Behavioural thermoregulation and critical thermal limits of Macrobrachium acanthurus (Wiegman)

• (1)The preferred temperatures of Macrobrachium acanthurus were determined for prawns acclimated to 20°C, 23°C, 26°C, 29°C and 32°C, and the final preferendum estimate was (29.5°C).
• (2)The critical thermal minima (CTMin) and maxima (CTMax) were 11.0°C, 12.1°C, 13.0°C and 14.8°C, and 34.2°C, 35.0°C, 36.1°C and 39.8°C, respectively.
• (3)The zone of thermal tolerance assessed using the CTMin and CTMax boundaries was 644°C².
• (4)The acclimation response ratio was between 0.33 and 0.62.
• (5)To cultivate this species in the southeastern region of México it should be done in not <15°C (CTMin) during the winter and below 38°C in summer (CTMax).

     

Water relations and thermal sensitivity of several cockroach species (Dictyoptera: Blattidae and blaberidae)

• 1.1. Per cent total body water content (%TBW), cuticular permeability (CP), rate of water loss, critical thermal maxima (CTMax), and upper lethal limits (ULL) were determined for Pacific beetle, Diploptera punctata (Eschscholtz), Surinam, Pycnoscelus surinamensis (L.), and Turkestan, Blaita lateralis (Walker), cockroaches.
• 2.2. Initial body mass ranged from 153.16 to 464.96 mg, for D. punctata and P. surinamensis cockroaches, respectively. Mean %TBW was 57.8 for P. surinamensis and 67.7 for B. lateralis.
• 3.3. Mean cuticular permeability was not related to initial mass and ranged from 20.9 to 38.7 μg/cm²/hr/mmHg for D. punctata and P. surinamensis, respectively.
• 4.4. Cumulative mass loss and %TBW lost increased linearly with desiccation time.
• 5.5. CTMax ranged from 43.2°C for D. punctata to 44.3°C for P. surinamensis. There were significant, but small differences in CTMax among the three species.
• 6.6. ULL were 2.2 to approximately 4°C greater than CTMax. The greatest ULL was 48.1°C for B. lateralis and the lowest ULL was 45.0°C for D. punctata.

     

Relations between the growth and the molt interval in the eyestalkless crayfish,Procambarus clarki

• 1.1. An intermittent feed led to an increase in the molt interval but a decrease in the increasing rate of carapace length after each molt in eyestalkless young crayfish. Procambarus clarki.
• 2.2. In the eyestalkless, medium-sized crayfish, the molt interval slightly increased but the increasing rate of carapace length slightly decreased when either 1 or 6 walking legs were removed from their bodies.
• 3.3. The eyestalkless crayfish which were fed sufficiently can grow normally, representing that they have a normal water balance.
• 4.4. In crayfish, the rapid growth itself may be one of the factors for the precocious molt.

     

The activity of glutathione S-transferase in hepatopancreas of Procambarus clarkii: Seasonal variations and the influence of environmental pollutants

• 1.1The glutathione S-transferase activity in hepatopancreas of the American red crayfish Procambarus clarkii after 15 days' acclimatization in tap water aquaria was measured in specimens collected monthly for a whole year, and shows seasonal variation.
• 2.2. Previous data on the environmental pollution of Lake Albufera suggest a possible correlation with the activity tested in the different seasons of the year considering the results of non-acclimatized animals.

     

Respiratory responses of excised gills of the stout razor clam,Tagelus plebeius solander,to acute temperature changes throughout the year

• 1.1. The exponent (b) relating metabolic rate to dry weight in excised gills of Tagelus plebeius is not maintained constant throughout the seasons or upon acute exposure to temperatures of 9–34°C.
• 2.2. Acclimation (11–29°C) and test (9–34°C) temperatures have a significant effect (α = 0.01) on the mean rate of oxygen uptake by the gills.
• 3.3. Positive seasonal thermal acclimation is observed up to acclimation temperatures of 19.5–20°C, which is also the temperature of minimum respiratory response to all acute test temperatures.
• 4.4. Regions of thermal metabolic insensitivity are seen over small acute temperature ranges near the acclimation temperatures.

     

Correlation between motor and electroretinographic circadian rhythms in the crayfish Procambarus bouvieri (ortmann)

• 1.1. The characteristics of both, motor and electroretinographic circadian rhythms in the crayfish Procambarus bouvieri, were examined.
• 2.2. The correlation between both rhythms in intact and brainless crayfish, was obtained.
• 3.3. The presence of at least two different but coupled oscillators responsible for the circadian variations in crayfish, is proposed.

     

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.

     

Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

Differential weighting of electrophoretic data in crayfish and fiddler crabs (decapoda: astacidae and ocypopidae)

• 1.1. Muscle proteins from the chelae of six crayfish species and ten species of Uca were compared through disc electrophoresis (split gel technique).
• 2.2. No intraspecies variation of the electrophoretic pattern was found.
• 3.3. In interspecies comparisons all components (bands) were weighted individually and specified as ancestral or derived characters.
• 4.4. In the crayfishes the phylogenetic trees constructed from electrophoretic and classical data were found to be congruent. In Uca some branches of either tree remained undefined. Each tree, however, helped complete the other one.

