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.

     

Cardiac frequency compensation responses of adult blue crabs (Callinectes sapidus Rathbun) exposed to moderate temperature increases

• 1.1. Cardiac frequency patterns of Callincctes sapidus Rathbun were used to evaluate potential thermal stress after exposure to 5°C increases over a range of acclimation temperatures from 5° to 30°C.
• 2.2. An acclimated rate-temperature curve (R-T curve), acute R-T curves of the stabilized rates at the increased temperatures and Q₁₀ temperature coefficients were used to assess the significance of the changes in rate frequency.
• 3.3. The acclimated R-T curve showed that blue crabs go through a series of seasonal adaptation types characterized by a plateau of perfect adaptation for both cold and warm adapted organisms. Paradoxical adaptation occurred between the transition from cold to warm acclimation temperatures.
• 4.4. The acute R-T curves showed that cardiac frequency was highly responsive to a 5°C increase when the organisms were acclimated to low temperatures.
• 5.5. The Q₁₀'s of the acute R-T curves at the warm acclimation temperatures approximated those values derived for the acclimated R-T curve.
• 6.6. This suggests that the temperature increase had a negligible effect on the warm adapted crabs, that is, little or no thermal stress occurred.

     

The dependence of oxygen consumption of the common whelk (Buccinum undatum) on hypoxia,salinity and air exposure

• 1.1. Oxygen consumption of low salinity (20‰) acclimated whelks decreases markedly upon acute exposure to hypoxia (P_WO₂ = 35 Torr), but almost regenerates its original level within 48 hr exposure to the hypoxic condition.
• 2.2. This ability to regain the original level of oxygen consumption is not seen in high salinity (35‰) acclimated whelks.
• 3.3. Oxygen consumption in air at 10°C is more than twice the rate shown by low salinity acclimated whelks in normoxic water (P_WO₂ = 150 Torr).
• 4.4. Q₁₀ for oxygen consumption in air is about 1.0 in the temperature range 10–20°C.

     

Oxygen consumption of the sandy-beach whelk Bullia digitalis meuschen at different levels of activity

• 1.1. O₂ consumption of suspended Bullia digitalis is not related to water current speed or degree of turbulence, where these are kept constant.
• 2.2. The highest levels of O₂ uptake at 15°C are obtained by producing fluctuating surges of turbulence, the animals responding to changes in the movement of water.
• 3.3. In buried animals O₂ consumption decreases with time in the absence of water movements.
• 4.4. Burrowing and surface crawling require less energy than transport in the surf.

     

Effect of size and temperature on the oxygen consumption of the brown shrimp Penaeus californiensis (Holmes, 1900)

• 1.1. The routine rate of oxygen consumption by Peneaus californiensis was determined for the size groups with average weights of 0.26, 2.31 and 10.01 g at five temperatures (19, 23, 27, 31 and 35°C).
• 2.2. Oxygen consumption (mg O₂/g min) was independent of dissolved oxygen (DO) level down to 1.8mg/l, increased with temperature (P < 0.05) from 0.0015mg O₂/g min for the preadults at 19°C to 0.0106 mg O₂/g min at 35°C for the postlarvae, and was inversely proportional to weight (P < 0.05).
• 3.3. The thermal coefficient (Q₁₀) indicated a higher sensitivity by preadults to temperature variations.

     

Electrophysiological and metabolic responses of the isolated teleost retina to changes in po2, and temperature

• 1.1. Comparisons of electrophysiological responses (ERG) were made between two different in vitro preparations of teleost retina.
• 2.2. The ERG was independent of temperature over the normal environmental range.
• 3.3. The Q₁₀ demonstrated temperature independence between 5 and 20°C.
• 4.4. The electrical response of the isolated retina was found to be independent of partial pressures of oxygen at levels above 250 mm Hg.

