Increasing Acclimation Temperature Research Articles

Organ patterns and natural fluctuations of blood enzymes of rainbow trout ( Salmo Gairdneri rich.)

1. 1. Activities of up to 12 enzymes in six organs and their natural fluctuation in the blood serum of rainbow trout have been determined. 2. 2. Characteristic patterns of enzyme activities were found in white muscle, heart, liver and kidney. 3. 3. Starvation only influenced the serum activity of alkaline phosphatase (AP). 4. 4. Increasing acclimation temperature led to an increase of the serum activity of lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), glutamate pyruvate transaminase (GPT), leucine arylamidase (LAP) and to a decrease of AP. 5. 5. The serum activity of LDH, HBDH, glutamate oxalacetate transaminase (GOT) and creatine phosphokinase (CPK) showed distinct seasonal fluctuations with a minimum in summer. 6. 6. Serum activities of GOT, GPT and CPK were higher in mature males than in mature females or juveniles.

Response of the mixed-function oxidase system to toxicant dose, food and acclimation temperature in the bluegill sunfish

The degree of induction of hepatic mixed function oxidase (MFO) enzymes in fish is modulated by environmental conditions. This study was designed to investigate the influence of water temperature, presence or absence of food, and exposure to benzo(a]pyrene (BaP) on the inductive response of bluegill sunfish ( Lepomis macrochirus). The results show an increase in 7-ethoxyresorufin O-deethylase (EROD) activity with an increase in acclimation temperature and dose. This activity appears to be associated with a very small fraction of the total cytochrome P-450 induced. Major changes were observed in the 53- and 57-kilodaltons (kDa) electrophoretic bands.

Temperature‐dependence of cardiac output and regional blood flow in rainbow trout, Salmo gairdneri Richardson

Cardiac output, blood flow distribution and regional perfusion were determined in free‐swimming rainbow trout acclimated to 6, 12 and 18°C, using the indicator dilution and microsphere methods. Cardiac output (ml min−1 kg−1) increased linearly with increasing temperature, while circulation time decreased. Blood flow distribution (% of cardiac output) to the spleen, liver, kidney, gall bladder and gastro‐intestinal tract was significantly reduced at 18°C relative to 6°C‐acclimated fish. White muscle received the largest fraction of cardiac output, and blood flow distribution to white muscle increased significantly with increasing acclimation temperature. Blood perfusion (ml h−1 g−1) of various organs and red muscle was not influenced by acclimation temperature, while white muscle perfusion increased with increasing temperature. These results demonstrate physiological adaptation of the cardiovascular system of rainbow trout to changes in acclimation temperature.

Critical and Chronic Thermal Maxima of Northern and Florida Largemouth Bass and Their Reciprocal F1and F2Hybrids

Abstract Thermal responses varied among four genetic stocks of juvenile largemouth bass: northern largemouth bass Micropterus salmoides salmoides (NLMB), Florida largemouth bass M. s. floridanus (FLMB), and both reciprocal F1 hybrids, NLMB ♀ x FLMB ♂ (N x F) and FLMB ♀ x NLMB ♂ (F x N). Thermal responses for each stock were measured as the critical thermal maximum, the temperature at which death occurred during a temperature increase of 0.2°C/min, for fish at various acclimation temperatures (8, 16, 24, 32°C); and chronic thermal maximum, the temperature at which death occurred during a temperature increase of 1°C/d, for fish acclimated to 32°C. The rank order of values for both response measurements was identical for the four stocks: F x N > FLMB > N x F > NLMB. Increased acclimation temperature resulted in significant, proportional increases in the critical thermal maxima for all stocks. In addition, second-generation hybrid stocks (N x F F2 and F x N F2) that were acclimated at 24°C produced similar cr...

THE EFFECTS OF TEMPERATURE AND WATER AVAILABILITY ON ION AND ACID-BASE BALANCE IN HEMOLYMPH OF THE LAND HERMIT CRABCOENOBITA CLYPEATUS

Temperature acclimation (18-30°C) and dehydration (to 86% of initial mass) are two problems frequently encountered by the land hermit crab, Coenobita clypeatus. Their individual and combined effects on hemolymph ion and acid-base status were assessed. With free access to 10% SW, crabs maintained a constant degree of hydration, with hemolymph marginally hypo-osmotic to full strength SW. Increased acclimation temperature produced a reduction in pH, characteristic of ectotherms and consistent with maintenance of relative alkalinity which was accomplished by an elevation of CO2 tension (P,CO2). Hyperactivity resulted in some spillage of shell water and affected Cl- balance. Under water deprivation, evaporative loss declined approximately exponentially and was negatively correlated with body mass. Hemolymph osmolality and electrolyte levels were significantly increased, ionic imbalance contributing largely to the hemolymph acidosis. Hemoconcentration was less marked when combined with temperature acclimation. ...

