Thermoregulatory behaviour, diel activity and the relationship of spontaneous locomotor activity to temperature in the sea raven, Hemitripterus americanus (Gmelin)

Twelve sea ravens, Hemitripterus americanus , were tested individually for three day periods in electronic shuttleboxes to measure their preferred and avoided temperatures, diel activity pattern and relationship of activity to temperature. The fish avoided temperatures below 9°C or above 25°C, preferring temperatures with a central tendency of 15–17°C. The fish were primarily nocturnal, being more active at night than by day. Locomotor activity increased eightfold between 10 and 20°C, but exhibited an anomalous decrease between 14 and 18°C, corresponding to the preferred-temperature zone, characteristic of maximal summer temperatures in the natural habitat.     

Climatic influence on mesophilic Bacillus cereus and psychrotolerant Bacillus weihenstephanensis populations in tropical, temperate and alpine soil

Bacillus weihenstephanensis strains are psychrotolerant and grow from below 7°C to 38°C. Closely related mesophilic Bacillus cereus strains can grow from above 7°C to 46°C. We classified 1060 B. cereus group isolates from different soil samples with respect to their psychrotolerant and mesophilic genotypes by polymerase chain reaction (PCR) targeting of specific 16S rDNA and cold shock protein A gene signatures. In parallel, growth tests at 7°C were carried out to determine the thermal phenotype. The geographic distribution of psychrotolerant and mesophilic isolates was found to depend significantly on the prevalent annual average temperature. In one tropical, one temperate and two alpine habitats, the proportion of psychrotolerant cspA genotypes was found to be 0%, 45% and 86% and 98%, respectively, with the corresponding annual average temperatures being 28°C, 7°C, 4°C and 1°C. In the tropical habitat, only the mesophilic B. cereus was found, characterized by correspondence of thermal genotype and phenotype. In the alpine habitat, almost only the psychrotolerant B. weihenstephanensis was isolated. In the temperate habitat, mesophilic B. cereus and psychrotolerant B. weihenstephanensis as well as 'intermediate thermal types' occurred, the latter having opposite thermal genotypes and phenotypes or opposing sets of thermal DNA signatures, characterized by the coexistence of mesophilic and psychrotolerant 16S rDNA operon copies within a single isolate. Both sugar utilization and DNA fingerprinting patterns revealed a high, probably non-clonal microsite diversity within the population of the temperate habitat. We interpret our observations in terms of a temperature-dependent selection regime, acting on recombining B. cereus / B. weihenstephanensis populations in soil.     

Convergence and parallelism among cicadas of Argentina and the southwestern United States (Hemiptera: Cicadoidea)

Cicadas of the genera Derotettix in Argentina and Okanagodes in the south-western United States resemble each other in colour, live on salt-tolerant plants ( Atriplex spp. etc.), nearly match the colour of their respective host plants and produce songs above the range of avian hearing. The Argentine cicadas are smaller, but have nearly identical thermal limits for activity measured by the minimum temperature for flight (20–24 °C) and a body temperature at heat torpor (48–49 °C). The species shift activity from basking sites to shade at temperatures above 37 °C, although O .  gracilis rises to a significantly higher temperature (40.7 °C) than its congener (38.2 °C) or Derotettix (37.2 °C). The thermal tolerances are the highest reported for cicada species. A third group using halophytes in Argentina ( Babras sonorivox ) has similar temperature tolerances and is cryptically coloured. The genera are convergent with respect to morphology, coloration, body size, behaviour, habitat choice and host plant selection. The similarities of thermal tolerances and their influence on behaviour can be viewed as parallelism because the underlying mechanisms are the same in all species studied.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 281–288.     

Time allocation and patterns of activity of the dorcas gazelle (<Emphasis Type="Italic">Gazella dorcas</Emphasis>) in a sahelian habitat