     

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 temperature on the swimming of a teleost (Clupea harengus) and an ascidian larva (Dendrodoa grossularia)

• 1.1. Using a high-speed video system operating at 400 frames/sec, the effects of temperature on tail beat frequency, swimming speed and stride length were examined in newly hatched larvae of herring (Clupea harengus L.) and in tadpole larvae of the ascidian Dendrodoa grossularia van Beneden.
• 2.2. The effect of temperature was linear; the tail beat frequency of 8 mm-long herring larvae increased from 19 Hz at 5.6°C to 37 Hz at 14.9°C (Q₁₀ = 2.04); that of 2 mm-long Dendrodoa larvae increased from 10 Hz at 9.6°C to 23 Hz at 18.1°C (Q₁₀ = 2.52).
• 3.3. Burst swimming speeds of herring larvae increased from 80 mm/sec at 5°C to 150 mm/sec at 15°C, stride length remaining constant at about 0.5 of the body length for each tail beat.
• 4.4. More continuous swimming of Dendrodoa increased from 4.0 mm/sec at 10°C to 11.5 mm/sec at 18°C, the stride length increasing from about 0.15 to 0.25.

     

Oxygen consumption in the tortoise,Testudo hermanni G., subjected to sudden temperature changes in summer and autumn

• 1.1. A respirometer for long-term measurements of oxygen consumption in terrestrial vertebrates is described.
• 2.2. The tortoise, Testudo hermanni Gmelin, investigated in summer and autumn, presents a day-night rhythm of oxygen consumption at 28 and 18°C but not at 8°C.
• 3.3. The standard metabolic rate presents an important and constant thermal dependence in the range 8-18-28°C.

     

Seasonal variation in the metabolic rates and Q10-values of the fingernail clam,Sphaerium striatinum lamarck

• 1.1. Metabolic rates were highest during periods of maximum reproduction.
• 2.2. The exponent of the metabolic rate-weight equation varied seasonally, rates of metabolism of small animals exhibited greater annual fluctuations than those of large animals.
• 3.3. Absolute and weight-specific Q₁₀s (determined at 5–10°C above field temperatures) for smaller clams were greatest in the winter; absolute values of Q₁₀ were highest for larger individuals in the summer.
• 4.4. Small clams had Q₁₀ < 1.0 in the summer; Q₁₀-values for larger clams were near 1.0 at this time.
• 5.5. 38.9% of the total energy assimilated by the population annually was allocated to metabolism, which is near the low end of the range of values reported for freshwater molluscs, suggesting that this species can partition a large amount of energy to growth and reproduction.

     

Metabolic and behavioral responses of American kestrels to food deprivation

• 1.1. The effect of short-term (79 hr) food deprivation at 27°C on body mass, locomotor activity, body temperature (T_b), and resting oxygen consumption was determined in eleven American kestrels (Falco sparverius).
• 2.2. The change in body mass during resting followed the relation, % mass remaining = 99 e^{0.07(days fasting)}. There was no significant difference in the rate of relative mass loss between males and females.
• 3.3. Locomotor activity, measured as perch hopping, was highly variable in both control and fasted birds and showed no correlation with stage of the fast, basal metabolic rate (BMR), or rate of mass loss during food deprivation.
• 4.4. Body temperatures of fasted birds declined continuously by 0.2–0.4°C per day from 39.3 to 38.3°C.
• 5.5. Both males and females responded to food deprivation with a decrease in metabolism. By the third night of fasting, BMR had declined 23.4% from 0.845 W (bird day)⁻¹ to 0.647 W (bird day)⁻¹. The observed reduction in BMR is 2.4 times that expected from a 1°C decline in T_b (assuming Q₁₀ = 2.5) indicating active suppression of metabolism.

     

Oxygen consumption and haemocyanin function in the freshwater snail Marisa cornuarietis (L.)

• 1.1. The MO₂ for branchial respiration in adult snails increased from 0.24 mmol/l/O₂ kg/hr at 18°C to 0.83 mmol/l/O₂ kg/hr at 40°C. Q₁₀ values were 2.75 between 35 and 40°C and 1.8 between 18 and 30°C.
• 2.2. The haemocyanin (31.9 ± 5.8 mg/ml) has a high oxygen affinity (6.28 ± 0.8 at 25°C) with a reversed Bohr effect measured between a pH of 6.80 and 7.95 with gelchromatographed haemolymph, and measured between a pH of 7.34 and 8.10 for native haemolymph.
• 3.3. Growth rate is optimal between 27 and 30°C whilst at 24°C stunted growth was found.
• 4.4. At 25°C the same MO₂ values were found for aerial and aquatic respiration.

