Behavioral response of the New England dog whelk,Nassarius trivittatus,to a temperature gradient

Thirty New England dog whelks (Mollusca: Gastropoda: Nassariidae), Nassarius trivittatus, were tested as a group for 3 days in a long linear gradient trough encompassing a thermal gradient ranging from 5°C to 45°C. The modal thermal preferendum of the snails lay between 30°C and 35°C. The lowest temperature interval voluntarily occupied by the snails was 15–20°C, the highest 35–40°C. W e believe this to be the first published study of temperature preference and avoidance behavior of gastropod molluscs.     

Development of the starfish <Emphasis Type="Italic">Asterias amurensis</Emphasis> under laboratory conditions

Under laboratory conditions the development of the starfish Asterias amurensis Lütken from Vostok Bay (Sea of Japan) was studied at 14 and 17°C. At 14°C and a salinity of 31.6–32.6, ciliated coeloblastulae hatched from egg envelopes 19 h after fertilization. At this temperature the development proceeded slowly and stopped at the stage of bipinnaria. At 17°C and normal salinity of seawater, the development of A. amurensis was successful. The swimming blastula appeared in 14 h. It took 30.5 h for the embryos to reach the gastrula stage. The larvae began swimming in a horizontal position with the apical tip ahead. The dipleurula appeared at 60 h. These larvae began feeding. At 71 h after the beginning of development, the early bipinnaria has developed. In the larva, the edged ciliated band, the preoral plate, and the anal plate were already formed. At the age of 4.2 days, the larvae reached the stage of bipinnaria and the brachiolaria stage developed by 26–28 days after fertilization. The larvae had three identical brachiolar arms with attachment papillae on their tips and an attachment disk. In 37–44 days (at 17°C) the pelagic phase of A. amurensis development was completed by the attachment of larvae to the bottom plates and termination of metamorphosis. Most likely, the specificity to a substrate is not expressed in the brachiolaria of A. amurensis. They can settle on almost any hard substrate which is coated with a bacterial film. The newly settled juvenile starfish had five well-developed arms and moved using their ambulacral podia.Original Russian Text Copyright © 2005 by Biologiya Morya, Kashenko.     

Chronology of Development in the Starfish <Emphasis Type="Italic">Asterina pectinifera</Emphasis> from Vostok Bay,Sea of Japan

The development of the starfish Asterina (= Patiria) pectinifera (Muller et Troschel) from fertilization to metamorphosis took 27–28 days at 22°C and a salinity of 33–33.4‰. The embryonic development was completed by the release of swimming ciliary blastula from egg envelopes 13 h after fertilization. The larvae passed into the stage of gastrula and reached the stage of dipleurula in 35 h and the stage of bipinnaria in 3.5 days. At the stage of brachiolaria, by the 12th day of development, two lateral brachioles and one medioventral brachiole with papillae developed in the larvae. The attachment disk and the primordia of five radial canals of the juvenile starfish became visible by the 15th and 18th days, respectively. By the 24th–25th day, a differentiated primordium of a juvenile starfish had developed in the brachiolaria. The size of the larvae prior to settlement was 1765.4 ± 51.5 µm. Metamorphosis was completed one day after settlement.Original Russian Text Copyright ¢ 2005 by Biologiya Morya, Kashenko.     

Developmental Time of <Emphasis Type="Italic">Blattisocius Tarsalis</Emphasis> (Acari: Ascidae) at Different Temperatures

The developmental time of the predatory mite Blattisocius tarsalis (Berlese) (Acari: Ascidae) was investigated at temperatures of 15, 21 and 25°C and 75% r.h. Eggs 1–3 days old of Ephestia kuehniella Zeller (Lep.: Pyralidae), killed by freezing, were used as food. Mean developmental times were found to be 22.4, 8.5 and 7.0 days, respectively. Within the investigated thermal limits the developmental rate showed a linear relationship with temperature and the corresponding thermal threshold for development was calculated to 10.2°C.     