The patterns of activity are a reflection of the adaptation of a species to its habitat. This study reports the patterns of activity and time allocation of the dorcas gazelle following their reintroduction process from the captivity to semi-wild conditions in a sahelian habitat. Activity of three adult males was recorded using GPS collars equipped with a temperature sensor and acceleration sensors recording in two channels, forward–backward (X-axis) and sideways (Y-axis). Collars delivered data for 59, 139 and 151 days. The aim of this work is to assess the ability of dorcas gazelle to adapt its activity schedule to a changing environment. The main activity behaviour observed is resting (59.8 ± 23.9%), followed by feeding (20.9 ± 10.9%), displacement (15.1 ± 14.1%) and running (3.9 ± 5.5%). If resting time is eliminated, the gazelles invest most of their time in feeding (61.0 ± 21.3%) and displacements (30.8 ± 15.6%) and only 7.6 ± 0.6% in running. The dorcas gazelle exhibit three patterns of activity: one diurnal with maximum activity in the central hours of the day, which accounts during the dry-cool season (December, January and February); a bimodal pattern with maximum activity at dust and dark, resting in the middle of the day during the hot-dry season (April) and a transitional pattern in March. Temperature is the main driver of this change in patterns; when average temperature exceeds the body temperature of the dorcas gazelle, the pattern of activity changes from diurnal to bimodal. These results reveal the ability of the dorcas gazelles facing environmental changing conditions in their native habitat.     

Water temperature fluctuations and territoriality in the intertidal zone: two possible explanations for the elevational distribution of body size in Graus nigra

On the central coast of Chile, distribution of body size in Graus nigra varied with tidal pool height. With the objective of determining whether environmental temperature is one of the possible causes which explains the observed distribution pattern, two behavioural responses were analysed during an experimental period of increasing water temperature: number of opercular movements (an indirect measure of energy expenditure) and activity levels. The interactions of temperature × time and body size × time had a significant effect on the number of opercular movements. At low temperatures (13–15° C), large fish reached a maximum number of opercular movements, while small fish reached a maximum only at high temperatures (23–25° C). The interaction temperature × time had a significant effect on activity levels of different body sizes. In general, large fish appeared to be less active than small fish, however, at very high temperatures (24–26° C) all individuals increased their activity levels. These data indicate that small fish are acclimatized to live in a wider range of temperatures (13–23° C), and, for fish of all body sizes, the highest temperatures (23–26° C) probably constitute a suboptimal microhabitat. Strong territoriality was observed, with large individuals displacing smaller individuals. These data suggest that temperature is an important factor in explaining why large individuals are not present in high tidal pools (high temperatures), whereas territoriality explains why small individuals are not in low tidal pools (habitat of large individuals).     

Temperature effects in relation to the patterns of distribution and abundance of three species in the Drosophila affinis subgroup

Abstract. 1. The effect of temperature on several aspects of the biology of Drosophila affinis, D.algonquin and D.athabasca were investigated in order to gain insight as to why these closely related species differ in their spatial and temporal patterns of occurrence.
2. No differences exist between the three species in the effect of temperature on egg hatchability.
3. Productivities of the three species were measured in a temperature gradient device. These measurements indicated that D.athabasca has an advantage in productivity over D.affinis at cooler temperatures (below 25°C). At warmer temperatures (above 25°C) the greater productivity of D.affinis makes it the better species. Drosophila algonquin , like D.athabasca , was characterized by its productivity curve as a species more adapted to cooler climates.
4. The competitive abilities of the three species were measured at 25°C, at 18°C, and in an environment which fluctuated between 18 and 25°C on a daily cycle. Competitive ability was estimated on the basis of the performance of the species in two- and three-species populations.
5. In general, D.affinis exhibited its highest competitive ability relative to the other two species at the highest experimental temperature. D.athabasca had its highest competitive ability at the lowest temperature. The competitive ability of Ddgonquin was intermediate; less than that of D.affinis but greater than D.athabasca .
6. The dependence of competitive ability and productivity on temperature is thought to be partly responsible for the differences between the species with respect to their geographic distributions and their spatial and temporal patterns in natural populations.     

A "CELL-CONTACT TEMPERATURE-SENSITIVE" MUTANT OF THE CELLULAR SLIME MOLD DICTYOSTELIUM MUCOROIDES

A mutant (TS-2) that is temperature-sensitive with respect to cell contact was isolated from the cellular slime mold, Dictyostelium mucoroides. The TS-2 were able to grow and develop normally at 21°C, but unable to grow at 31.5°C. When TS-2 were allowed to develop until the aggregation stage at 21°C and then shifted to 31.5°C, they instantly lost cell-to-cell contact, resulting in disintegration of the aggregation stream and flattening of the aggregation center. Although a slug transferred to 31.5°C retained its original shape, loss of cell-to-cell contact within the cell mass was evidenced by several facts. The TS-2 interphase amebas, at 31.5°C, also lost cell-to-substratum contact, and the loss of contact was followed by the production of cell-wall substance on their surface. The production of the same substance at 31.5°C was also observed in cells at aggregation and migration stages, but not in those at the vegetative stage. When TS-2 cells at various developmental stages were kept at 31.5°C for various periods of time and returned to 21°C they lost morphogenetic capacity in proportion to the production of the cell-wall substance.     

