Heat production of fish: A literature review

• 1.1. Results of investigations on direct calorimetry and simultaneous measurements of oxygen consumption and carbon dioxide and ammonia production of fish are summarized.
• 2.2. By means of indirect calorimetric formulae, the heat production and the protein, carbohydrate and fat oxidation are calculated from the oxygen consumption and carbon dioxide and ammonia production.
• 3.3. The lowest heat production values are obtained by long-term monitoring of groups of fish during darkness and under fasting conditions.
• 4.4. It is concluded that the heat production of standard metabolism at 20°C is 700J/hr/MW (MW = metabolic weight, kg^0.85).

     

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.

     

Respiratory mechanisms and metabolic adaptations of an intertidal crab,Chasmagnathus granulata (Dana, 1851)

• 1.1. The ventilatory mechanism, gill area, sites of oxygen uptake, oxygen consumption and activity of a crab from south Brazil, Chasmagnathus granulata, were investigated.
• 2.2. The oxygen uptake seems to be restricted to the gill lamellae.
• 3.3. The gill area varies with the wet body weight, being relatively higher in smaller animals. There is not a significative reduction of the gill area in relation to species of the infralittoral zone.
• 4.4. C. granulata presents a mechanism for recirculating the water of its branchial chamber when exposed to atmospheric air.
• 5.5. The oxygen consumption and activity are reduced when the animals are exposed to atmospheric air. The reduction in the oxygen consumption may be related to the poorly adapted respiratory system, while the decrease in activity may be a mechanism for saving energy during this hypoxic period.

     

Effect of eyestalk ablation on oxygen consumption of callinectes similis exposed to salinity changes

• 1.1. The effect of eyestalk ablation on preadults of Callinectes similis exposed to a constant salinity (30%.) and to simulated tidal changes in salinity (30-11 to 30%.) were measured.
• 2.2. In constant salinity, crabs showed a persistent respiratory rhythm, with a maximum oxygen consumption during the day. Under these conditions, ablation significantly increased the respiratory rate but not the rhythm.
• 3.3. In variable salinities, the highest respiratory rates occurred in salinities of 11 and 16%. during the night. In these crabs, ablation of eyestalks and subsequent injection of eyestalk extracts did not alter the respiration rate rhythm.
• 4.4. The circadian rhythm is controlled by the periodicity of environmental changes instead of the influence of eyestalk hormones.
• 5.5. Regulation of metabolism in C. similis associated with osmoregulation involves other neurosecretory organs.

     

Equilibria and kinetic of oxygen and carbon monoxide binding to the haemoglobin of the South American lungfish,Lepidosiren paradoxa

• 1. The haemoglobin of the South American lungfishLepidosiren paradoxa has a single component.
• 2. The equilibria of this respiratory protein with oxygen have been investigated both in the blood and with the purified haemoglobin. There is a substantial, normal, alkaline Bohr effect and marked sensitivity to organic phosphates in the haemoglobin solutions.
• 3. Studies on the pH dependence of the kinetics of oxygen dissociation can be interpreted in terms of a normal Bohr effect.
• 4. The kinetics of combination of carbon monoxide have an unusual pH dependence.
• 5. These findings are discussed in terms of the two-state model of Monodet al. (1965)

     

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.

     

Social facilitation of reduced oxygen consumption in Mus musculus and Meriones unguiculatus

• 1.1. The short-term resting rates of oxygen consumption of laboratory white mice (Mus musculus) and Mongolian gerbils (Meriones unguiculatus) were measured by closed system manometry.
• 2.2. Metabolic rates of animals tested individually were compared to those of huddled trios and trios in which the animals were tested simultaneously but prevented from physical contact (separated trios) at temperatures ranging from 9–25° C.
• 3.3. Rates of increase of weight-specific resting metabolism were greatest for animals tested individually.
• 4.4. There was no significant difference in the rates of increase of oxygen consumption between huddled and separated trios in cither species.

