Previous Acclimation Temperature Research Articles

Temperature preference and acclimation in the Jonah Crab, Cancer borealis

Temperature indisputably affects the physiology of poikilotherms. The role of temperature and its impacts on crustacean heart rate, internal pH and nervous system activity, have been characterized. Whether a species acts to seek or avoid particular temperatures to optimize a particular physiological character is less well understood. This study addresses the thermoregulatory behavior of the Jonah crab (Cancer borealis), a decapod crustacean that is economically valuable as an emerging fishery and also of importance as both a key species in intertidal and subtidal communities and a model organism for rhythmic pattern generating nervous systems. Using acclimation to temperatures within the range of those normally inhabited in summer months (11°C, 14.5°C, 20°C) and then conducting behavioral assays in a thermal gradient tank, this experiment characterized the thermotactic responses of the Jonah crab. Results indicate Cancer borealis will behaviorally thermoregulate and adjust the direction and magnitude of its movements towards a preferred temperature range. Moreover, the preferred temperature ranges of this species are significantly impacted by previous acclimation temperature.

Thermal acclimation and stress in the American lobster, Homarus americanus: equivalent temperature shifts elicit unique gene expression patterns for molecular chaperones and polyubiquitin

Using homologous molecular probes, we examined the influence of equivalent temperature shifts on the in vivo expression of genes coding for a constitutive heat shock protein (Hsc70), heat shock proteins (Hsps) (Hsp70 and Hsp90), and polyubiquitin, after acclimation in the American lobster, Homarus americanus. We acclimated sibling, intermolt, juvenile male lobsters to thermal regimes experienced during overwintering conditions (0.4 +/- 0.3 degrees C), and to ambient Pacific Ocean temperatures (13.6 +/- 1.2 degrees C), for 4-5 weeks. Both groups were subjected to an acute thermal stress of 13.0 degrees C, a temperature shift previously found to elicit a robust heat shock response in ambient-acclimated lobsters. Animals were examined after several durations of acute heat shock (0.25-2 hours) and after several recovery periods (2-48 hours) at the previous acclimation temperature, following a 2-hour heat shock. Significant inductions in Hsp70, Hsp90, and polyubiquitin messenger RNA (mRNA) levels were found for the ambient-acclimated group. Alternatively, for the cold-acclimated group, an acute thermal stress over an equivalent interval resulted in no induction in mRNA levels for any of the genes examined. For the ambient-acclimated group, measurements of polyubiquitin mRNA levels showed that hepatopancreas, a digestive tissue, incurred greater irreversible protein damage relative to the abdominal muscle, a tissue possessing superior stability over the thermal intervals tested.

Upper temperature tolerances of some European molluscs

The upper temperature tolerances of three European species of Cardium [C. (Cerastoderma) glaucum Bruguiere, C. tuberculatum L., C. (Cerastoderma) edule L.] are compared by means of median lethal temperature (LT50) and median burial temperature (BT50) determinations for periods of exposure up to 96 h. The influence of previous acclimation temperatures on these determinations is also considered. C. glaucum from shallow water (0.5 to 1 m), lagoonal, habitats in the Mediterranean Sea shows a greater thermal tolerance than C. tuberculatum from deeper water (4 to 5 m) in the Mediterranean. The thermal tolerance of C. edule from the intertidal zone, but at higher latitudes, is intermediate. Young C. glaucum show a greater resistance to short exposures to high temperatures than adults, but for longer exposures their tolerance is the same. All 3 species exhibit a significant effect of previous acclimation temperature on the burrowing response, and C. glaucum and C. tuberculatum a significant but lesser effect on LT50. LT50 determinations with C. edule showed secondary mortality effects which may have obscured any effect of acclimation temperature.

Upper temperature tolerances of some European molluscs II. Donax vittatus, D. semistriatus and D. trunculus

The upper temperature tolerances of 3 European species of Donax [D. vittatus (da Costa), D. semistriatus Poli, D. trunculus L.] are compared by means of median lethal temperatures (LT50) and median burial temperature (BT50) determinations for periods of exposure up to 96 h. The influence of previous acclimation temperatures on these determinations is also considered. D. trunculus shows the greatest thermal tolerance, reflecting its distribution in shallower water; D. vittatus and D. semistriatus display much closer thermal tolerances, although D. semistriatus which has a more southerly geographical distribution has a slightly higher thermal tolerance. All 3 species exhibit a significant effect of previous acclimation temperature, the effect on the burrowing responses being greater than that on LT50.

Upper temperature tolerances of some European molluscs. I Tellina fabula and T. tenuis

The upper temperature tolerances of two European species of Tellina from populations near the northern and southern limits of their geographical range are compared by means of median lethal temperature (LT50), and median burial temperature (BT50) determination for periods of exposure up to 96 h. The influence of previous acclimation temperature, and salinity within a limited range, on these determinations is also considered. T. fabula Gmelin, which is found in deeper water throughout its range, shows a lower thermal tolerance than T. tenuis da Costa. Both species display a significant effect of previous acclimation temperatures, the effect on the burrowing responses being greater than that shown by LT50, and in both species the thermal tolerance of individuals from Mediterranean populations is greater than that of individuals from North Atlantic populations.

