Effects of acclimation temperature,season, and time of day on the critical thermal maxima and minima of the crayfish Orconectes rusticus

• 1.1. The critical thermal minima (CTMin) and maxima (CTMax) were determined for field-acclimatized and laboratory-acclimated crayfish (Orconectes rusticus) throughout 1984.
• 2.2. The CTMin and CTMax of field-acclimatized crayfish were seasonally adjusted by 9.7 C and 14.7 C respectively.
• 3.3. Seasonal variation in both tolerance regimes persisted in crayfish acclimated in the laboratory at 5 and 25°C for one week; however, no diel variation existed in either the CTMin or CTMax of laboratory-acclimated crayfish.
• 4.4. Integration of thermal acclimation of the CTMin and CTMax with seasonal conditioning may influence the functional capacities of this species when considered in relation to the seasonal ranges in stream temperature.

     

Cardiac frequency compensation responses of adult blue crabs (Callinectes sapidus Rathbun) exposed to moderate temperature increases

• 1.1. Cardiac frequency patterns of Callincctes sapidus Rathbun were used to evaluate potential thermal stress after exposure to 5°C increases over a range of acclimation temperatures from 5° to 30°C.
• 2.2. An acclimated rate-temperature curve (R-T curve), acute R-T curves of the stabilized rates at the increased temperatures and Q₁₀ temperature coefficients were used to assess the significance of the changes in rate frequency.
• 3.3. The acclimated R-T curve showed that blue crabs go through a series of seasonal adaptation types characterized by a plateau of perfect adaptation for both cold and warm adapted organisms. Paradoxical adaptation occurred between the transition from cold to warm acclimation temperatures.
• 4.4. The acute R-T curves showed that cardiac frequency was highly responsive to a 5°C increase when the organisms were acclimated to low temperatures.
• 5.5. The Q₁₀'s of the acute R-T curves at the warm acclimation temperatures approximated those values derived for the acclimated R-T curve.
• 6.6. This suggests that the temperature increase had a negligible effect on the warm adapted crabs, that is, little or no thermal stress occurred.

     

Adaptative features of amazon fishes: Hemoglobins,hematology, intraerythrocytic phosphates and whole blood Bohr effect of Pterygoplichthys multiradiatus (Siluriformes)

• 1.1. Hemoglobin, hematological parameters, intraerythrocytic phosphates and whole blood Bohr effect of Pterygoplichthys multiradiatus, from the Amazon river, were studied in three different conditions: in their natural environment, acclimated to normoxia and acclimated hypoxia conditions.
• 2.2. Nine anodal hemoglobin fractions were detected on starch gel electrophoresis. No qualitative differences in the Hb electrophoretic patterns were detected in the three studied groups.
• 3.3. Hematocrit, hemoglobin concentration, MCV, MCHC and MCH were different among studied conditions.
• 4.4. GTP was almost absent in the blood of animals in natural conditions and acclimated to hypoxia, but was present at a concentration similar to ATP in normoxic acclimated animals.
• 5.5. There is a tendency for higher Hb-O₂ affinity for hypoxic acclimated/acclimatized animals.

     

The dependence of oxygen consumption of the common whelk (Buccinum undatum) on hypoxia,salinity and air exposure

• 1.1. Oxygen consumption of low salinity (20‰) acclimated whelks decreases markedly upon acute exposure to hypoxia (P_WO₂ = 35 Torr), but almost regenerates its original level within 48 hr exposure to the hypoxic condition.
• 2.2. This ability to regain the original level of oxygen consumption is not seen in high salinity (35‰) acclimated whelks.
• 3.3. Oxygen consumption in air at 10°C is more than twice the rate shown by low salinity acclimated whelks in normoxic water (P_WO₂ = 150 Torr).
• 4.4. Q₁₀ for oxygen consumption in air is about 1.0 in the temperature range 10–20°C.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Relationship of growth to SDA