Temperature preferences and tolerances of three fish species inhabiting hyperthermal ponds on mangrove islands

The fish species Cyprinidon artifrons, Floridichthys carpio, and Gambusia yucatana inhabit shallow mangrove ponds off the coast of Belize. Portions of these ponds experience a diurnal temperature change from 26 °C at night to 40 °C and above during midday. Repeated field observations indicate Cyprinidon prefer the warmer (and much larger) portions of the ponds whereas the other two species stay in the cooler areas.The hypothesis that temperature is serving as a cue for partitioning within the ponds was supported by laboratory thermal gradient tests in which Cyprinidon preferred temperatures clearly higher than the other two species.The critical thermal maximum (CTM) was determined for the three species using members that had been acclimated to either a daily cycling temperature similar to that for the ponds, or to the mean of the 24-hour cycle (30 °C). Cyprinidon acclimated to the cycling temperature had a CTM of 45.5 °C, which apparently sets a new record for fish CTM. Acclimation to a constant 30 °C lowered the CTM to 43.7 °C. Floridichthys and Gambusia acclimated to the cycled temperature had CTMs of 43.9 and 43.3 °C respectively, and 42.5 and 42.6 °C for those acclimated to 30 °C.All three species appear to have the ability to tolerate the high temperatures throughout the ponds but only Cyprinidon utilize the whole pond during the day. This may help to explain the large populations of Cyprinodon found in these mangrove ponds compared to the other species.     

Life-history traits of the acarophagous lady beetle,<Emphasis Type="Italic">Stethorus japonicus</Emphasis> at three constant temperatures

Stethorus japonicusKamiya (Coleoptera: Coccinellidae) is an indigenous ladybird beetle in Japan, which feeds on many spider mite species. We evaluated the development, survivorship and life-history parameters of this lady beetle on a diet of eggs of the two-spotted spider mite, Tetranychus urticae Koch (red form) (Acari: Tetranychidae). In addition, the effect of short photoperiod on its reproduction was assessed. Survival rates from egg to adult were more than 71% at temperatures between 17.5 and 30 °C. The highest immature mortality was 100% at 35 °C followed by 76% at 15 °C and 52% at 32.5 °C. The lower threshold temperature for development from egg to egg-laying adult was 13.0 °C and the thermal constant was calculated as 238.7° days. Based on these data, the maximum number of generations that could complete development in a year under field conditions in Ibaraki, central Japan, would be between five and seven. The intrinsic rates of natural increase (r_m) were 0.093 at 20 °C, 0.156 at 25 °C and 0.241 at 30 °C. Reproductive diapause was induced at photoperiods with light phases shorter than 13 h at 18 °C.     

Thermoregulatory behavior of a tropical marine fish: Canthigaster jactator (Jenkins)

Ten Canthigaster, jactator, tropical marine puffers from Hawaii, were tested individually for 3-day periods in electronic shuttle-boxes (Ichthyotrons) to determine their ability to thermoregulate behaviorally. These fish thermoregulated with a degree of precision comparable to that of temperate freshwater fishes: range 23–31°C, S.D. 1.8–2.4°C, S.E. 0.3–0.5° C. The modal final thermal preferendum was 27°C, comparable to temperate warmwater fishes. The mean preferred temperature did not differ significantly between night (26.5°C) and day (26.9°C); the 24-hr mean was 26.7°C. Apparently at least some tropical marine fishes are capable of thermoregulatory behavior similar to that of temperate freshwater fishes.     

Temperature preferences and oxygen consumption of three species of sculpin (Cottus) from the Pit River drainage,California

Synopsis I examined the temperature preferences and routine metabolic rates of Pit sculpin, Cottius pitensis, marbled sculpin, C. klamathensis macrops, and rough sculpin, C. asperrimus, of the Pit River drainage of California to determine if the distributional patterns of these species can be explained on the basis of physiological or behavioral responses to temperature. The routine metabolic rates of these species did not increase significantly between 10 and 15°C, indicating an area of thermal compensation. Metabolic rates then rapidly increased between 15 and 20°C (Q₁₀ values>4.0) followed by little increase between 20 and 25°C (Q₁₀ values >2.0), indicating another area of thermal compensation. The final temperature preferenda of Pit, marbled and rough sculpin were 11.2, 12.1 and 13.5°C, respectively. Marbled and rough sculpin appear to be more stenothermal than Pit sculpin. At acclimation temperatures of 10, 15 and 20°C the acute preferred temperatures of marbled and rough sculpin ranged from 11.1 to 14.7° C and 13.3 to 14.4°C, respectively. Values for Pit sculpin ranged from 9.9 to 16.4°C at acclimation temperatures of 10, 15 and 20°C. The distributions of marbled and rough sculpin are consistent with their behavioral and metabolic responses to temperature. The widespread distribution of Pit sculpin is consistent with its greater tolerance of high temperatures and eurythermal behavior, but the absence of Pit sculpin from habitats dominated by marbled and rough sculpin is not consistent with a temperature related explanation.     