Summer quiescent behaviour of the millipede Ommatoiulus moreleti (Julida: Julidae)

The millipede Ommatoiulus moreleti (Lucas), (Julidae) originates in the south-west Iberian Peninsula, and has successfully invaded parts of southern Australia with hot, dry summers. The species is inactive in the field during summer but is active in autumn, particularly following rains, and in spring. There is some activity in winter. In this paper, the temperature and humidity determinants of seasonal behaviour are analysed, in particular the conditions causing summer quiescence.
Experiments using a millipede treadmill apparatus at different temperatures at 95% RH showed an almost linear response of locomotor activity with temperature between 3 and 21°C, but when the temperature was increased to 28°C, the millipedes became quiescent. Activity could he restored by reducing the temperature.
When the millipedes were exposed to 45% RH there was comparatively little activity at any temperature. Field evidence indicates ii rapid breaking of quiescence with surface moisture
The success of O. moreleti in invading the surface-litter habitat in South Australia can he explained by its ability to avoid desiccation; its adaptations include its quiescent behaviour during summer and its ability to moult from a winter (reproductive) to B summer (non-reproductive) form.     

Coastal–marine discontinuities, critical patch size and isolation: implications for marine otter conservation

The consequences of habitat fragmentation include reduced habitat availability, increased isolation and patch extinction. This study investigates the occupancy patterns of Lontra felina , a little known and endangered marine otter, on naturally discontinuous habitat and the relationship between otter occupancy and rocky seashore patches, patch size and isolation and human influences. Marine otter occupancy was determined through direct sightings and the presence/absence of spraints, and measured by logistic regression and general linear models. The study was conducted in Chile between 28°S and 40°S, and consisted of eight study sites. Within these sites, a total of 23 rocky seashore patches, 2.3–63.8 km long, were surveyed from January 2005 to March 2006. The strongest predictors of marine otter occurrence were rocky seashore patches larger than 5 km long and <6 km apart. These networks should be no farther than 20 km from contiguous (without sandy beaches) rocky seashore patches over 15 km long.     

A continuously recording respirometer, used to measure oxygen consumption and estimate locomotor activity in tsetse flies, Glossina morsitans

ABSTRACT. The construction of a continuously recording respirometer is described. The oxygen consumption patterns of male tsetse flies recorded with this apparatus generally match their patterns of locomotor activity previously reported from actograph data and direct observation. Clear signs of a diel rhythm, in a light cycle, were still apparent at the low temperature of 15°C.     

Effect of sub-optimal temperatures on survival of mammalian cells

When survival at low temperatures, in terms of colony-forming ability, is measured in Chinese hamster lung cells (V79), it varies inversely with temperature in the 10–25 °C range; i.e. survival at 10 °C is greater than that at 25 °C. These survival-time curves on semi-log plots have a “shoulder” region followed by a linear region. Survival at these temperatures varies inversely with the macromolecular synthesis rate. Results with cells at 5 °C break the above patterns.     

Thermal tolerance and heat shock protein synthesis during development in the anuran Lepidobatrachus laevis

Development of the Paraguayan anuran Lepidobatrachus laevis is unusual in that the larvae are obligate carnivores, facultative cannibals and apparently exist at high environmental temperatures in their natural habitat. In the present study, the effect of environmental temperature on the rate of anuran development was investigated. The larvae have a thermotolerance range of 18°C for normal development between 19 and 37°C. The effect of temperature on the rate of development was dramatic; larvae that were incubated at 36.8°C develop to stage 24 (Gosner) in approximately 9 h compared with 24 h for larvae incubated at 19°C. The ability of larvae to survive heat shock was also examined; larvae did not survive a shock of 45°C for 15 min when it was administered at stages 3, 5, 9, 10 or 20. However, using the same heat shock conditions, 50% survival was observed when larvae were shocked at stage 16. To study protein synthesis during heat shock, larvae were pulsed with [³⁵S]-methionine during heat shock and labeled proteins were analyzed by electrophoresis under reducing and denaturing conditions. Larvae synthesized two sets of heat-shock proteins at doublet molecular weights of 83/78 and 62/59 kDa. These proteins were synthesized independently of the stage of development at which the shock was administered or the magnitude of the heat shock.     