The effect of acclimation temperature on the interactions of chlorine, ΔT and exposure duration to eggs, prolarvae and larvae of striped bass, Morone saxatilis

The effect of five acclimation temperatures on the interactions of total residual chlorine (TRC) (0.00, 0.15 and 0.30 mg l −1, ΔT (2, 6, 10°C above acclimation temperature) and exposure duration (0.08, 2.0, 4.0 h) conditions were evaluated for striped bass, Morone saxatilis, eggs, prolarvae and larvae. The range of acclimation temperatures (12.5, 15.0, 17.5, 20.0, 22.5°C for eggs and prolarvae; 15.0, 17.5, 20.0, 22.5 and 25.0°C for larvae) tested with each life stage included the lower, optimum and upper environmental temperatures that exist when these life stages may be subjected to power plant chlorination conditions. All organisms were tested using a fractional composite design in a 3 × 3 × 3 factorial matrix. Mortality of the eggs was highest at temperatures below 17.5°C; overall mortality decreased with increasing acclimation temperature. The factor causing the greatest effect with this developmental stage was ΔT, followed by TRC and exposure time. Mortality of striped bass prolarvae increased with acclimation temperature after exposure to interacting treatment factors. Interactions involving TRC were most important from 12.5 to 17.5°C; ΔT interactions were prominent at acclimation temperatures of 20.0 and 22.5°C. Larvae mortality was highest at 20°C with a gradual decrease at 25.0°C. Interactions involving ΔT, TRC and exposure time all contributed to the mortality of this life stage; TRC and ΔT caused the main effects. Striped bass eggs were the most resistant life stage; mean mortality averaged over all acclimation temperatures was approximately the same for prolarvae and larvae.

Environmental resistance and the ecology of coexisting hermit crabs: Thermal tolerance

Tolerance to increased water temperatures was determined for four, coexisting species of intertidal hermit crabs, Pagurus samuelis (Stimpson), P. hirsutiusculus venturensis (Coffin), P. granosimanus (Stimpson), and P. hemphilli (Benedict), of central California. All species showed significantly different median survival temperatures after acclimation to both 12 and 20°C. The tolerances corresponded with the intertidal zonation of the species. There was a significant increase in tolerance with an increased acclimation temperature in all species. Size had no effect on the tolerance of P. samuelis. The results support the hypothesis that differential genetic capacities of tolerance are important in influencing distributions. These findings and behavioral observations indicate that thermal conditions comparable with those created by the effluent of electricity generating facilities can cause considerable mortality to hermit crab populations on a local level.

The Effects of Temperature and Salinity Acclimation on Metabolic Rate and Osmoregulation in the Pupfish Cyprinodon salinus

Alterations in standard metabolic rate (V02), plasma osmolality and critical thermal maxima were examined in pupfish, Cyprinodon salinus, acclimated to freshwater and to Salt Creek water adjusted to salinities of approximately onehalf sea water (?2 SW; 560 mosm/kg) and sea water (SW; 1,168 mosm/kg). Three acclimation temperatures, 15, 25 and 30 C were maintained at each salinity. The V02 Of 1/2 SW and SW fish was significantly greater than that of FW fish at each acclimation temperature. V02, measured at the acclimation temperature, increased in FW and ? SW fish as acclimation temperature increased. The V02 of SW fish, however, was not significantly different between the 25 and 30 C acclimation groups. Thus, SW fish appear to fully compensate for the effects of increased temperature between 25 and 30 C. Plasma osmolality increased significantly with acclimation to increased salinity. As the acclimation temperature was increased from 25 to 30 C the plasma osmolality of the SW fish dropped significantly, and that of the FW fish rose significantly. Plasma osmolality of the ? SW fish was statistically identical at each acclimation temperature. The ability to osmoregulate in hypersaline environments then requires the elevated temperatures associated with this condition. This is consistent with natural history observations on C. salinus which only encounters high salinities during summer months when high temperatures occur. The critical thermal maximum (CTM) was significantly elevated by increasing acclimation temperature at each salinity. The /2 SW acclimated fish had higher CTM values than FW acclimated fish at each acclimation temperature, however, CTM was not further elevated by acclimation to salinities higher than ? SW.

