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.

     

Ultradian oscillation in the heart rate of rainbow trout (Oncorhynchus mykiss)

• 1.1. Ultradian oscillations in the min and hr range on long-term (24-hr) computerized recordings of heart rate in rainbow trout Oncorhynchus mykiss, acclimated to 5, 10 and 15°C water temperature, were investigated. Eight-hour duration time series derived from the heart rate recordings were analysed for their harmonic content in the ultradian band by spectral analysis.
• 2.2. A significant ultradian rhythm at around 0.011 cycles/min (approximately 91-min period) was detected in the power spectral density functions of all the 8-hr duration time series derived from the heart rate recordings at the three experimental water temperatures.
• 3.3. The spectral power of the ultradian oscillation detected in heart rate of trout was found to increase significantly with increasing temperature.
• 4.4. The possible endogenous origin of the ultradian rhythm detected in heart rate of Oncorhynchus mykiss is discussed.

     

The role of growth,predation, and habitat selection in the population distribution of the crown conch,Melongena corona Gmelin

The intertidal gastropod Melongena corona Gmelin exhibits a size gradient along the shore as a function of habitat. Small, juvenile snails were found on the sand beach and larger adults were found on hard substratum habitats (shell rubble beach and oyster bar). A transplant experiment was performed to test three proximate explanations for this pattern:

• 1.(1) differential growth rate of conchs in different habitats,
• 2.(2) differences in predation intensity between habitats and
• 3.(3) active habitat selection by snails.

Shell scars on the last shell whorl were used as an index of predation pressure. Growth and predation were not significantly different for snails of similar size in different habitats, but snails were found to return to their original habitat when displaced. The ability to home did not differ between sexes or juveniles and adults. Active habitat selection appears to be a significant proximate factor maintaining the population distribution. A number of potential ultimate causes of the size class segregation are suggested.     

Breast,hips, and buttocks revisited: Honest fatness for honest fitness

This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:

• 1.1. Sexual selection has probably not been the most important selection pressure on
• 2.female human body shape.
• 3.2. Male humans in different cultures find different aspects of the female body attractive
• 4.and therefore are unlikely to have exerted consistent directional sexual selection on
• 5.the female body.
• 6.3. Breast size is not correlated with lactation success.
• 7.4. Visible hip width is not correlated with parturition success.
• 8.5. Women would lower their fitness if they tried to deceive men about their internal
• 9.pelvic dimensions.
• 10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
• 11.breast, hips, and buttocks.

     

Osmotic changes in an estuarine bivalve,Modiolus fluviatilis

• 1.1.Responses to different salinities monitored by opening and closing of the shell valves were observed in Modiolus fluviatilis.
• 2.2.The osmotic pressure, sodium and chloride ion concentrations were measured in the haemocoelic fluid of Modiolus fluviatilis under similar conditions.
• 3.3.Free amino acids (measured as ninhydrin-positive substances) were determined in the muscle tissue of Modiolus.
• 4.4.It appears that these free amino acids are involved in the ability of the estuarine bivalve Modiolus fluviatilis to osmoregulate in a wide range of salinities.

     

The influence of optic nerve section on blood metabolite levels in Carcinus maenas (Crustacea: Brachyura)

• 1.1. Blood metabolite levels were assayed in Carcinus maenas as an indicator of the functioning of the hyperglycemic hormone, HGH, secreted by the crab's eyestalk neuroendocrine tissue.
• 2.2. Bilateral eyestalk ablation eventually resulted in a hypoglycemic response after 2–3 days.
• 3.3. Bilateral optic nerve section produced a significant, long-term hypoglycemic response suggesting that release of HGH from the eyestalk sinus gland is controlled, via a promotive neural pathway, by the CNS and probably by the cerebral ganglia.
• 4.4. Injection of eyestalk extract into operated crabs consistently produced significant, short-term hyperglycemia.

