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).

     

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 time on physiological changes in eel Anguilla anguilla,induced by lindane

• 1.1. Eel were exposed to a sublethal concentration of lindane (0.335 ppm) for 6, 12, 24, 48, 72 and 96 hr.
• 2.2. Concentrations of glycogen, glucose, lactate, pyruvate and lipids were determined in gill tissue after lindane exposure.
• 3.3. Gill glycogen descreased and glucose levels increased at 6 hr of treatment, lactate and pyruvate concentration increased between 6 and 48 hr. Total lipid values decreased between 6 and 24 hr; thereafter, the levels increased up to 72 hr of exposure.
• 4.4. Clear changes were found in all parameters tested in gill tissues. The observed effects of lindane on metabolism in fish are discussed in relation to acute stress syndrome.

     

Root effect hemoglobins in marine fish

• 1.1. The Root effect was evaluated in hemolysates from 26 species of bony fish and 20 species of cartilaginous fish found on the Brazilian southeastern coast.
• 2.2. Teleost Root shifts, with a single exception, are correlated with the presence of the choroid rete mirabile but not with its counterpart in the swimbladder.
• 3.3. Five ray species displayed weak and moderate Root effects despite the absence of choroid and swimbladder rete.
• 4.4. The presence and intensity of the Root effect is probably primarily related to the high oxygen demand of the retina and with the importance of visual perception in fish.
• 5.5. In marine teleosts the magnitude of the Root effect seems to be associated with the presence and size of both the choroid rete and the pseudobranch.
• 6.6. An antioxidant protection of the fish eyes can be advocated for the pseudobranch.

     

The peculiarities of nitrogen excretion in sturgeons (Acipenser ruthenus) (Pisces,Acipenseridae)—I. the influence of ration size

• 1.1. The nonfaecal nitrogenous excretion rate in starved sterlet fingerlings and fingerlings fed on different rations was investigated. The weight of the fish and temperature of the water was 43 g and 17.5°C, respectively.
• 2.2. In the nonfaecal excrements of starved sterlets the ammonia: urea ratio was substantially lower than in teleosts. This ratio was found to be 1.4:1.
• 3.3. In fed sterlets the urea excretion rate was higher than in starved ones but independent of ration size.
• 4.4. During the day the urea excretion rate in sterlets was constant.
• 5.5. The ammonia excretion rate accelerated 2 hr after feeding and reached its peak duration 6–11 hr after depending on the ration size.
• 6.6. Total ammonia output in the sterlet increased following the increase of ration size up to 8.4% of body wt. Further increases in ration size did not cause the corresponding elevation of ammonia excretion rate.

     

Oxygen consumption in the fathead minnow (Pimephales promelas rafinesque)-I: Effects of weight,temperature, group size,oxygen level and opercular movement rate as a function of temperature1

• 1.1. A relationship is evident between oxygen consumption (OC in cm³/hr) and weight (WT in g) such that: OC = −0.580 (WT)^1.053
• 2.2. Fathead minnows failed to exhibit immediate rate compensation as a result of acute temperature changes. Minnows showed an exponential increase in weight-specific oxygen consumption with temperature (in °C), resulting in a Q₁₀ of over three. The equation is: OC = 10^0.0482 (Temp.) − 1.268.
• 3.3. Minnows acclimated to water temperatures of 5–21°C showed a steady increase in opercular movement rates (OMR) (ventilation rates) as expressed by the equation: OMR = 0.1968 (Temp.)² + 1.064.
• 4.4. Grouping more than two fish per chamber resulted in an increase in oxygen consumption. The relationship of group size (GS) to oxygen consumption is: OC = 0.04059 (GS)² − 0.2017 (GS) + 0.5353.
• 5.5. Oxygen consumption is a function of dissolved oxygen level. This relationship is shown by the equation: OC = 0.003049 (OL)³ − 0.06359 (OL)² + 0.4211 (OL) − 0.4020 where OL is oxygen level. Due to high variability, it is statistically impossible to determine oxygen level ranges in which they conformed and those in which they regulated.

     

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.

     

Renal function in migrating adult atlantic salmon,Salmo salar L.

• 1.1. Renal function in migrating adult Atlantic salmon was studied in sea-water (SW) and following abrupt transfer to fresh water (FW).
• 2.2. Urine flow rate of SW-adapted fish, 0.72 ml/kg/hr, increased 6.3-fold to 4.55 ml/kg/hr after 2–3 days in FW, later decreasing to around 1 ml/kg/hr.
• 3.3. Changes in glomerular filtration rate and ion filtration rates largely paralleled changes in urine flow. In SW-adapted salmon about 4% of excreted magnesium is filtered. Tubular magnesium secretion declined within 1 day of FW transfer.
• 4.4. During the period of maximum diuresis, urinary sodium loss is 77% of the branchial sodium uptake rate. This falls to less than 20% in FW-adapted fish.