Thermoregulatory behavior of juvenile cromileptes altivelis (serranidae), a tropical marine fish

Ten juvenile Cromileptes altivelis were tested individually for 3-day periods in electronic shuttleboxes to measure their thermoregulatory behavior. The fish voluntarily occupied a 21–27°C span, out of a potentially available 0–50°C range. The mean final thermal preferendum was 24.5°C for all individuals. The thermoregulatory performance of this species is similar to that of cool temperate freshwater fishes.     

Interspecific variation for thermal dependence of glutathione reductase in sainfoin

Summary Understanding the biochemical and physiological consequences of species variation would expedite improvement in agronomically useful genotypes of sainfoin (Onobrychis spp.) Information on variation among sainfoin species is lacking on thermal dependence of glutathione reductase (B.C. 1.6.4.2.), which plays an important role in the protection of plants from both high and low temperature stresses by preventing harmful oxidation of enzymes and membranes. Our objective was to investigate the interspecific variation for thermal dependency of glutathione reductase in sainfoin. Large variation among species was found for: (i) the minimum apparent Km (0.4–2.5 M NADPH), (ii) the temperature at which the minimum apparent Km was observed (15°–5°C), and (iii) the thermal kinetic windows (2°–30°C width) over a 15°–45°C temperature gradient. In general, tetraploid species had narrower (17°C) thermal kinetic windows than did diploid species (30°C), with one exception among the diploids. Within the tetraploid species, the cultivars of O. viciifolia had a broader thermal kinetic window (7°C) than the plant introduction (PI 212241, >2 °C) itself.This work was supported by USDA Specific Cooperative Agreement No. 58-7MN1-8-143 from the Plant Stress and Water Conservation Unit, USDA-ARS, Lubbock, Texas. Joint contribution of Texas Tech University, Lubbock, Texas and the USDA-ARS. TTU Journal No. T-4-291     

The proteomic response of sea squirts (genus Ciona) to acute heat stress: a global perspective on the thermal stability of proteins

Congeners belonging to the genus Ciona have disparate distributions limited by temperature. Ciona intestinalis is more widespread with a cosmopolitan distribution ranging from tropical to sub-arctic zones, while Ciona savignyi is limited to temperate-latitudes of the northern Pacific Ocean. To compare the heat stress response between congeners, we quantified changes in protein expression using proteomics. Animals were exposed to 22 °C, 25 °C, and 28 °C for 6 h, then recovered at a control temperature (13 °C) for 16 h (high heat stress experiment). In a second experiment we exposed animals to lower levels of heat stress at 18 °C, 20 °C, and 23 °C, with a 16 °C control. A quantitative analysis, using 2D gel electrophoresis and MALDI-TOF/TOF mass spectrometry (with a 69% and 93% identification rate for Ciona intestinalis and Ciona savignyi, respectively), showed changes in a number of protein functional groups, including molecular chaperones, extracellular matrix proteins, calcium-binding proteins, cytoskeletal proteins and proteins involved in energy metabolism. Our results indicate that C. intestinalis maintains higher constitutive levels of molecular chaperones than C. savignyi, suggesting that it is prepared to respond faster to thermal stress. Systematic discrepancies between estimated versus predicted molecular masses of identified proteins differed between protein families and were more pronounced under high heat conditions, suggesting that thermal sensitivities are lower for cytoskeletal proteins and ATP-synthase than for any other protein group represented on 2D gels.     

Behavioral thermoregulation in the spiny lobster Panulirus Argus (latreille)

Ten spiny lobsters (Panulirus argus) were allowed to thermoregulate individually for 3-day periods in an electronic thermoregulatory shuttlebox which allowed them to control water temperatures (and thereby their own body temperatures) by their movements. The range of preferred (voluntarily occupied) temperatures was 25–35°C (mean 29.9°C; mode 30.0°C; median 30.0°C; midpoint 30.0°C; S_k (skewness, Pearson's coefficient) –0.04; s.e.m. 0.19°C; S.D. 2.32°C). The final thermal preferendum (by the gravitation method) in this species is 30°C.     