• 1.1. The relationship of Specific Dynamic Action (SDA) to growth was examined in the supralittoral isopod Ligia pallasii using a seaweed diet fed at different rations.
• 2.2. Animals increased in live weight by 33% on an ad libitum or 100% diet and by 2% on a 20% ration over a 10-week period.
• 3.3. Weight-specific VO₂ was significantly higher in animals eating the 100% diet than in ones eating the 20% diet. Decline in VO₂ with time in animals on the 20% diet was probably due to poor health associated with a maintenance ration.
• 4.4. SDA per unit weight of food eaten was 18% higher in the 20% diet group than in the 100% one, and values remained constant over time in both groups.
• 5.5. k₁ growth efficiencies (production/consumption) were higher in animals on 100% ration than in ones on 20% ration. Efficiencies declined with time in both diet-groups and fell below zero in the 20% ration-group, coincidental with weight-loss in some of the animals.
• 6.6. Overall SDAs for the 10-week period were positively correlated with growth (r₂ = 0.77), but there was no way to separate this from amounts eaten as an effect on SDA.

     

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.

     

Aerobic and anaerobic respiration of adult Artemia salina L., acclimated to different oxygen concentrations

• 1.1. Adult male Atremia salina L. were acclimated to five different oxygen concentrations and their respiration in response to environmental oxygen concentrations was determined.
• 2.2. Anemia is a respiratory regulator over a wide range of partial O₂ pressures. A critical oxygen tension exists and decreases with acclimation to lower pO₂.
• 3.3. Hypoxic conditions induce the production of hemoglobin III.
• 4.4. Lactic acid is produced during anaerobiosis.
• 5.5. Production of Hb III and lactic acid, being inversely proportional to the acclimation level, has to be considered as a long term or short term adaptation to hypoxic conditions.

     

Modification of glyceraldehyde-3-phosphate dehydrogenase,EC 1.2.1.12, isolated from rainbow trout during acclimation at 5 or 15°C—II. Biochemical characterization of G3PDH muscle isolates

• 1.1. G3PDH was isolated from the lateral muscle of rainbow trout (Salmo gairdneri) acclimated at 5°C (cold) and 15°C (warm).
• 2.2. No differences were found in muscle concentration, molecular weights, isoelectric focusing patterns, amino acid compositions or peptide maps between cold and warm isolates.
• 3.3. Cold and warm G3PDH contained mannose in variable concentration but no other prosthetic groups.

     

Metabolic rates of Calathus melanocephalus (L.) (coleoptera,carabidae) from alpine and lowland habitats (jeløy and finse,norway and drenthe,the netherlands)

• 1.1. Metabolic rates (ml O₂/mg/hr) of three geographically separated populations of the carabid beetle Calathus melanocephalus L. (Finse and Je 10y, Norway and Drenthe, The Netherlands) were measured and compared by ANCOVA.
• 2.2. No significant relationship (P > 0.05) between metabolic rates and body weight or sex of the animals were found.
• 3.3. Individuals mostly acclimated to low temperatures by increased metabolic rates and in the opposite direction to higher temperatures. Individuals collected in early summer also showed higher metabolic rates than those caught later in the autumn.
• 4.4. Contradicting the theory of metabolic cold adaptation, beetles from The Netherlands had the highest metabolic rates, beetles from Finse intermediate rates and beetles from Jeløy the lowest rates.
• 5.5. No significant relation were found between geographical origin of the beetles and their respective chill-coma temperature.

     

Cyclic AMP stimulation and prostaglandin inhibition of Na transport in freshwater mussels

• 1.1. Pondwater acclimated Carunculina texasensis and Ligumia subrostrata experienced a 230% increase in Na influx when injected with dibutyryl cyclic AMP (0.4mM/l blood).
• 2.2. Theophylline, a phosphodiesterase inhibitor, or indomethacin, an inhibitor of prostaglandin (PG) synthetase, caused a dose dependent stimulation of Na transport.
• 3.3. Prostaglandin E₂ injected into mussels caused an inhibition of Na influx. Arachidonic acid, the precursor of PGE₂, inhibited Na influx or stimulated Na efflux depending on the animal's acclimation conditions.
• 4.4. Chloride transport was unaffected by the drugs used in this study.