     

Specific dynamic action and feeding metabolism in common carp,Cyprinus carpio L.

• 1.1. Oxygen uptake attributable to Specific Dynamic Action (SDA) was measured in common carp, Cyprinus carpio L. (63.6–84.0 g) fed on 20, 35 and 50% dietary protein at 0.40 to 1.00% ration levels at 28°C.
• 2.2. After feeding both SDA magnitude and mean peak oxygen consumption increased directly with dietary protein and ration levels. SDA duration was not significantly related to dietary protein but significantly increased with ration levels.
• 3.3. SDA coefficients were 8.99, 13.51 and 15.94% with 20, 35 and 50% dietary protein showing a direction relationship to the protein content. The SDA coefficient did not change with ration size.
• 4.4. SDA models resulting from this work are of great interest for the aquaculturist, as post-feeding oxygen requirements in an intensive fish culture can be predicted where dietary protein and ration levels are known.

     

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.

     

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.

     

Effects of dehydration and rehydration on the intravascular space in horses

• 1.1. The resistance of sub-tropical horses, and desert-dwelling horses to 72 hr dehydration/24 hr rehydration was investigated via changes in red cell parameters and plasma protein concentration.
• 2.2. Red cell count, haemoglobin and haematocrit increased up to 48 hr dehydration. Between 48 and 72 hr dehydration these parameters decreased, implying a fluid shift onto the intravascular space from the interstitium/hindgut. Most parameters had regained baseline values by 24 hr rehydration.
• 3.3. Mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration and total plasma protein were not significantly different between breeds at, or between most stages of hydration.
• 4.4. Protection of plasma volume during dehydration/rehydration was aided by maintaining intravascular protein (especially albumin) levels. Red cells were transiently dehydrated and overhydrated but resisted osmolysis.

     

Effects of salinity and temperature on oxygen consumption in a freshwater population of Palaemonetes antennarius (Crustacea,decapoda)

• 1.1. After step-like increases in salinity the shrimps exhibit the smallest increase in oxygen consumption in the lower salinity range. At higher salinities the shrimps show longer recovery times and greater increases in the metabolic rate after salinity shock.
• 2.2. In steady-state experiments, the shrimps display the lowest oxygen consumption rates near the isosmotic point. The lowest metabolic rates occur at salinities of 3‰ and 10‰ At salinities of 20‰ and above the rate of metabolism increases by 20–30%.
• 3.3. The calculated osmoregulatory work for animals in fresh water amounts to only 2.7% of routine metabolism and drops to 1.1% for shrimps in 3‰ and 0.7% in 5‰ salinity.
• 4.4. Locomotory activity in the form of position change was not responsible for the increased oxygen consumption of the animals after salinity shocks. A “tentative swimming activity” by fast and frequent beating of the pleopods without position change may be an important factor in the increase of metabolic rates.
• 5.5. In its temperature response, the brackish water population has a higher metabolic rate than the freshwater one. Between 5 and 35°C Q ₁₀-values range from 4.01 to 1.37.

     

Changes in blood metabolite concentrations in response to repeated capture,anaesthesia and blood sampling in the golden perch,Macquaria ambigua

• 1.1. The major metabolic changes associated with repeated capture, aquarium transfer, anaesthesia and blood sampling were investigated in an Australian freshwater fish, the golden perch (Macquaria ambigua),
• 2.2. A compounded stress response was seen after repetition of the procedure, in which the plasma glucose rose within 3 hr and amino acid concentrations rose and the serum free fatty acids concentration fell after 24 hr.
• 3.3. Alanine was identified as an important circulating energy store in the stress response of golden perch.
• 4.4. No change was noted in the serum protein, plasma lactate or β-hydroxybutyrate concentrations, indicating that tissue damage and hypoxia were absent, and that degradation of free fatty acids did not produce metabolites excess to the requirements of gluconeogenesis and the tricarboxylic acid cycle.