     

Influence of temperature,rate of feeding and body weight on nitrogen metabolism of bream,Abramis brama L

• 1.1. Measurements of the rate of nitrogen consumption, total nitrogen and ammonia excretion and nitrogen absorption of bream, Abramis brama L. (body weight range 0.4–519 g wet wt) were made at 10, 15 and 20 C.
• 2.2. Fish were fed once daily on live zooplankton collected in Lake Balaton and cultured Tubifex sp. at 5–15% of their body weight.
• 3.3. Fish size and temperature had a combined effect on the rate of total nitrogen excretion. Total nitrogen excretion did not increase proportionally with an increase in consumption.
• 4.4. On average, 52–80% of the nitrogen consumed with food was excreted by bream.
• 5.5. The greatest part of total nitrogen excretion was ammonia and its proportion in the total ranged between 53 and 75%.
• 6.6. Temperature did not have any significant effect on the proportion of excreted ammonia and the rate of excreted total nitrogen was the only factor determining its proportion in the total.
• 7.7. The rate of nitrogen absorption of bream was surprisingly very high.

     

Temperature acclimation in respiratory and cytochrome c oxidase activity in common carp (Cyprinus carpio)

• 1.1. Common carp (Cyprinus carpio) exposed to experimental temperatures of 12, 18, 24, 30 or 36°C for a 4-week period were used to investigate the effect of temperature acclimation on the frequency of opercular movement (FOM), growth and cytochrome c oxidase (CCO) activity in heart, liver and muscle.
• 2.2. An exponential relationship between FOM and temperature after the first week (10₁₀ =1.76) disappeared after the second week.
• 3.3. The initially high FOM at temperatures of 30 or 36°C and the low FOM at 18 or 12°C changed over 4 weeks to approach the FOM of fish at 24°C.
• 4.4. This change in the relationship of FOM to temperature from highly dependent to independent appeared to be thermal compensation.
• 5.5. Heart and liver CCO activities were significantly affected by temperature, with the lowest activity at the approximate optimum temperature for growth, 24°C.
• 6.6. Highest CCO activities for heart and liver occurred at both the highest and lowest temperatures.
• 7.7. Among the three tissues, heart CCO activity was generally the highest and most affected by acclimation temperature.
• 8.8. Muscle tissue had the lowest CCO activity and was unaffected by temperature.
• 9.9. The high CCO activity at a cold acclimation of temperature 12°C was probably due to thermal compensation and the high activity at 36°C may have been a result of thermal stress.

     

Sodium balance in adult atlantic salmon (Salmo salar L.) during migration into neutral and acid fresh water

• 1.1. In sea-water, adult salmon (S. salar) exchange an average of 12.6% of total body sodium/hr.
• 2.2. Following transfer to fresh water sodium uptake follows Michaelis-Menton kinetics. F_max = 2.40 mmol Na/1 ECF/hr, K_m = 0.26 mmol Na/1. The uptake system is fully activated immediately following transfer to fresh water.
• 3.3. Post smolts adapted to sea-water for 3 months take up sodium at only one third of the rate of adult fish following return to fresh water.
• 4.4. The concentration of prolactin in the plasma is low in sea-water adapted fish and does not rise during the first 8 hr in fresh water.
• 5.5. At pH 5 sodium uptake is reduced by almost 90%, even in the absence of aluminium, but recovers immediately on return to neutral water.
• 6.6. At pH 5 and 20 μmol Al/1 there is little further effect on sodium uptake but after 6 hr in aluminium the inhibition of sodium uptake continues after return to neutral aluminium fresh water and uptake is only 50% of normal 24 hr later.

     

Measurements of oxygen consumption in Mytilus edulis during exposure to,and recovery from,high sublethal concentrations of formaldehyde,benzene and phenol

• 1.1. The rate of oxygen consumption has been monitored continuously in M. edulis during acute exposure to high sublethal concentrations of formaldehyde, phenol and benzene and subsequent recovery periods of 96 hr.
• 2.2. The results are discussed in relation to changes in the electrochemical potential difference of sodium, the content of ATP and the tissue concentration of strombine.
• 3.3. After exposure to benzene and phenol, an increase in the rate of oxygen consumption that could not be explained by oxygen debt from the exposure period was observed.
• 4.4. Depression of the rate of oxygen consumption after exposure to formaldehyde may be explained by a reduced ability to extract oxygen from the water.
• 5.5. The pattern of oxygen consumption and behavioural responses, as well as the combined changes in the biochemical markers, were distinctly different in the three cases.