Lethal temperature of marine fishes of the Gulf of Thailand

Twenty four marine fish species of the Gulf of Thailand were studied. The results suggested that increased acclimation temperature resulted in increased mean avoidance temperature (AT), critical thermal maximum (CTM) and upper incipient lethal temperature (UILT). At the acclimation temperature, which is normally the ambient seawater temperature of the Gulf of Thailand (28° C), the upper incipient lethal temperature ranged from 34° C to 37–5° C. Monocanthus chinensis and Cynoglosus puncticeps had the lowest thermal resistance. Mugil dussumerii, Therapon theraps and Scatophagus argus the highest and the rest in the middle range.

Effects of rapid changes in temperature on two estuarine crustaceans

Weight specific oxygen consumption (Q O 2 ) patterns of the amphipod, Gammarus sp. (acclimated to 5°, 15° and 25°C) and of juvenile blue crabs, Callinectes sapidus (15° and 25°C) were used to evaluate the potential effect of exposure to rapid temperature changes simulating once-through power plant pumped entrainment. Amphipods at all acclimation temperatures and blue crabs at 15°C responded to the temperature changes by increasing Q O 2 above pre-exposure levels after the thermal increase and then returning to pre-exposure levels. The response was judged to be a normal physiological compensation response, not a thermal stress response, as suggested by some investigators. Significant differences were found among seasonal Q O 2 , patterns in both species; Q O 2 , increased with increasing acclimation temperature. However, no seasonal stress effects were found as a result of exposure to the temperature changes. This implies that the effects of ΔT's up to 10°C from power plants of this design should have no significant impact on these organisms.

Thermal Tolerance of the Isopod Lirceus brachyurus (Crustacea:Isopoda)

The thermal tolerance of the aquatic isopod Lirceus brachyurus (Harger) was investigated. Survival, as measured by the time to 50% mortality (LT50), in- creased with increasing acclimation temperature. A tolerance polygon was constructed which defined the range of temperatures (0-23 C) tolerated by the isopods for 2 weeks. Upper lethal temperatures were lower than recorded for other isopod species. Lower lethal temperatures were related to those of other isopod species and to ice mineralization of creek water. The thermal tolerance of L. brachyurus did correspond to maximum and minimum water temperatures recorded in the study creek. The ecological significance with respect to the biology and habitat of L. brachyurus, and to power plant operation, is discussed.

Changes in the Fatty Acyl Composition of Phospholipids in the Optic Tectum and Optic Nerve of Temperature-Acclimated Goldfish

The optic tectum and optic nerves of goldfish that were acclimated to 5, 15, and 25 C were examined for their phospholipid composition, and the acyl group composition of the various phospholipid species was determined. The acyl group composition of 1,2-diacyl-sn-glycero-3-phosphoethanolamine (D-GPE) differs distinctly from that of 1-alkenyl-2-acyl-sn-glycero-3-phosphoethanolamine (P-GPE); P-GPE of tectum resembles that of nerve, while D-GPE differs. The acyl group composition of choline glycerophospholipid (CGP) of tectum and nerve differs slightly but significantly. The acyl group composition of serine glycerophospholipid differs from that of D-GPE and CGP and is also different in tectum and nerve. Nerve possesses a higher content of P-GPE than tectum at all three temperatures. The ratio P-GPE/D-GPE + P-GPE increases with a rise in acclimation temperature, while the 1-alkenyl-2-acyl-sn-glycero-3-phosphocholine (P-GPC)/CGP ratio changes significantly only in nerve. An increase in acclimation temperature results in an increase in the content of saturated fatty acids, while the unsaturation index falls. The acyl group composition of tectum resembles that of synaptosomal fractions, while that of nerve is dissimilar to that of myelin. The findings show that acclimation-to-temperature changes include (1) an alteration in the proportion of plasmalogen, and (2) an alteration in the acyl group composition of all phospholipid species analyzed.

Thermal limits for behavioural function and resistance-adaptation of goldfish, Carassius auratus L.

