from 45 to 52%) improved the fingerlings growth rate, food and protein conversion efficiencies. No effect of further protein content increase to 60% was observed.
• 3.3. The increase of dietary fat content from 10 to 20% positively influenced all growth results.
• 4.4. The muscular lipid content increased following the increase in dietary fat due to accumulation of triacylglycerols.
• 5.5. Distinctive leucopenia in neutrophils and leucophilia in lymphocytes following dietary protein and fat content increase were observed.
• 6.6. It was concluded that within the analysed range of values the increase of dietary protein and lipid content improved the physiological status of sturgeon hybrid fingerlings.

     

The regulation of glucose 6-phosphate dehydrogenase from Dicentrarchus labrax (bass) liver

• 1.1. Kinetic constant values of the reaction catalyzed by bass liver glucose 6-phosphate dehydrogenase show to be modified between 10 and 40°C.
• 2.2. The Arrhenius plot between 10 and 50°C shows two slopes with different activation energies.
• 3.3. These results suggest a regulation of this enzyme by environmental temperature.
• 4.4. Kinetics of ATP inhibition were examined between pH 6.2 and 7.8: patterns and K_i values obtained are affected by the pH variation.
• 5.5. NADH is an effective inhibitor of bass glucose 6-phosphate dehydrogenase but this enzyme does not show NAD-linked activity.
• 6.6. Kinetics of pyridoxal 5′-phosphate inhibition have indicated the presence of a lysine in the catalytic site for NADP⁺.

     

Food deprivation induces differential changes in contents and microstructures of digestive tract and appendages in bluegill fish,Lepomis macrochirus

• 1.1. The digestive tract was compared with the tract appendages (caeca) in bluegill fish, Lepomis macrochirus in their response to short and long term food deprivation.
• 2.2. Fasting for 7 days resulted in 80% reduction of food content in the main tract, but only 40% reduction in appendages (caeca).
• 3.3. The intestine exhibited two different patterns of food distribution under fed and food deprived conditions.
• 4.4. The histopathological impact of starvation was more prominent on the intestine than on caeca.
• 5.5. These results suggest that digestive tract and appendages concommitantly conserve food during food scarcity, but appendages may offer advantages in retaining food longer, and in their greater resistance to starvation-induced effects.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Relationship of growth to SDA

• 1.1. The relationship of Specific Dynamic Action (SDA) to growth was examined in the supralittoral isopod Ligia pallasii using a seaweed diet fed at different rations.
• 2.2. Animals increased in live weight by 33% on an ad libitum or 100% diet and by 2% on a 20% ration over a 10-week period.
• 3.3. Weight-specific VO₂ was significantly higher in animals eating the 100% diet than in ones eating the 20% diet. Decline in VO₂ with time in animals on the 20% diet was probably due to poor health associated with a maintenance ration.
• 4.4. SDA per unit weight of food eaten was 18% higher in the 20% diet group than in the 100% one, and values remained constant over time in both groups.
• 5.5. k₁ growth efficiencies (production/consumption) were higher in animals on 100% ration than in ones on 20% ration. Efficiencies declined with time in both diet-groups and fell below zero in the 20% ration-group, coincidental with weight-loss in some of the animals.
• 6.6. Overall SDAs for the 10-week period were positively correlated with growth (r₂ = 0.77), but there was no way to separate this from amounts eaten as an effect on SDA.

     

Effects on growth and respiration due to the ingestion of the rapeseed meal glucosinolates in young larvae of Tenebrio molitor

• 1.1. We investigated the effects of the ingestion of naturally occurring glucosinolates in rapeseed meal on growth rate, metabolic efficiency and respiratory rate in larvae of the yellow mealworm, Tenebrio molitor L.
• 2.2. In our feeding studies, larvae were reared on one of seven different diets, including a whole ground wheat control diet and rapeseed meal from six rapeseed varieties. Dry weight gain of larvae and dry food assimilated were measured after 4 weeks of rearing, and the conversion of food into insect biomass was determined. The results may be explained by variations in the glucosinolates content of the diets.
• 3.3. The effect of glucosinolates on food consumption, larval growth, expired carbon dioxide, oxygen uptake and respiratory quotient were studied.
• 4.4. Glucosinolates did not reduce food assimilation or growth after 1 day of experimentation, but they caused some inhibition of respiratory exchanges and increased the RQ ratio.