     

An investigation of gluconeogenesis in marine teleosts,and the effect of long-term exercise on hepatic gluconeogenesis

• 1.1. Gluconeogenesis from ¹⁴C-substrates was measured in liver slices from marine teleosts.
• 2.2. 0.56 to 2.78 μmols of lactate were incorporated/g wet wt/hr with the higher rates corresponding to the active species.
• 3.3. Snapper (Chrysophrys auratus) and bream (Acanthopagrus butcheri) exercised continuously for 14 days showed a substantial increase in the incorporation of lactate; snapper confined for 4 months showed a significant decrease in the incorporation of lactate, compared to freshly caught individuals.
• 4.4. Pyruvate carboxylase and fructose 1,6-diphosphatase were found in red muscle. Some phosphoenolpyruvate carboxykinase may also be present. The three enzymes were present in liver. Possible roles for the enzymes in teleost muscle are discussed.

     

Protein digestion and ion concentrations in rainbow trout (Salmo gairdnerii Rich.) digestive tract in sea- and fresh water

• 1.1. Rainbow trout maintained in fresh water or Actapted to sea-water for 24 hr were fed casein-based dry diet. After feeding, fish were kept in fresh water (FW) or transferred to artificial sea-water (SW) and sacrificed after 10 or 20 hr.
• 2.2. The digestive tract was separated into five parts: stomach, pyloric caeca region, middle intestine and two equal lengths of rectum.
• 3.3. The content of these parts was analysed for ions Na⁺, K⁺, Cl⁻, Mg²⁺ and for free, peptide and total amino acids.
• 4.4. In the fish stomach all ions, with the exception of Ca²⁺, indicate drinking of sea-water. In the pyloric caeca region Na⁺ appears to be efficiently absorbed in SW fish but influxed in FW fish. In the rectum of SW fish K⁺ appears to be reabsorbed but Na⁺ concentrated in faeces.
• 5.5. Free amino acid concentrations were always higher in gut lumen of SW than in FW fish in respect to time after feeding and portion of intestinal content. Free amino acids constitute at most 7.4–8.7% of total amino acids in the content of pyloric caeca region.
• 6.6. Peptide amino acids, being mostly di-, tri- and tetra-peptides, increased in stomach content from 14.7 to 28.4% of the total, from 6 to 10 hr after a meal in SW fish. Peptide amino acids constituted 80.3–89.0% of total amino acids in intestinal content of the pyloric caeca region. These peptide portions decreased in the mid-intestine (47.5–52.5%) and increased again in the rectum (73.6–76.0%).
• 7.7. It was concluded that in rainbow trout fed in both sea- or fresh water, ion concentrations do not seem to interfere with protein digestion and nutrient absorption in alimentary tract.

     

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.

     

Effect of temperature and salinity on the oxygen consumption of laboratory produced Penaeus californiensis postlarvae

• 1.1. The oxygen consumption by P. californiensis postlarvae (mean wt = 0.38 g) was determined at five different temperatures and four salinities.
• 2.2. The O₂ in each chamber was recorded at 10 min intervals for 1 hr. The time course of oxygen depletion was independent of O₂ concentration down to 1.6 mg/l.
• 3.3. Oxygen consumption increased with temperature from 0.0045 mg/g/min at 19°C, to 0.0142 mg/g/min at 35°C. The thermal coefficient (Q₁₀) indicated a very high sensitivity of the postlarvae to temperature variations at 19–23°C.
• 4.4. The results show that oxygen consumption significantly depends on temperature (P < 0.001) while salinity has only a marginal effect.

     

Acute toxicity and bioaccumulation of endosulfan in rotifer (Brachionus calyciflorus)

• 1.1. The acute toxicity of endosulfan was determined for the freshwater rotifer Brachionus calyciflorus.
• 2.2. The mean 24 hr lc₅₀ value for endosulfan was 5.15 ppm with a coefficient of variation of 14.7%.
• 3.3. Rotifers were exposed at two sublethal concentrations (1.5–2.0 ppm) of endosulfan for bioaccumulation experiments, for an exposure time of 24, 48, 72 and 96 hr. The rotifers were fed with Nannochloris oculata (5 × 10⁵cell/ml).
• 4.4. The highest accumulation of endosulfan was found 24 hr after the start of the exposure to 1.5 ppm of the toxicant. A steady-state concentration in rotifer was reached between 24–48 hr, followed by a gradual decrease until 96 hr.

     

Arginase activity in different fish species and tissues

• 1.1. Arginase activity was measured in different tissues from eight species of fish.
• 2.2. Spur dogfish showed a very high arginase activity compared with the other species analysed.
• 3.3. The activity in teleosts was mainly found in tissues of high metabolic activity (liver, kidney and red muscle).