     

Facultative aestivation in a tropical freshwater turtle Chelodina rugosa

• 1.1. Chelodina rugosa dug from aestivation sites at the end of the dry season were immediately alert and well coordinated.
• 2.2. Compared with non-aestivating animals, aestivating turtles had 20% higher plasma osmotic pressure and 7% higher sodium. Coupled with a small, but significant weight gain upon return to the water, this suggested the occurrence of minor dehydration in aestivating animals.
• 3.3. Plasma lactate levels of aestivating animals were low, averaging 1.99 mmol/l, consistent with aerobic rather than anaerobic metabolism having sustained their long period under ground.
• 4.4. No evidence was seen of dramatic physiological specialization. Aestivation in this species is interpreted as a primarily behavioural adaptation, made possible by typically reptilian abilities to tolerate a wide range in plasma electrolytes and to survive long periods without feeding.

     

Effects of the nonsteroidal anti-inflammatory drug piroxicam on energy metabolism in the perfused rat liver

• 1.1. The actions of piroxicam, a nonsteroidal and noncarboxylic anti-inflammatory drug, on the metabolism of the isolated perfused rat liver were investigated. The main purpose was to verify if piroxicam is also active on glycogenolysis and energy metabolism, as demonstrated for several carboxylic nonsteroidal anti-inflammatories.
• 2.2. Piroxicam increased oxygen consumption in livers from both fed and fasted rats.
• 3.3. Piroxicam increased glucose release and glycolysis from endogenous glycogen (glycogenolysis).
• 4.4. Gluconeogenesis from lactate plus pyruvate was inhibited.
• 5.5. The action of piroxicam on oxygen consumption was blocked by antimycin A, but not by atractyloside.
• 6.6. The action of piroxicam in the perfused rat liver metabolism seems to be a consequence of its action on mitochondria.
• 7.7. It can be concluded that inhibition of energy metabolism and stimulation of glycogenolysis are not specific properties of carboxylic nonsteroidal anti-inflammatory drugs.

     

Aerobic metabolism in snapping turtles,Chelydra serpentina,after thermal acclimation

• 1.1. Oxygen consumption of resting and active snapping turtles at 10, 20 and 30°C was measured following acclimation to 10 and 25°C.
• 2.2. Cold acclimation results in depressed resting and active rates of oxygen consumption and in a decreased aerobic metabolic scope for activity; these changes facilitate hibernation.
• 3.3. Warm-acclimated animals have a high aerobic capacity which supports aquatic and terrestrial activity.

     

Respiratory gas concentrations in the microhabitats of some florida arthropods

• 1.1. The concentrations (dry gas %) of oxygen and carbon dioxide were measured in a variety of microhabitats of arthropods in Florida: at the ends of the burrows of three spider species (Sphodros abboti, Geolycosa micanopy, Cyclocosmia torreya) and a tiger beetle (Megacephala carolina) larva, within ant (Solenopsis invicta) mounds, within stumps inhabited by termites (Reticulitermes flavipes), and within and under decaying hardwood logs.
• 2.2. Hypoxia and hypercarbia occurred in all microhabitats, with the ratio of oxygen decrement to carbon dioxide increment close to one. Changes for both gases were minor in the spider burrows, under decaying logs, and within ant mounds (<2.3% for O₂ and 1.1% for CO₂) and are probably physiologically unimportant to their inhabitants.
• 3.3. In contrast, %O₂ fell to as low as 12–14%, and CO₂ rose to as high as 6–8%, in the burrows of tiger beetle larvae, within decaying logs, and inside decaying stumps inhabited by termites.
• 4.4. Such changes, particularly for CO₂ may present a challenge to organisms living in these microenvironments.
• 5.5. Approximately 20–25% of the changes in the concentrations of respiratory gases in the burrows of tiger beetle larvae are attributable to the metabolism of the larva, the remainder being due to diffusional exchanges with the soil.