Bioassays on the combined effects of chlorine, heavy metals and temperature on fishes and fish food organisms. Part I. Effects of chlorine and temperature on juvenile brook trout (Salvelinus fontinolis).

Groups of Eastern brook trout, Salvelinus fontinalis, were acclimated to four temperatures (7, 10, 15, or 20/sup 0/C) for two weeks; however, due to disease problems the 20/sup 0/C group was discarded after bioassay number 2. Separate subsamples of each acclimation group were exposed to a range of chlorine values at three temperatures (10, 15, 20/sup 0/C). There was no significant difference between the 96-hr mortality values at 10 or 15/sup 0/C regardless of previous acclimation temperature. However, in fish exposed to 20/sup 0/C test temperature, all 96-hr LC50 values were significantly less than at the lower test temperatures. The lower 96-hr LC50 values at the 20/sup 0/C test temperature were also independent of acclimation temperature. Differences were also observed between early mortality and 96 hr mortality. Groups that had experienced the greater temperature change from acclimation, experienced the higher mortality, regardless of whether the change was an increase or decrease. (ND)

Neuronal change: Compensatory acclimation of the contribution of an electrogenic pump to the resting potential

1. The resting potential of the lateral giant neuron in the buccal ganglia of the fresh water snailHelisoma trivolvis becomes more negative with an increase in temperature (Fig. 1). 2. The degree to which the resting potential varies over 3 to 30° C is dependent upon the previous acclimation temperature of the experimental subject (Fig. 6A). 3. Temperature acclimation (at 5 and 25° C) partially compensates for the temperature dependence of the resting potential. 4. The resting potential can be dissected into ionic permeability and metabolic pump components by the use of ouabain, a specific inhibitor of sodium pump activity (Fig. 2). The contribution of the sodium pump to the resting potential is found to be the main component responsible for the resting potential acclimation (Fig. 6B). 5. Such compensatory temperature acclimation would enable the lateral giant neuron to maintain its function as effector of salivary gland activity over a wide range of environmental temperatures.

The effect of temperature on transmission at the neuromuscular junction of the sartorius muscle of Rana pipiens

1. 1. The neuromuscular junction of the frog was more readily blocked by cold than either the nerve or the muscle, and was blocked at 1°C for 10°C-acclimated frogs and at 4°C for 25°C-acclimated frogs. 2. 2. Endplate potentials recorded intracellularly as a function of temperature in curarized muscles showed an attenuation of amplitude at low temperatures; for 10°C-acclimated frogs, the response at 1°C averaged approximately 70 per cent of the response at 24°C. 3. 3. Miniature endplate potentials showed an increase in amplitude at intermediate temperatures of about 17-12°C, and a decrease in amplitude upon further cooling. Post-junctional depolarization in response to microperfusion of acetylcholine also went through a maximum at the intermediate temperature range of 20-10°C, and the temperature at which this maximum response occurred was dependent upon the previous acclimation temperature. 4. 4. Low temperature (7–8°C) decreased facilitation of endplate potentials in curarized muscles at high frequencies of stimulation (30 c/s), while it increased the facilitation at low frequencies (10 c/s), when compared to facilitation at high temperature (16°C).

Acutely measured metabolic rate-temperature curves in the cricket frog, Acris crepitans

1. 1. Measurements of oxygen consumption were made at 5°C intervals between 5 and 35°C on frogs acclimated in the dark at temperatures of 5, 15 and 25°C. 2. 2. Inverse compensation is the rule at determination temperatures below 30°C. Between 15 and 25°C the frogs acclimated at 25°C respond metabolically as warm-acclimated animals and the 5 and 15°C frogs respond as cold-acclimated animals. At 5°C the frogs acclimated at 15°C respond as warm-acclimated animals. 3. 3. At determination temperatures of 30 and 35°C metabolic rates are not influenced by previous acclimation temperatures (routine rates) or partial compensation occurs (standard rates). 4. 4. The acclimated rate-temperature curves show no indication of temperature compensation.

Choline acetyltransferase activity in the brain of goldfish acclimated to different temperatures

1. 1. The effect of temperature acclimation on acetylcholine (ACh) synthesis by goldfish brain homogenates prepared from fish acclimated to 8, 15, 25 and 32°C has been investigated. 2. 2. The enzyme responsible for ACh synthesis, choline acetyltransferase, is stable at incubation temperatures higher than previous acclimation temperatures. 3. 3. The activity of the enzyme is greater at higher acclimation temperatures. There was no evident difference in the kinetic properties of the enzyme measured at high incubation temperatures, 39–45°C. 4. 4. At lower incubation temperatures, 15–25°C, the kinetic constants did vary suggesting possible differences in enzyme properties.