     

Seasonal variation in the energy metabolism in an estuarine crab,Chasmagnathus granulata (Dana, 1851)

• 1.1. The effects of seasonal variation on the carbohydrate and lipid metabolism of the Chasmagnathus granulata were investigated.
• 2.2. Glycemia is high in winter and summer and low in spring and fall.
• 3.3. The glycogen content in the hepatopancreas and muscle is higher in fall and winter, and decreases during spring and summer.
• 4.4. The muscle lipids are higher in summer, and decrease during fall and winter whereas hepatopancreas lipids are higher except in the fall.
• 5.5. The crabs show change in the metabolic pattern of lipids and carbohydrates during the seasons of the year.

     

Mitochondrial malic enzyme from the crayfish abdomen muscle,purification, regulatory properties and possible physiological role

• 1.1. Mitochondrial malic enzyme (l-Malate: NADP oxidoreductase (oxaloacetate decarboxylating) EC 1.1.1.40) has been isolated from abdomen muscle of crayfish Orconectes limosus by chromatography on Sepharose 6B and DEAE cellulose. Specific activity of the purified enzyme was about 5 μmols per min per mg protein, which corresponds to about 30-fold purification.
• 2.2. This enzyme showed extremely small reversiblity, since the reaction in the direction of decarboxylation is at least 37, 190 and 760 times that for the carboxylation at pH 7.0, 7.5 and 8.0 respectively.
• 3.3. Purified enzyme showed allosteric properties, which was more accentuated at more alkaline pH (Hill coefficients were 1.1, 1.7 and 1.8 at pH 7.0, 7.5 and 8.0 respectively). The activity of malic enzyme was increased considerably in the presence of succinate and fumarate.
• 4.4. Mitochondira isolated from abdomen muscle of Orconectes limosus incubated in the presence of malate, fumate and succinate catalysed pyruvate production which was stimulated by ADP and inhibited by respiratory chain inhibitors.
• 5.5. NADH but not NADPH oxidation was catalysed by broken mitochondria or sonic particles. When NADPH and NAD were added simultaneously the rate of oxidation. This suggests the presence of active NADPH:NAD transhydrogenase in mitochondria isolated from the crayfish abdomen muscle.
• 6.6. A possible metabolic role for NADP-linked malic enzyme/transhydrogenase couple in abdomen muscle of crayfish Orconectes limosus is proposed.

     

Environmental and genetic influences on the thermal physiology of Rana sylvatica

• 1.1.|Intraspecific variation in the thermal physiology of Rana sylvatica was examined.
• 2.2.|Heat and cold tolerances of both adult and larval representatives were determined for animals representing populations from New York, Maryland, Kentucky, Ohio, Michigan and Canada.
• 3.3.|In general, frogs from more northern localities exhibited lower heat tolerances.
• 4.4.|There was no evidence of interpopulational differences in cold tolerance. Similar trends were revealed by larval testing.
• 5.5.|Interpopulational differences among laboratory-reared tadpoles suggests a strong genetic component to Rana sylvatica thermal physiology.

     

Variation of l-gulonolactone oxidase activity in placental mammals

• 1.1. The activity of l-gulonolactone oxidase (EC 1.1.3.8) in livers of 49 species of eutherian mammals varied intraspecifically among individuals; coefficients of variation were 0.2 to 0.4 in many species.
• 2.2. Differences observed in l-gulonolactone oxidase activity among strains of laboratory rats and domestic rabbits are probably genetically controlled.
• 3.3. Pronounced sex differences in l-gulonolactone oxidase activity were found in some species, particularly in the genera Peromyscus, Reithrodontomys and Onychomys.
• 4.4. Mormota monax exhibited seasonal variation in l-gulonolactone oxidase somewhat like that previously observed in Sylvilagus floridanus; no such seasonal variation was found in Sciurus carolinensis.
• 5.5. Hibernation did not affect l-gulonolactone oxidase activity in Spermophilus tridecemlineatus.
• 6.6. In four species of rodents, Microtus ochrogaster, Tylomys panamensis, Octodon degus and Sigmodon hispidus, l-gulonolactone oxidase activity was not affected by the level of dietary ascorbate.

     

Geographical variation of heat sensitivity and water loss rates in the tropical lizard,Anolis gundlachi

• 1.1. Sensitivity to high temperatures and desiccating conditions were separately measured in four samples of Anolis gundlachi collected over an altitudinal transect and one sample of lowland A. cristatellus.
• 2.2. Critical thermal maxima (CTM) of gundlachi samples varied inversely in perfect rank order with elevation from a low of 33°C at 850m to a high of 36°C at 270m. The data suggest a possible genetic basis of the variation. No other measures of heat sensitivity exhibited significant altitudinal variation in gundlachi.
• 3.3. Rates of evaporative water loss among gundlachi samples exhibited the same pattern of population differentiation as did the CTMs. Survival times also varied among samples, but vital limits of desiccation did not.
• 4.4. A. cristatellus was invariably more heat and desiccation resistant than its montane counterpart, A. gundlachi.