     

Laboratory studies on the oxygen consumption of the marine teleost,Lichia amia (Linnaeus, 1758)

• 1.1. The oxygen consumption of the marine teleost, Lichia amia was investigated under controlled laboratory conditions.
• 2.2. The routine oxygen consumption showed a strong circadian rhythm with the fish being mainly active during the light period.
• 3.3. The specific mass exponent (dimension: μg O₂/g/hr) is temperature independent and ranges from 0.27–0.29.
• 4.4. Starving the fish results in a mean decrease in active, routine and standard oxygen consumption of 21%, 24% and 20%, respectively.
• 5.5. Feecling led to an increase in the oxygen consumption of the teleosts, with the mean metabolic rate over the 24 hr that followed, being 58% and 50% higher for fish that had been starved for 162hr and 40 hr, respectively.
• 6.6. Apparent SDA showed some variation and ranged from 6.0 to 35.5%.
• 7.7. The results obtained are generally in agreement with those recorded for other teleosts.

     

Temperature acclimatization in the filtering rates and oxygen consumption of Daphnia ambigua scourfield

• 1.1. Filtering rates and oxygen consumption were measured in the field on a wild population of the fresh-water limnetic cladoceran Daphnia ambigua.
• 2.2. Filtering rates increased with increasing body size and were significantly affected by environmental temperature.
• 3.3. Oxygen consumption increased with increasing body size; there was no significant difference among b values determined at different environmental temperatures but bs were highest at low temperatures. decreased progressively at higher temperatures and increased at the highest temperatures.
• 4.4. Temperature significantly affected the rate of oxygen consumption.
• 5.5. Both filtering rates and oxygen consumption evidenced classical translation to the left in cold-acclimatized animals. An environmental temperature near 12°C apparently separates warm- and cold-acclimatization processes.

     

The effects of acclimatization on body weight and oxygen consumption in Dipodomys panamintinus

• 1.1. Seasonal acclimatization effects on oxygen consumption, body temperature, and body weight were evaluated in three different experimental groups of Dipodomys panamintinus.
• 2.2. Body weights of wild field as well as captive animals housed in outdoor sand cages were maximum in winter and lowest in summer for both sexes.
• 3.3. Mean oxygen consumption was maximum in winter and lowest during spring in both sexes of the wild field and captive exposed groups.
• 4.4. Neither weight nor oxygen consumption of indoor control animals varied with the seasons.
• 5.5. No significant differences in body temperatures were observed during either the fall or winter seasons.

     

Variations in response to environmental hypoxia of different colour forms of the shore crab,Carcinus maenas

• 1.1. The oxygen consumption of red and green Carcinus in normoxic and hypoxic sea water was determined, using an oxygen electrode in a sealed respirometer.
• 2.2. The red crabs had significantly higher “excited” oxygen uptake rates and a lower ability to compensate for hypoxia than the green crabs.
• 3.3. Red Carcinus display an emersion response to declining oxygen at lower oxygen tensions than the green crabs.
• 4.4. Mortality of red crabs exposed to prolonged anoxia was much greater.
• 5.5. The relationship of these findings to the zonation of the two colour forms on the shore is discussed.

     

Measurements of oxygen consumption in Mytilus edulis during exposure to,and recovery from,high sublethal concentrations of formaldehyde,benzene and phenol

• 1.1. The rate of oxygen consumption has been monitored continuously in M. edulis during acute exposure to high sublethal concentrations of formaldehyde, phenol and benzene and subsequent recovery periods of 96 hr.
• 2.2. The results are discussed in relation to changes in the electrochemical potential difference of sodium, the content of ATP and the tissue concentration of strombine.
• 3.3. After exposure to benzene and phenol, an increase in the rate of oxygen consumption that could not be explained by oxygen debt from the exposure period was observed.
• 4.4. Depression of the rate of oxygen consumption after exposure to formaldehyde may be explained by a reduced ability to extract oxygen from the water.
• 5.5. The pattern of oxygen consumption and behavioural responses, as well as the combined changes in the biochemical markers, were distinctly different in the three cases.