     

Effects of acclimation temperature,season, and time of day on the critical thermal maxima and minima of the crayfish Orconectes rusticus

• 1.1. The critical thermal minima (CTMin) and maxima (CTMax) were determined for field-acclimatized and laboratory-acclimated crayfish (Orconectes rusticus) throughout 1984.
• 2.2. The CTMin and CTMax of field-acclimatized crayfish were seasonally adjusted by 9.7 C and 14.7 C respectively.
• 3.3. Seasonal variation in both tolerance regimes persisted in crayfish acclimated in the laboratory at 5 and 25°C for one week; however, no diel variation existed in either the CTMin or CTMax of laboratory-acclimated crayfish.
• 4.4. Integration of thermal acclimation of the CTMin and CTMax with seasonal conditioning may influence the functional capacities of this species when considered in relation to the seasonal ranges in stream temperature.

     

Elementary chemical composition of Tisbe holothuriae humes (copepoda: harpacticoida) as influenced by temperature,salinity and food type

• 1.1. The copepod Tisbe holothuriae was collected from the Saronicos gulf of Greece and cultured in the laboratory, under dif'erent combinations of temperature and salinity and as well as different types of food.
• 2.2. The content of C, H and N in females was measured.
• 3.3. As temperature increases and salinity declines from 38%, the content of C, H and N per individual decreases.
• 4.4. The type of food influences the carbon and hydrogen content per individual, while the nitrogen content is relatively constant.
• 5.5. The percentage content of C, H and N in females without egg sacs and females carrying their first newly formed egg sacs do not differ significantly

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Effects of temperature and acid stress on hatching,survival capacity,metabolism and postural reflexes in caenid mayflies (ephemeroptera)

• 1.1. Mortality was 100% at pH 3.5 over a temperature range of 10–30°C for embryos and nymphs of Caenis diminuta and C. hilaris.
• 2.2. Hatching success for both species was highest at pH values above 4.5.
• 3.3. Survival capacities were significantly higher at 20°C over a pH range of 4.0-7.2.
• 4.4. Oxygen consumption rates increase as a function of increasing temperature and reduced acidity.
• 5.5. Loss of the nymphal righting response was observed at pH 3.5. This response can be used as a behavioral assay for acid stress.

     

Temperature acclimation in respiratory and cytochrome c oxidase activity in common carp (Cyprinus carpio)

• 1.1. Common carp (Cyprinus carpio) exposed to experimental temperatures of 12, 18, 24, 30 or 36°C for a 4-week period were used to investigate the effect of temperature acclimation on the frequency of opercular movement (FOM), growth and cytochrome c oxidase (CCO) activity in heart, liver and muscle.
• 2.2. An exponential relationship between FOM and temperature after the first week (10₁₀ =1.76) disappeared after the second week.
• 3.3. The initially high FOM at temperatures of 30 or 36°C and the low FOM at 18 or 12°C changed over 4 weeks to approach the FOM of fish at 24°C.
• 4.4. This change in the relationship of FOM to temperature from highly dependent to independent appeared to be thermal compensation.
• 5.5. Heart and liver CCO activities were significantly affected by temperature, with the lowest activity at the approximate optimum temperature for growth, 24°C.
• 6.6. Highest CCO activities for heart and liver occurred at both the highest and lowest temperatures.
• 7.7. Among the three tissues, heart CCO activity was generally the highest and most affected by acclimation temperature.
• 8.8. Muscle tissue had the lowest CCO activity and was unaffected by temperature.
• 9.9. The high CCO activity at a cold acclimation of temperature 12°C was probably due to thermal compensation and the high activity at 36°C may have been a result of thermal stress.