     

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.

     

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.

     

Temperature shift-induced changes in the antioxidant enzyme system of Cyanobacterium synechocystis PCC 6803

• 1.1. Effect of controlled up- and down-shifts of growth temperature on the antioxidant enzymes activities and lipid peroxidation were investigated in intact cells of Cyanobacterium synechocystis PCC 6803 acclimated at different growth temperature.
• 2.2. Algal cells grown at 36°C were treated at 20 and 43°C as down- and upward-shifts of growth temperature for 24 hr, respectively. At the down-shift of growth temperature the superoxide dismutase, catalase and glutathione peroxidase were significantly increased with concomitant decrease in protein content.
• 3.3. These parameters showed similar temperature dependencies in the up-shift of growth temperature, they were decreased significantly.
• 4.4. The increased hydroxyl (HO) radical and malonyldialdehyde (MDA) formation, when algal cells exposed to down-shift of growth temperature, supposedly due to stimulated production of superoxide radicals (O₂⁻) and hydrogen peroxide (H₂O₂) at lower temperature.

     

Anuran amphibia which are not acclimable to high salt,tolerate high plasma urea

• 1.1. The capacity of five anuran Amphibians (Bufo viridis B. regularis, Rana ridibunda, Hyla arborea and Pelobates syriacus) to acclimate to NaCl and urea solutions was investigated.
• 2.2. All species could be acclimated to relatively high concentrations of urea solutions, while only Bufo viridis and Hyla arborea could be acclimated to 500 mOsm/kg or higher NaCl solutions.
• 3.3. The plasma urea concentration in B. viridis and H. arborea was elevated to levels over 140 mmol/1.
• 4.4. The sum of plasma sodium and chloride concentrations did not increase over 400 mmol/l in any species.
• 5.5. Urine osmolality, which was normally low, increased, but never exceeded the plasma osmolality.
• 6.6. In the urea acclimation conditions, urine electrolytes diminished, similarly in all species in this study.
• 7.7. It is concluded that anuran Amphibians can tolerate high plasma urea concentrations, but only those species which can elevate it, either through retention or net synthesis, can be acclimated to high salt solutions.

     

Aerial respiration in the semaphore crab,Heloecius cordiformis,with or without branchial water

• 1.1. Semaphore crabs (Heloecius cordiformis) are active in air at low tide. Their branchial chambers are lined with a vascular epithelium and are expanded above the gills (five pairs) to form air cavities which could function as lungs. Water is continuously circulated over the gills.
• 2.2. The relative contribution made by the gills and lungs to gas exchange in semaphore crabs active in air and circulating branchial water, was determined by measuring oxygen consumption (at 25°C) in crabs with and without branchial water, and in crabs with their lungs subsequently occluded.
• 3.3. Activity levels and VO₂ were unaffected by the absence of branchial water.
• 4.4. With their lungs occluded, VO₂ dropped (on average) by 61% in crabs with branchial water (i.e. gills still functional) and by 81% in crabs without branchial water (gill function impaired).
• 5.5. It is concluded that semaphore crabs are obligate air breathers while active on land, despite carrying water within their branchial chambers. Lung development and gill reduction in land crabs is discussed briefly in relation to “terrestriality”.

     

Biomines-stimulated phosphorylation and (Na+, K+-ATPase in the gills of the chinese crab,Eriocheir sinensis

• 1.1. Subcellular distribution of (NA⁺, K⁺-ATPase and ouabain-insensitive ATPase (Mg²⁺-ATPase) are compared in branchial tissues of the euryhaline crab, Eriocheir sinensis, acclimated to fresh water.
• 2.2. Both the anterior and posterior gills contain cAMP-dependent protein kinase and endogenous protein substrate for phosphorylation.
• 3.3. Phosphorylation occurs in both “particulate” and “soluble” subcellular fractions but its stimulation by cAMP is restricted to the “soluble” fraction.
• 4.4. serotonin (5-HT) and dopamine receptors are present only in the “light particulate” fraction isolated from the posterior gills.