The influence of thermoregulation on behavioural recovery from exercise in a lizard

1. Past work on the thermal preferences of Dipsosaurus dorsalis (Biard & Giard) has indicated that intense, exhaustive exercise causes these lizards to select a body temperature (33·5 °C) which is cooler than their preferred activity temperature of 40°C during the first 1–2 h of exercise recovery.
2. In order to test the hypothesis that the thermal regime selected by exhausted D. dorsalis is beneficial to the process of exercise recovery, lizards were forced to undergo both exhaustive and sprinting exercise at their preferred body temperature of 40°C. The peak speeds attained and the total distances travelled by these animals during these two different exercise protocols were measured and the animals were then forced to undergo a second bout of either sprinting or exhaustive exercise, following a 30–330 min recovery at either 20°C, 40°C or under a variable thermal regime which duplicated that selected by animals following exercise.
3. Animals recovering at a constant 40°C regained their ability to repeat exhaustive activity in less than 85 min, while animals recovering under the other two thermal regimes required between 85 and 100 min of recovery to be able to repeat this activity. Animals recovering at both 40°C and under the variable thermal regime regained their ability to repeat sprint behaviour within 60 min of recovery, while animals recovering at 20°C required more than 100 min of recovery to be able to repeat sprint behaviour.
4. These results formed the basis of the conclusion that the post-exercise behaviour selected by D. dorsalis retards the rate at which the animals recover their ability to repeat exhaustive exercise when compared with recovery at a constant 40°C but does not retard their ability to repeat sprint exercise.     

Potential fragmentation and loss of thermal habitats for charrs in the Japanese archipelago due to climatic warming

1. The upper thermal limits of the present distributions of two charr species, Dolly Varden, Salvelinus malma , and white-spotted charr, S. leucomaenis , in streams of the Japanese archipelago were examined using groundwater temperature as an index of thermal condition. The lower limits of the altitudinal distributions of Dolly Varden and white-spotted charr were delineated, respectively, by 8 and 16 °C groundwater isotherms.
2. The potential impact of future climatic warming on the geographical distribution, habitat extent and population fragmentation of each species was predicted at both the full archipelago and individual catchment levels.
3. For Dolly Varden, analysis at the full archipelago level indicated a loss of 27.6, 67.2, 79.6 and 89.6% of the current geographical range, respectively, for a 1, 2, 3 and 4 °C increase in mean annual air temperature. The present distribution area of white-spotted charr would likewise reduce by 4.1, 20.5, 33.8 and 45.6%, respectively.
4. Based on the analyses of three individual catchments, one for Dolly Varden and two for white-spotted charr, the lower habitat boundaries for the two charr species could be expected to rise increasingly to higher elevations in each catchment as warming proceeded. As a consequence, there would be large reductions in mean habitat area, with increasing habitat fragmentation followed by localized extinctions of the two species.     

Potential fragmentation and loss of thermal habitats for charrs in the Japanese archipelago due to climatic warming

1. The upper thermal limits of the present distributions of two charr species, Dolly Varden, Salvelinus malma , and white-spotted charr, S. leucomaenis , in streams of the Japanese archipelago were examined using groundwater temperature as an index of thermal condition. The lower limits of the altitudinal distributions of Dolly Varden and white-spotted charr were delineated, respectively, by 8 and 16 °C groundwater isotherms.
2. The potential impact of future climatic warming on the geographical distribution, habitat extent and population fragmentation of each species was predicted at both the full archipelago and individual catchment levels.
3. For Dolly Varden, analysis at the full archipelago level indicated a loss of 27.6, 67.2, 79.6 and 89.6% of the current geographical range, respectively, for a 1, 2, 3 and 4 °C increase in mean annual air temperature. The present distribution area of white-spotted charr would likewise reduce by 4.1, 20.5, 33.8 and 45.6%, respectively.
4. Based on the analyses of three individual catchments, one for Dolly Varden and two for white-spotted charr, the lower habitat boundaries for the two charr species could be expected to rise increasingly to higher elevations in each catchment as warming proceeded. As a consequence, there would be large reductions in mean habitat area, with increasing habitat fragmentation followed by localized extinctions of the two species.     