     

Sex-specific gene expression in distinct tissues of the shrimp Penaeus vannamei

• 1.1. Soluble proteins extracted from male and female Penaeus vannamei tissues such as eyes, eyestalks, brain, nerve cord, hemolymph, heart, muscle, hepatopancreas, hepatopancreas membrane and cuticular epidermis were analyzed and compared by high-resolution mini-two-dimensional polyacrylamide gel electrophoresis (mini-2D-PAGE).
• 2.2. In each shrimp tissue a large number of discrete polypeptides was observed.
• 3.3. The polypeptide patterns from the same tissue of female and male shrimp were mostly similar but both qualitative and quantitative differences were noted, suggesting the presence of sex-specific gene products in various shrimp tissues.
• 4.4. Future applications of these results are discussed.

     

A relationship between circulating natural glucocorticoids and the mechanical responses of the heart in atricial and precocial rodents

• 1.1. A comparison was made of the mechanical performance of heart muscle from mouse, an atricial mammal, with corticosterone as glucocorticoid and spiny mouse (Acomys cahirinus), a precocial mammal, with cortisol as glucocorticoid.
• 2.2. Force-frequency responses were negative in mouse and positive in spiny mouse.
• 3.3. During recovery, there was a gradual increase and an overshoot in the mouse, while in the spiny mouse there was an initial enhanced response, diminishing gradually with time.
• 4.4. High calcium concentration inhibited contractile tension in mouse heart, while it was positively inotropic in spiny mouse heart. Changes in the concentration of calcium did not change the patterns of force-frequency response.
• 5.5. Lowering the experimental temperature increased the time course and amplitude of the tension curve. However, various parameters exhibited different temperature sensitivity.
• 6.6. There was a significant difference in the levels of circulating cortisol between male and female spiny mice.
• 7.7. It is proposed that the differences in the mechanical responses of mouse and spiny mouse hearts may be explained in terms of the effects of the specific glucocorticoid hormone on the development of the sodium-calcium exchanger.

     

Subcellular distribution of metals within the kidney of the bivalve Mercenaria mercenaria (L.)

• 1.1. The subcellular distribution of nine transition metals (plus four additional elements) was measured in the kidney tissue of the quahog, Mercenaria mercenaria.
• 2.2. Elemental analyses of the subcellular fractions indicated three main patterns of metal distribution within kidney cells.
• 3.3. Barium, iron, manganese and lead were associated primarily with kidney granules.
• 4.4. Cadmium, copper, potassium and magnesium were found mainly in the cytosolic fraction.
• 5.5. Calcium, phosphorus and zinc were found in all isolated fractions, probably reflecting the important roles that these elements play in bivalve metabolism.
• 6.6. The organelle composition of the isolated subcellular fractions was determined using marker enzyme assays and microscopic techniques.

     

Axonal pathways of giant neurons identified in the right parietal and visceral ganglia in the suboesophageal ganglia of an African giant snail (Achatina fulica Férussac)