Lower lethal temperatures for fourteen non-native fishes in Florida

Synopsis The most important factor affecting the potential range of 14 non-native fishes in Florida appears to be their lack of tolerance to low temperatures. In this study, temperatures associated with reduction in feeding, cessation of feeding, loss of equilibrium and death were identified by decreasing water temperature 1°C day^–1. Fishes tested and their mean lower lethal temperatures were: Astronotus ocellatus (12.9°C), Belonesox belizanus (9.7°C), Cichlasoma bimaculatum (8.9°C), C. cyanoguttatum (5.0°C), C. meeki (10.3°C), C. octofasciatum (8.0°C), C. trimaculatum (10.9°C), Clarias batrachus (9.8°C), Hemichromis bimaculatus (9.5°C), Hypostomus sp. (11.2°C), Tilapia aurea (6.2°C), T. mariae (11.2°C), T. melanotheron (10.3°C) and T. mossambica (9.5°C). These data indicate that temperature is less limiting for these fishes in Florida than was previously recognized.Contribution Number 18, Non-Native Fish Research Laboratory, Florida Game and Fresh Water Fish Commmission, 801 N. W. 40th Street, Boca Raton, FL 33431, U.S.A.     

The growth of Epidermophyton floccosum and E. stockdaleae at different temperatures

The ability of 17 strains of genus Epidermophyton (15 strains belonging to Epidermophyton floccosum, one to E. floccosum var. nigricans and one to E. stockdaleae) to grow at different temperatures (4 °C, 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C) was stated.The strains were inoculated on Sabouraud Dextrose Agar and regularly controled over a period of 14 days when the plates were incubated at 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C, and over a period of 70 days when the temperature was 4 °C. The optimal growth of E. floccosum was observed at 28 °C and 31 °C, and no signs of growth were recorded neither at 4 °C nor at 40 °C. The optimal development of E. stockdaleae was observed at 25 °C and 28 °C. This species grew from 4 °C to 31 °C.     

Thermal preference and activity thresholds in populations of Argia vivida (Odonata: Coenagrionidae) from habitats with different thermal regimes

The hypothesis was tested that isolated populations of Argia vivida Hagen living in habitats with different thermal regimes would show similar larval temperature preferenda, similar distributions in a temperature gradient, similar larval upper temperature acitivity thresholds, and similar adult minimum temperature flight thresholds. The hypothesis was supported in all cases, except for distribution within the gradient, where there were significantly fewer observations below 22°C in a population from a habitat with a fluctuating diel and annual temperature regime than in a population from a more thermally stable habitat. Larval modal temperature preferendum was 28°C; escape temperature (EST) was 35.4–36.4°C, critical thermal maximum (CTM) was 39.1–41.0°C, and upper lethal temperature (ULT) was 44.4–46.0°C. While technical difficulties affected the estimates of flight thresholds, there was no difference between the field estimates from different sites. Minimum body temperature for flight appears to be about 25°C, apparently higher than for several other zygopterans, while larval activity thresholds and 96 hr LD50 of 36.8°C are similar to those recorded for other odonates.     

Heterologous expression, refolding and functional characterization of two antifreeze proteins from Fragilariopsis cylindrus (Bacillariophyceae)

Antifreeze proteins (AFPs) provide protection for organisms subjected to the presence of ice crystals. The psychrophilic diatom Fragilariopsis cylindrus which is frequently found in polar sea ice carries a multitude of AFP isoforms. In this study we report the heterologous expression of two antifreeze protein isoforms from F. cylindrus in Escherichia coli. Refolding from inclusion bodies produced proteins functionally active with respect to crystal deformation, recrystallization inhibition and thermal hysteresis. We observed a reduction of activity in the presence of the pelB leader peptide in comparison with the GS-linked SUMO-tag. Activity was positively correlated to protein concentration and buffer salinity. Thermal hysteresis and crystal deformation habit suggest the affiliation of the proteins to the hyperactive group of AFPs. One isoform, carrying a signal peptide for secretion, produced a thermal hysteresis up to 1.53 °C ± 0.53 °C and ice crystals of hexagonal bipyramidal shape. The second isoform, which has a long preceding N-terminal sequence of unknown function, produced thermal hysteresis of up to 2.34 °C ± 0.25 °C. Ice crystals grew in form of a hexagonal column in presence of this protein. The different sequences preceding the ice binding domain point to distinct localizations of the proteins inside or outside the cell. We thus propose that AFPs have different functions in vivo, also reflected in their specific TH capability.     