• 1.(a) Serotonin and dopamine have no effect on the phosphorylation observed in a subcellular fraction alone.
• 2.(b) Activation of the phosphorylation by serotonin and dopamine is found when the soluble fraction (source of cAMP-dependent protein kinase) is added to the fraction P₃ from the posterior gills.
• 3.(c) No activation occurs with the fractions P₃ as well as P₁ or P₂ (not shown) from anterior gills of fresh water crab.
• 4.(d) Cyproheptadine, a serotonin receptor antagonist, inhibits the 5-HT dependent increase in phosphorylation.
• 5.(e) The dopamine receptor antagonist, chlorpromazine, inhibits dopamine-stimulated phosphorylation.
• 6.5. Ouabain mimics the effect of cyproheptadine on the serotonin-stimulated phosphorylation found in the posterior gills.

     

The influences of individual variations in metabolic rate and tidal conditions on the response to hypoxia in Carcinus maenas (L.)

• 1.1. The oxygen consumption of crabs in normoxic and hypoxic (50% O₂) seawater was measured directly after collection.
• 2.2. The influences of size and lunar cycles were removed by scaling the data.
• 3.3. Strong negative correlations between low individual levels of O₂ consumption and the ability to compensate for hypoxia were apparent in Wicklow (subtidal) crabs.
• 4.4. Compensation for hypoxia was much greater on the flood tide than on the ebb.
• 5.5. Crabs from Roscoff (intertidal) had lower levels of compensation than those from Wicklow.
• 6.6. Size, sex and condition had no apparent effect upon these relationships.
• 7.7. Crabs acclimated to laboratory conditions have not shown this tidal variation in compensation for hypoxia.

     

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.

     

The effects of temperature on oxygen consumption in Bullia digitalis meuschen (Gastropoda,Nassaridae)

• 1.1. The oxygen consumption of Bullia digitalis from South Africa's west coast, measured at a fixed activity level at 15°C, does not differ significantly between winter and summer.
• 2.2. The adult acute rate-temperature curve is flattened over the temperature range likely to be encountered in the field, there being no significant difference in oxygen consumption between 15 and 22.5°C.
• 3.3. Below this plateau the Q₁₀ is normal, giving a value of 2.67 between 5 and 10°C, but at temperatures above 22.5°C the Q₁₀ is less than 2 and oxygen consumption at 30°C does not approach that of the tropical Bullia melanoides at the same temperature.
• 4.4. Both field and laboratory acclimated animals provide evidence that the rate-temperature curve is unaffected by such acclimation, either to high or low temperatures.

     

A study of visual pigments in the two antarctic crustaceans Orchomene plebs (Amphipoda) and Glyptonotus antarcticus (Isopoda)

• 1.1. Total chromophore contents as well as the contributions made by 11-cis retinal were determined by high pressure liquid chromatography in light- and dark-adapted eyes of Orchomene plebs and Glyptonotus antarcticus (Amphipoda and Isopoda, respectively).
• 2.2. In O. plebs the highest amount of total chromophore in pmol/eye was found to be 18.5 in 36 hr dark-adapted animals. The lowest amount (11.6 pmol/eye) was recorded in 24 hr light-adapted individuals.
• 3.3. In dark-adapted O. plebs, irrespective of whether dark-adapted for 36 or 60 hr, the percentage of 11-cis retinal was maximally 96.6%. In the light-adapted material it reached 71.2%
• 4.4. In eyes of 20 hr dark-adapted Glyptonotous antarcticus, possibly because of insufficient dark adaptation, a total chromophore content of only 3.2 pmol/eye was found. The percentage of 11-cis retinal was 55.8.
• 5.5. Porphyropsin with its testable 3-dehydroretinal (vitamin A₂-aldehyde) was not encountered in any of our samples.
• 6.6. Calculations of photopigment per gram body weight and a comparison with data from freshwater crayfish show that dark-adapted O. plebs possess approximately 20 times the relative photopigment amount of the crayfish. Absolute sensitivity of the eye of O. plebs is, therefore, expected to be very high.