     

Thermoregulation and oxygen consumption in Kirk's dik-dik (Madoqua kirkii) at ambient temperatures of 10–45°C

• 1.1. Thermoregulatory and metabolic responses of dik-dik (Madoqua kirkii) were measured over an ambient temperature (T_a) range of 10–45°C.
• 2.2. The lower critical temperature was estimated at T_a 25°C.
• 3.3. At T_a 40 and 45°C, dik-dik panted and oxygen consumption fell below that measured at thermoneutrality.
• 4.4. The dik-dik appears well adapted to a high T_a but can cope with a low T_a only at a high metabolic cost.

     

An experimental analysis of the metabolic rate and food utilization of northern pike

• 1.1. The metabolism of northern pike (Esox lucius) was determined by oxygen consumption and ration experiments to obtain data for an energy budget analysis.
• 2.2. Metabolic measures of oxygen consumption were most reliable, and were described by the equations: R_met = 27.5 Wt^0.82 at 14°C and R_met = 1.6 Wt^0.97at 2°C.
• 3.3. In addition, conversion efficiency (K₂ = 0.319 ± 0.064) and assimilation efficiency (0.872 ± 0.060) were determined.
• 4.4. Proximate composition of fish under various feeding regimes indicated that energy gain or depletion from the body was due to changes in amount of whole body tissue or body protein, rather than specific utilization or storage of lipid.

     

The effects of temperature and eyestalk extracts on oxygen consumption of the crayfish Cambarus acuminatus (Faxon)

• 1.1. The pattern of VO₂ of 4 and 25°C acclimated Cambarus acuminatus was one of normal compensation with cold acclimation resulting in translation and clockwise rotation of the rate-temperature (R-T) curves.
• 2.2. Acclimation patterns were significantly influenced by the sequence in which crayfish experienced experimental temperatures.
• 3.3. Eyestalk extracts prepared from warm acclimated crayfish significantly decreased VO₂ in eyestalkless cold acclimated recipients.

     

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.

     

Effect of temperature on oxygen consumption and heart rate of the australian crayfish Cherax tenuimanus (Smith)

• 1.1. Oxygen consumption at 18°C was 60% of the rate at 22 and 26°C.
• 2.2. Critical points, where the rate of oxygen consumption changed, were defined at 22°C (2.89 mg DO) and 26°C (3.46 mg DO). Linear regressions were fitted showing that oxygen consumption declined significantly (81.5% ±4.5) below the critical point.
• 3.3. Oxygen consumption was proportional to weight. Allometric relationships resulted in variable temperature-related coefficients for respiratory dependence on weight, a reflection of the crayfish adaptation towards re-establishment of a new equilibrium state.
• 4.4. Heart beat rate was lower at 18°C, and highest at the acclimation temperature (22°C). Stress at 26°C was evident.

     

The effects of temperature and moisture on survival capacity,cuticular permeability,hemolymph osmoregulation and metabolism in the scorpion,Centruroides hentzi (banks) (scorpiones,buthidae)

• 1.1. The temperature and water relations of Centruroides hentzi females were investigated. At 12 and 72% relative humidity (RH), the lower and upper Lt₅₀ were -4.5 and 43.7°C, and -4.7 and 45.1°C, respectively. When exposed to high temperature stress, survivorship was significantly greater under mesic conditions.
• 2.2. Cuticular water loss was higher under xeric conditions (12% RH), ranging from 0.061 mg/cm²/hr at 30°C to 0.211 at 41°C.
• 3.3. Exposure to dry air (0–5% RH) resulted in a significant increase in hemolymph osmolality: from 441 to 688 mOsm over a 5 day period.
• 4.4. Mean oxygen consumption rates increased from 161.7 mm³/g/hr at 34°C to 541.6 at 44°C. ATPase activity was significantly higher in animals acclimated and tested at 35°C.

     

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.

     

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.