• 1.1. The axonal pathways of thirteen giant neurons identified in the right parietal and the visceral ganglia, found in the suboesophageal ganglia of an African giant snail (Achatina fulica Férussac), were investigated by intracellular injections of Lucifer Yellow, with regard to their axonal projections into the following six peripheral nerves: lap n (left anterior palliai nerve), lpp n (left posterior palliai nerve), int n (intestinal nerve), anal n (anal nerve), rpp n (right posterior palliai nerve) and rap n (right anterior palliai nerve).
• 2.2. These projections were confirmed by the recording of the axonal responses from the nerves.
• 3.3. On the dorsal surface of the right parietal ganglion, the following four giant neurons were identified: PON (periodically oscillating neuron), TAN (tonically autoactive neuron), RAPN (right anterior palliai neuron), and d-RPLN (dorsal-right parietal large neuron).
• 4.4. The PON axonal pathways projected into int n; those of TAN into all of the nerves examined; those of RAPN into lap n, lpp n, int n, anal n and rap n.; and those of d-RPLN into pd nn (pedal nerves) through the pedal ganglia, lpp n, anal n, rap n and sometimes lap n.
• 5.5. On the dorsal surface of the visceral ganglion, the following four giant neurons were also identified: VIN (visceral intermittently firing neuron), FAN (frequently autoactive neuron), INN (intestinal nerve neuron) and d-VLN (dorsal-visceral large neuron).
• 6.6. The VIN axonal pathways, which had no branch into the six nerves examined, went to both the right and the left pedal ganglia, sending a branch into the cerebro-pleural connective; those of FAN projected into lap n, anal n and rap n, and sometimes into lpp n and rpp n; those of INN into int n; and those of d-VLN into pd nn, lap n, lpp n, anal n and rap n.
• 7.7. On the ventral surface of the right parietal ganglion, v-RPLN (ventral-right parietal large neuron) was identified. The axonal pathways went to pd nn, lap n, lpp n, anal n and rap n.
• 8.8. On the ventral surface of the visceral ganglion, the four giant neurons, v-VNAN (ventral-visceral noisy autoactive neuron), v-VLN (ventral-visceral large neuron), r-VMN (right-visceral multiple spike neuron) and 1-VMN (left-visceral multiple spike neuron) were identified.
• 9.9. The axonal pathway of v-VNAN projected into rpp n and rap n; those of v-VLN into pd nn, lap n, anal n, rap n and sometimes to lpp n; those of r-VMN into int n and rpp n; and those of 1-VMN also into int n and rpp n.
• 10.10. The present morphologial investigations of the giant neurons confirmed well the identifications of the neurons previously studied. The axon of the neurons examined here, except for VIN, projected into some of the peripheral nerves, while the VIN axon extended into the cerebro-pleural connective.
• 11.11. The five neurons, PON, TAN, v-VNAN, r-VMN and 1-VMN, formed fine axonal arborizations terminating at the neuropile, while the arborizations of the other neurons were not clearly observed.
• 12.12. Although the anatomical structures of the portion examined of the suboesophageal ganglia are asymmetrical, three pairs of symmetrically-situated neurons, d-RPLN and d-VLN, v-RPLN and v-VLN, and r-VMN and 1-VMN, were found, indicating the existence of symmetrical components in the ganglia.

     

FMRFamide immunoreactive neurons in the central nervous system of the snail,Achatin a fulica

• 1.1. FMRFamide immunoreactive neurons were detected in the central nervous system of the snail, Achatina fulica.
• 2.2. FMRFamide immunoreactive neurons were found in all the ganglia comprising the central nervous system. In particular, the immunoreactivity was recognized in both the ordinary and giant neurons of the visceral and right parietal ganglia.
• 3.3. In the cerebral and pleural ganglia, FMRFamide immunoreactive neurons were found only in the ordinary neurons. The immunoreactivity was shown to have a tendency to form a group in the cerebral and pedal ganglia.

     

Metabolism in malleefowl (Leipoa ocellata)

• 1.1. Malleefowl Leipoa ocellata have a lower than predicted metabolic rate, a finding common to many arid adapted avian species.
• 2.2. Evaporative water loss was as expected by allometric analysis. However, in the wild this species probably reduces its evaporative water loss because their water turnover rate is extremely low.
• 3.3. Malleefowl coped with temperatures up to 40°C well, but above this temperature they become highly agitated.

     

Seasonal changes of circulating blood parameters in the grass snake Natrix natrix natrix L.