Goldfish were trained to perform a conditioned avoidance response in a shuttle tank at acclimation temperatures between 10 °C and 35 °C. A high level of success (85–100%) was maintained over a relatively wide range of test temperatures, although outside this range the response was rapidly and reversibly blocked. The upper and lower thermal limits for the avoidance response were determined in goldfish acclimated to temperatures between 10 °C and 35 °C. The absolute thermal limits for the avoidance response in goldfish were approximately 3 °C to 42 °C, but the range for individuals was considerably more restricted. Increased acclimation temperature resulted in higher upper and lower thermal limits and thus constitutes a reasonable resistance adaptation. Over the lower range of acclimation temperatures the upper thermal limit showed greater mobility, whereas over the upper range of acclimation temperatures the lower thermal limits showed greater mobility. Goldfish acclimated to 5 °C and 38.5 °C exhibited very reduced % success at their respective acclimation temperatures even though they showed high % success when the same individuals were previously acclimated to less stressful temperatures. These extreme acclimation temperatures probably represent the absolute limits for chronic exposure.

Enzyme changes accompanying thermal acclimation in two species of pleurocerid snails.

Goniobasis cahawbensis is a stream snail that experiences an annual temperature cycle. G. cochliaris is limited in distribution to springs, and their immediate vicinities, which are characterized by nearly constant annual temperatures. The present study sought to determine whether temperature dependent biochemical differences exist that might account for the differential distribution of these congeneric pleurocerid snails. Eight enzymes were examined following acclimation to 10 degrees, 17 degrees and 24 degrees C. No significant temperature dependent qualitative differences in enzyme phenotypes were demonstrable in either species by starch-gel electrophoresis for malate dehydrogenase, glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, phosphoglucomutase, superoxide dismutase and acetyl and butyryl esterases. Significant quantitative differences were observed in three of these enzymes. G. cahawbensis cytosol malate dehydrogenase activity increased significantly with increasing acclimation temperature, while G. cochliaris malate dehydrogenase activity remained unchanged. The activities of glucose-6-phosphate dehydrogenase did not differ significantly between acclimation temperatures for either species; however, the overall activity of both enzymes was significantly higher for G. cochliaris. Appreciable levels of LDH activity were not demonstrable by electrophoresis or enzymatic assay.

Biochemical changes in blowfly flight muscle mitochondria following temperature acclimation

1. 1.|Blowfly mitochondria show temperature acclimation responses in the same way as the whole animal and isolated tissues. 2. 2.|Both state 3 and 4 mitochondrial respiration rates are temperature dependent. 3. 3.|Respiration at a number of different experimental temperatures is difficult to measure reliably by the oxygen electrode method; a spectrophotometric assay is quicker and more accurate. 4. 4.|Assays of glyerophosphate dehydrogenase activity show no transition temperatures. 5. 5.|Assays of glycerophosphate: cytochrome c oxidoreductase activity show transition temperatures dependent upon acclimation temperature. 6. 6.|Analysis of fatty acids from chloroform soluble mitochondrial lipids show significant changes with temperature acclimation: the proportion of palmitoleic acid (16:1) increases in both species of blowfly with increasing acclimation temperature: with decreasing acclimation temperature there is an increase in long chain unsaturated fatty acids.

Thermal Acclimation of A Central Neurone of Helix Aspersa

ABSTRACT The effects of thermal acclimation on the activity of a central autoactive neurone and its temperature dependence were investigated in Helix aspersa. Resting membrane potential was changed by acclimation temperature, but not with a simple relationship: cells from both 30°C-acclimated and 4°C-acclimated groups were more depolarized at 20°C than were control cells (acclimated to 19°C). The input resistance of the neurone decreased as the temperature of acclimation was raised. Rates of change of potential during an action potential decreased with increasing acclimation temperature. Raising the temperature of measurement on the other hand increased dV/dt at a given acclimation temperature. Spike amplitude was little affected. The frequency of spontaneous spike discharge at a given temperature declined with increasing temperature of acclimation but increased with step changes of temperature in a manner suggestive of a compensatory process. All the measured electrical parameters showed a pronounced hysteresis during rewarming after cold block. Upper lethal and cold block temperatures were both significantly raised by acclimation to higher temperatures. Block temperature was much reduced in cold-acclimated individuals, but the upper lethal temperature was less affected. By sampling during the acclimation period of 4 weeks, the above changes were shown to occur progressively. During the initial stages (5–12 days) they could be partially reversed by incubating isolated ganglia at various temperatures for 30–45 min: but after 2 weeks or more the changes could not be reversed by incubations of up to 5 h.