     

The effect of low levels of carbon dioxide on metabolism of Mus musculus

• 1.1. In this study we measured the metabolic response of individual mice to low concentrations of carbon dioxide in air (0.14 to 1.7%). Both oxygen consumption (V_o2) and carbon dioxide (V_o2) were determined, and the respiratory quotient (R) was calculated.
• 2.2. V_o2 was significantly reduced at levels of 0.14 to 0.50% CO₂ in the air. At 0.23% for example, V_o2 dropped from 3.11 ± 0.6 to 1.26 ± 0.69 cc O₂/g × hr. R increased from 0.7 to 1.0 and higher throughout the 6-hr testing period, which consisted of 1.5 hr of exposure to 0.0% CO₂, 1.5 hr of exposure to a test gas and a repetition of 1.5 hr each of baseline and test exposures.
• 3.3. We conclude that low levels of CO₂ such as mice might encounter in a nest, burrow or even metabolic chamber may effect a feedback mechanism which acts to decrease metabolism.

     

Varying effects of calcium on the oxidation of palmitate and α-ketoglutarate in isolated rat liver mitochondria incubated in KCl-based and sucrose-based media

• 1.1. Isolated mitochondria from rat liver were incubated in the presence of [U-¹⁴C]palmitate, ATP, CoA, carnitine, EGTA (ethylene glycol bis (β-aminoethyl ether) N,N′-tetraacetic acid) and varying amounts of calcium.
• 2.2. When a KCl-based incubation medium was used, the oxidation of palmitate was inhibited when the concentration of free calcium was increased from about 0.1–10μM.
• 3.3. When a sucrose-based incubation medium was used, the basal rate of palmitate oxidation was about half of that observed with the KCl-medium and calcium had a stimulatory effect.
• 4.4. With the KCl-medium the rate of oxygen consumption was inhibited by calcium with α-ketoglutarate as well as palmitate as the respiratory substrate.
• 5.5. No inhibitory effect of calcium was observed with succinate or β-hydroxybutyrate.
• 6.6. With the KCl-medium and with α-ketoglutarate as the respiratory substrate, state 3 respiration but not state 4 respiration was inhibited by calcium.
• 7.7. When the sucrose-medium was used, state 3 respiration was first inhibited by calcium, but this inhibition was gradually relieved and the respiratory rate finally became higher than it was before calcium addition.

     

The influence of aerial exposure on gas exchange and cardiac activity in the shore crab,Carcinus maenas (L.)

• 1.1. The cardiovascular physiology of adult Carcinus maenas (L.) emerging into air has been investigated at three different air temperatures.
• 2.2. Transition from seawater to air or vice versa triggered transient increases in cardiac and locomotor activity.
• 3.3. However, crabs became inactive 5–10 min after emerging from seawater (15°C) into air at the same temperature (15°C) or at lower temperatures (12–13°C) and heart rate fell.
• 4.4. At higher air temperatures (18–20°C) heart rate rose but to a lesser extent than predicted from aquatic Q₁₀ heart-rate values.
• 5.5. Crabs were again quiescent in aerial conditions.
• 6.6. Mean arterial oxygen tension (Pa_o2) was ~ 74 mmHg in submerged crabs but fell to ~ 38 mmHg in air while mean arterial carbon dioxide tension (Pa_o2) increased from 1 to 4 mmHg resulting in respiratory acidosis.
• 7.7. A model of gill function is proposed to explain the development of internal hypoxia in air.
• 8.8. The results are discussed in relation to the distribution of adult and juvenile C. maenas in situ.

     

The effect of salinity on respiratory metabolism in selected ontogenetic stages of the freshwater shrimp Macrobrachium olfersii (Decapoda,palaemonidae)

• 1.1. The effect of acute salinity exposure (0, 7, 14, 21, 28 and 35%.S) on the respiratory metabolism of selected ontogenetic stages (zoeae, postlarvae and adults) of the freshwater shrimp Macrobrachium olfersiiwas examined.
• 2.2. Metabolic rates are salinity independent from 14 to 28%. S in zoeae 1–4, but tend to increase with increasing salinity in zoeae 5 and 8. Postlarvae exhibit maximal rates in midrange salinities while in adult shrimps, oxygen consumption rates decrease with salinity increase.
• 3.3. Salinity has little effect on the metabolism-weight relationship, regression analysis indicating that b varies from 0.69 in 0%. S to 0.62 in 35%. S.
• 4.4. Data are discussed as to whether larval responses reflect adaptation to the adult biotope and whether development of the larval neurosecretory system might affect metabolic response to salinity exposure.