• 1.1. Seasonal changes of circulating blood parameters of Natrix n. natrix were evident and involved both sexes to the same extent.
• 2.2. A significant decrease in red cell count, haematocrit and haemaglobin concentration in the mating period, and an increase in those parameters and mean cell volume in autumn were observed, and haemodilution during winter torpor.
• 3.3. The changes during the breeding season had probably a hormonal background; in winter, they resulted first of all from a decreased erythropoietic activity and, to a lesser extent, from an increased red blood cell breakdown rate. However, the possibility that some erythrocytes were withdrawn from the circulation cannot be excluded.
• 4.4. Winter lymphocytopenia, eosinocytopenia and neutrophilic granulocytosis in females during egg laying were expressions of changes of leucocyte formula.
• 5.5. Seasonal cyclicity was found only with respect to the white cell count in males and the eosinophile fraction in males and females.
• 6.6. Probable reasons for, and mechanisms of the changes in blood composition are discussed.

     

Laboratory studies on the oxygen consumption of the marine teleost,Lichia amia (Linnaeus, 1758)

• 1.1. The oxygen consumption of the marine teleost, Lichia amia was investigated under controlled laboratory conditions.
• 2.2. The routine oxygen consumption showed a strong circadian rhythm with the fish being mainly active during the light period.
• 3.3. The specific mass exponent (dimension: μg O₂/g/hr) is temperature independent and ranges from 0.27–0.29.
• 4.4. Starving the fish results in a mean decrease in active, routine and standard oxygen consumption of 21%, 24% and 20%, respectively.
• 5.5. Feecling led to an increase in the oxygen consumption of the teleosts, with the mean metabolic rate over the 24 hr that followed, being 58% and 50% higher for fish that had been starved for 162hr and 40 hr, respectively.
• 6.6. Apparent SDA showed some variation and ranged from 6.0 to 35.5%.
• 7.7. The results obtained are generally in agreement with those recorded for other teleosts.

     

Lizard heart rate and motor activity relationships in the circadian and ultradian ranges

• 1.1. The heart rate and motor activity of lizards (Gallotia galloti) maintained in a light-dark cycle (12:12 hr) and with changing cyclic temperature were recorded. Both variables showed a circadian pattern, motor activity variations leading heart rate by approximately 110 min.
• 2.2. Results from cross spectral analysis showed that heart rate was highly correlated with temperature and both variables were changing practically in phase. However, motor activity and temperature were less correlated and in this case motor activity led temperature by approximately 100 min.
• 3.3. In the ultradian range, two periodicities could be distinguished in the power spectra of motor activity and heart rate variations during the day: one between 0.019 and 3.9 × 10⁻³ cycles/min (central peak around 85 min period) and another, of lower power, between 0.05 and 0.02 cycles/min (central peak around 34 min period). During the night, only the heart rate showed both periodicities but with a lower amplitude.
• 4.4. The presence of ultradian oscillations in heart rate during the night suggested that they do not depend on motor activity which was almost absent during that daily period.
• 5.5. Motor activity and heart rate were also highly correlated in the ultradian range, motor activity leading heart rate by around 5 min at the 85 min main peak.

     

The effect of eyestalk ablation on growth,haemolymph composition and gill Na+, K+-ATPase activity of Penaeus monodon juveniles

• 1.1. Eyestalk unablated and unilaterally ablated Penaeus monodon juveniles had survival rates after 5 months of 75–72.5 and 67.5–60%, respectively.
• 2.2. Unilaterally ablated shrimps had significantly higher (P < 0.05) growth rate than unablated shrimps.
• 3.3. Eyestalk-ablatement resulted in a decrease in the haemolymph sodium concentration and an increase in the potassium and calcium concentration of shrimps.
• 4.4. The osmolarity of haemolymph and total protein concentration of unablated shrimps were demonstrated to be higher than those of unilaterally ablated shrimps.
• 5.5. The eyestalk-ablated shrimps possess higher total ATPase and Na⁺,K⁺-ATPase activities in the gill than those of unablated shrimps.