Rapid small scale preparation of bacterial genomic DNA, suitable for cloning and hybridization analysis

The uptake of noxythiolin by a urinary isolate of Escherichia coli was examined initially at 37°C but the adsorption isotherm was complicated by the concomitant degradation of the compound. When drug adsorption was investigated at 4°C, to reduce the degradation rate of the compound, it was observed that noxythiolin was taken up by the urinary isolate in a linear fashion. The resulting adsorption patterns are discussed in relation to their possible classification. The implications of this uptake are considered with respect to the antimicrobial activity of noxythiolin.     

An evaluation of gene expression during somatic embryogenesis of two temperature-sensitive carrot variants unable to complete embryo development

The synthesis of putative stage-specific polypeptides during somatic embryogenesis of the carrot ( Daucus carota L. cv. Danvers) was investigated in the temperature-sensitive variants OB-2 and OB-3. These variants undergo normal embryo development to produce mature plantlets at the permissive temperature (24°C), but are arrested at the oblong stage to form elongated embryos without cotyledons at the restrictive temperature (33°C). Using two-dimensional polyacrylamide gel electrophoresis of in vivo labelled polypeptides, the patterns of stage-specific polypeptides in both lines were compared in: (1) oblong embryos grown at continuous 24°C vs oblong embryos exposed to 33°C during their temperature-sensitive period (i.e. embryos of identical morphology but different developmental fates); and (2) heartshaped embryos grown at constant 24°C vs enlarged oblong embryos exposed to 33°C during their temperature-sensitive period (i.e. embryos of the same age but different morphologies). The 22 putative stage-specific, polypeptides observed in this study fall into four classes: (1) line-specific, (2) age-specific, (3) unsynchronized, and (4) synchronized polypeptides. Only the last class, which consists of 4 polypeptides, exhibits synthesis patterns which are consistent with the polypeptides being causally involved in somatic embryo development. It is concluded that stage-specific behavior as assayed by PAGE analyses of simple 'present or absent' comparisons is insufficient to identify most of the polypeptides that may be relevant for somatic embryogenesis.     

Diurnal activity patterns of coypu in an urban habitat

The ability of species to adapt to changing environmental conditions is a crucial need for surviving in human influenced landscapes. Especially non-indigenous species, which are flexible in their behaviour, may successfully enter and establish in new habitats. We compared the activity patterns of the invasive coypuMyocastor coypus (Molina, 1782) in an urban habitat in Germany with patterns observed in its native distribution range in South America as well as in areas, where it was introduced. In summer 1998 and winter 1999 a radio tracking study was carried out on six adult coypus, supplemented by count data on untagged animals. Whereas main activity in non-urban populations was recorded at night including dusk and dawn, coypus in the urban habitat were active during the day and early evening. We never observed animals between midnight and dawn. This reversal of activity patterns is attributable to deposition of human food in the city area during the daytime.     

Effect of predator size and temperature on the predation of Deroceras reticulatum (Muller) (Mollusca) by carabid beetles

Twenty-one carabid species were used in a laboratory study to determine the effect of beetle size and temperature on the predation of one day old Deroceras reticulatum (Muller) slugs. The beetles were caught in arable land at the study site. None of the five small-sized beetle species killed slugs, whereas five of the seven medium-sized beetle species and eight of the nine large-sized beetle species killed slugs. Four of the most abundant beetle species at the study site were used to assess the effect of temperature on the predation of 1-day-old slugs. There were significant differences in the proportion of beetles predating slugs at the different temperatures. Regression analysis showed that there was a significant increase in the proportion of Pterostichus madidus (Fabricius) and Harpalus rufipes (Degeer) beetles predating slugs as temperature increased. Nebria brevicollis (Fabricius) inflicted its highest level of slug mortality at 8°C and its larvae were the only predators to significantly increase slug mortality at 4°C, the lowest experimental temperature. Harpalus aeneus (Fabricius) inflicted significant levels of slug mortality at 20°C, the highest experimental temperature. It appeared that the predatory activity of these beetle species at the five experimental temperatures reflected their annual activity periods in the field.