     

The effects of artificial solar radiation on wind-stressed tufted titmice (Parus bicolor) and Carolina chickadees (Parus carolinensis) at low temperatures

• 1.1. Changes in metabolic rates and behavior were observed in tufted titmice (Parus bicolor) and Carolina chickadees (Parus carolinensis) exposed to varying conditions of artificial solar radiation, wind, and temperature in a wind tunnel experiment.
• 2.2. During the wind-on condition, both species showed a significant decrease in mean metabolic rates in the high radiation treatments when compared to the low radiation treatments (P < 0.05).
• 3.3. Titmouse orientation, posture and level of activity were significantly affected by radiation and wind conditions.
• 4.4. Metabolic rates observed in the wind tunnel treatments without wind and at low radiation did not significantly differ from similar standard metabolic (black box) treatments (P > 0.05).
• 5.5. Activity levels did not appear to directly affect metabolic rates observed in the wind tunnel treatments.

     

Morphometry and composition of red drum otoliths: Changes associated with temperature,somatic growth rate,and age

• 1.1. Size and composition of sagittal otoliths from red drum, Sciaenops ocellatus (Sciaenidae), reared at various constant temperatures were compared with otoliths from wild-caught fish.
• 2.2. Uncoupling of otolith growth and somatic growth in laboratory-reared fish was evident in otolith length, area, volume, weight, density, and organic fraction.
• 3.3. Fish grown at low temperatures had significantly smaller and less dense otoliths having a greater organic content than fish of the same size grown at higher temperatures.
• 4.4. Changes in inorganic elements were poorly related to temperature in laboratory-reared fish.
• 5.5. The effect of temperature on otolith elemental composition was small relative to the effects of age and its associated physiological changes.

     

Investigation of seasonal variations in cow serum retinol and β -carotene by high performance liquid chromatographic method

• 1.1. High performance liquid chromatography (HPLC) was used to determine β-carotene and retinol in cow serum.
• 2.2. Two groups of state and private farm cows (Groups 1 and 2) were used to assess seasonal variation when different food sources were fed to cows on serum β -carotene and retinol concentrations.
• 3.3. Mean serum concentrations of β-carotene and retinol from October to April in both Groups 1 and 2 cows were lower (P < 0.05) than in the other months when the cows were fed various combination of maize silage, alfalfa and carrot residues and grass hay, respectively.
• 4.4. Mean serum β-carotene and retinol concentrations in June and July were higher (P < 0.05) than in other months when the cows were in pasture.
• 5.5. Mean serum β-carotene and retinol concentrations in May, August and September were lower (P < 0.05) than in June and July and higher (P < 0.05) than in other months when a lesser amount of green pasture was available to the cows.
• 6.6. There was a seasonal variation (P < 0.05) in serum β -carotene and retinol concentrations. When the carotene intake is very high, conversion of β -carotene to retinol decreases. Mean monthly serum β -carotene and retinol concentrations showed that combination of alfalfa hay and maize silage, and grass hay and carrot residues can maintain adequate serum β-carotene and retinol concentrations during the dry season.

     

Strontium-calcium concentration ratios in fish otoliths as environmental indicators

• 1.1. External and internal examinations of otoliths in fishes for macrostructure and microstructure has demonstated yearly, daily and population rhythmic patterns.
• 2.2. Chemical analyses (atomic absorption) of otolith carbonate from reared Fundulus heteroclitus for strontium-calcium concentration ratios demonstrated changes in chemistry related to temperature.
• 3.3. Microprobe analyses made it feasible to interpret almost daily changes in temperature to provide the temperature history of an individual fish.
• 4.4. A combination of microprobe analyses and daily increment analyses of otoliths can provide a life history profile for individual fish and can provide information on the environmental history of each fish.
• 5.5. Such information is vital to our understanding of the processes underlying recruitment and growth rates, and would make it possible to link growth and mortality rates to environmental occurrences.