The effect of the rate of change of temperature on the resistance of Asellus aquaticus (L.) to high lethal temperatures

1. 1.|The heat resistance of adult Asellus aquaticus increased with increasing acclimation temperature. 2. 2.|20°C acclimated animals heated to 35°C at a rate of 1°C per 4 min were less resistant at 35°C than similar individuals placed directly at 35°C. Similarly acclimated animals which were slowly heated to 30°c and then suddenly placed at 35°C showed increased heat acclimation in the more resistant individuals. 3. 3.|The results indicate that when 20°C acclimated individuals are subjected to a steadily rising temperature, further acclimation takes place (especially in the more resistant individuals). When 30°C is reached a little further acclimation takes place in heat sensitive individuals. Above 30°C the animals are adversely affected and this becomes progressively more marked as 35°C is approached.

Adjustment of the components of energy balance in the gastropod Crepidula fornicata in response to thermal acclimation

Synchronous measurements were made of the routine rate of oxygen consumption and the clearance rate of Phaeodactylum tricornutum at different exposure temperatures by specimens of the suspension-feeding gastropod Crepidula fornicata which had been acclimated to temperatures between 10° and 25°C. The results show that the cost of activity (μl O2 consumed h-1/ml seawater cleared h-1) increases dramatically in individuals exposed to short-term increases of temperature up to 30°C, especially in limpets acclimated to 10°C. The process of thermal acclimation, however, results in two compensatory adjustments in energy expenditure and uptake which profoundly affect the energetics of water transport. Firstly, the routine oxygen consumption shows lateral translation of the rate-temperature curve which results in the maintenance of a relatively uniform energy expenditure despite an increase in acclimation temperature from 10° to 25°C. Secondly, because of the form of the rate-temperature curve for filtration by C. fornicata, lateral translation in response to warm acclimation results in an increase in the maximal clearance rate. Lateral translation of the rate-temperature curves for feeding rates and for oxygen consumption in response to thermal acclimation may thus be linked to maintain a balance between energy gain and expenditure. In this way, the greatly increased cost of activity which would occur with increase of temperature in the absence of acclimation is evaded. The minimal maintenance energy requirement, and hence the greatest scope for growth and reproduction, is then adjusted to coincide with temperatures prevailing in the environment.

Metabolic adaptations in brown adipose tissue of the hamster in extreme ambient temperatures.

Cold acclimation caused the following changes in the brown adipose tissue (BAT) of the hamster: the relative weight of the tissue increased, it color darkened, the multilocular structure predominated, and tissue protein content increased while fat content decreased. There was also an increase in the mitochondrial protein content. Heat acclimation had the opposite effects, i.e., the color became lighter, total and mitochondrial protein decreased, fat content increased, and tissue structure was mostly unilocular. Accordingly, cold acclimation was accompanied by increased tissue respiration in the presence of chi-glycerophosphate (chi-GP) and succinate, whereas heat acclimation reduced the respiratory activity of the tissue with these substrates. Isolated BAT mitochondria from cold-acclimated animals increased activities of chi-GP and NADH oxidase, whereas the activities of succinic and cytochrome oxidases and the amount of mitochondrial cytochromes were unchanged. The effects of heat acclimation were more pronounced: there was a decrease in the activities of chi-GP, succinic, NADH, and cytochrome oxidases, as well as in the cytochrome a and a3 content. When respiration of tissue slices on succinate was compared to the maximal potential respiration, as measured with mitochondria disrupted by freezing and thawing, it was found that the relative activity (slices vs. disrupted mitochondria) was highest in cold-acclimated animals and decreased progressively with increasing acclimation temperatures. It is suggested that the differences in the apparent activity of the mitochondria were due to changes in the conformation of the mitochondria as a result of acclimation.

Thermal Tolerances of Dragonfly Nymphs. I. Sources of Variation in Estimating Critical Thermal Maximum

Thermal tolerance was determined for two species of dragonfly nymphs, Libellula auripennis from a thermal effluent stream, and Macromia illinoiensis from a thermal recovery stream. Tolerances were measured at acclimation temperatures of 16, 24, and 32 C under different laboratory conditions. The major source of variation in thermal tolerance was acclimation temperature, which accounted for approximately one-third of the overall variation. Body size, investigator, rate of heating, species, time of day, and number of individuals per test flask had significant effects on thermal tolerance. Aeration of the test water was not a significant variable. Increasing acclimation temperature increased thermal tolerance in both species. Libellula nymphs acclimated at 16 and 24 C exhibited a daily cycle in thermal tolerance with a peak during midafternoon (1400-1600 h). Libellula nymphs acclimated at 32 C, and Macromia nymphs at all acclimation temperatures exhibited no daily cycle in thermal tolerance.