     

Yolk synthesis in the marine shrimp,Penaeus vannamei

• 1.1. In vitro yolk synthesis was measured in fragments of the ovary of developing shrimp, Penaeus vannamei.
• 2.2. Progesterone and estradiol stimulated yolk synthesis in vitro, while ecdysterone, testosterone and estrogen had no effect.
• 3.3. A peptide factor from the eyestalks of crayfish stimulated yolk synthesis in vitro. A peptide factor from shrimp eyestalks inhibited yolk synthesis in vitro.

     

Heart rate and its cholinergic control in the sole (Solea vulgaris), acclimatized to different temperatures

• 1.1. The effects of thermal acclimatization at 10 and 24°C on heart rate were investigated on unrestrained soles (Solea vulgaris).
• 2.2. The sensitivity of heart rate to temperature changes induced by temperature acclimatization was higher in cold-acclimatized than in warm-acclimatized soles.
• 3.3. Heart rate of cold-acclimatized fish to temperature changes was not affected by blocking the vagal tone with atropine.
• 4.4. After atropine treatment the ability of heart rate to show thermal compensation decreased in warm-acclimatized soles.
• 5.5. It is suggested that the vagus nerve can function differently at different temperatures.

     

A novel inhibitor of glycogen phosphorylase from crayfish hepatopancreas

• 1.1. A novel glycogen phosphorylase inhibitor was partially purified from crayfish hepatopancreas.
• 2.2. The inhibitor was found only in two species of crayfish examined, and not in lobster, fresh and salt water clams, mussels or cockroaches.
• 3.3. The inhibitor is a small protein (M_r = 23,000) which did not show proteolytic activity.
• 4.4. Preliminary kinetic analysis of the inhibitory mechanism indicated that it bound to both glycogen and the glycogen phosphorylase protein.
• 5.5. Inhibitor binding to glycogen resulted in a competitive inhibition pattern with respect to glycogen phosphorylase (inhibition constant of ca 10 μg/ml).
• 6.6. The inhibitor also bound glycogen phosphorylase directly with a binding coefficient of 100 μg/ml resulting in a partially non-competitive inhibition pattern with respect to phosphate.

     

Phosphorylation in crayfish (Procambarus clarkii) eggs during hatching

• 1.1.|The high-energy phosphorylation metabolism in crayfish, Procambarus clarkii eggs during brooding and juvenile crayfish after hatching was studied by in vivo³¹P nuclear magnetic resonance (³¹P NMR) spectroscopy.
• 2.2.|Inorganic phosphoric acid (Pi) and adenosine-5′-triphosphate ATP(γ-,α-,β-) were detected in the dark brownish red eggs after oviposition.
• 3.3.|In orange unhatched eggs, only sugar phosphate (SP), Pi and resolved phosphometabolite from ATP were observed.
• 4.4.|Peaks of SP, Pi, arginine phosphate (Arg-P), and ATP (γ,α,β) appeared in larvae of crayfish after hatching (nauplius, zoea and juvenile crayfish).
• 5.5.|The high-energy phosphorylation metabolism changed to an anaerobic condition along with a decrease in the concentration of dissolved oxygen in fresh water.

     

Seasonal variation of LH and testosterone in the smallest deer,the pudu (Pudu puda molina) and its relationship to the antler cycle

• 1.1. In order to obtain a seasonal profile of LH, three adult male pudu (Pudu puda, Molina) were sampled monthly from the saphenous vein for a period of one year.
• 2.2. A significant circannual variation of plasma LH levels was detected with an average peak value (1.77 ng/ml) recorded in February and nadir concentrations (0.19 ng/ml) observed in November.
• 3.3. The peak level of testosterone (1.54 ng/ml) was detected in March, the time of the rut.

     

Effects of feeding on water balance and cutaneous drinking in the toad (Bufo bufo L.)

• 1.1. Toads fed mealworms ad libitum for 24-hr periods once a week retained water in the body in amounts that varied with meal size, as well as temporally.
• 2.2. The ratio between masses of water retained and mealworms eaten increased from about 0.5 in May to about 1.3 by mid-July, and declined again at the end of the seasonal feeding period. li[3. It is argued that this pattern reflects seasonal variation in the secretion of digestive (gastric) juice in response to meal size.
• 3.4. The cutaneous drinking response, reflected in number of visits to the water source, increased in strength with successive feedings.
• 4.5. It is suggested that the drinking response to feeding included a secondary, behavioural component, superimposed upon a primary response to feeding.