Thermoregulatory behavior of the triggerfish Balistes fuscus in an electronic shuttlebox

Ten blue triggerfish,Balistes fuscus, were tested individually for 3 days each in Ichthyotron electronic shuttleboxes to measure their thermoregulatory behavior. The modal thermal preferendum, a species-specific measure of temperature preference which is independent of prior thermal acclimation, was 25 °C. The triggerfish voluntarily occupied a 16–27 °C range of temperature, out of a potentially available range of 0–50 °C. There was no significant difference in preferred temperature between night and day, indicating lack of a thermoregulatory rhythm in this species. The preferred temperature range of this tropical marine reef species is similar to that of cool temperate freshwater and marine fishes; many warm temperate species prefer higher temperatures.     

Diel activity and thermoregulatory behavior of a fully aquatic frog: Xenopus laevis

Ten adult Xenopus laevis were tested individually for 48-hr periods, following an initial 24-hr introductory period, in electronic shuttleboxes which allowed them to control water temperatures without operant conditioning. Locomotor activity was recorded via photocell-monitored light beams. The frogs were nocturnal, being nearly twice as active at night as during the day. The mean preferred temperature was 22.4°C, with no significant difference between night (22.5°C) and day (22.3°C), although the modal preferendum shifted from 24°C by day to 22°C at night, with a corresponding change in skewness. The range of voluntarily occupied temperatures was 14–32°C by day and 14–29°C at night. The median thermal preferendum was 22°C both day and night.     

Effect of temperature on vegetative growth among isolates of Metarhizium anisopliae and M. flavoviride

Effects of temperature on vegetative growth on a semi-synthetic medium of 22 isolates of Metarhizium anisopliae and 14 isolates of M. flavoviride were determined. The majority of isolates of both species grew between 11 and 32°C; several isolates grew at 8 and 37 °C. None of the isolates grew at 40 °C. Relative growth rate, calculated from the maximum growth rate for each isolate, was significantly affected by temperature and isolate, with significant isolate * temperature interactions. The maximum absolute growth rates among the isolates ranged from 2.5 mm to 5.9 mm/day. Optimal temperatures were generally between 25 and 32 °C with several isolates exhibiting optimal growth at temperatures as high as 32 °C. Overall, relative growth rates were greater in isolates of M. anisopliae than M. flavoviride at temperatures of 25 °C or lower; conversely mean relative growth rates were greater in M. flavoviride than M. anisopliae at temperatures higher than 25 °C. However, the two most cold tolerant isolates at 8 °C were M. flavoviride and the three most heat tolerant at 35 °C were M. anisopliae. Since temperature growth responses varied considerably between isolates, strain selection according to thermal tolerance may be warranted when choosing a strain for development as a microbial control agent.This revised version was published online in October 2005 with corrections to the Cover Date.     

Galacto-oligosaccharide production by a thermostable recombinant β-galactosidase from <Emphasis Type="Italic">Thermotoga maritima</Emphasis>

Summary A β-galactosidase from Thermotoga maritima produced galacto-oligosaccharides (GOS) from lactose by transgalactosylation when expressed in Escherichia coli. The enzyme activity for GOS production was maximal at pH 6.0 and 90 °C. In thermal stability experiments, the enzyme followed first-order kinetics of pH and thermal inactivation, and half-lives at pH 5.0, pH 8.0, 80 °C, and 95 °C were 27 h, 82 h, 41 h, and 14 min, respectively, suggesting that the enzyme was stable below 80 °C and in the pH range of 5.0–8.0. Mn²⁺ was the most effective divalent cation for GOS production. Cu²⁺ and EDTA inhibited more than 84% of enzyme activity. GOS production increased with increasing lactose concentrations and peaked at 500 g lactose/l. Among tested enzyme concentrations, the highest production of GOS was obtained at 1.5 units enzyme/ml. Under the optimal conditions of pH 6.0, 80 °C, 500 g lactose/l, and 1.5 units enzyme/ml, GOS production was 91 g/l for 300 min, with a GOS productivity of 18.2 g/l · h and a conversion yield of GOS to lactose of 18%.