Seasonal changes in the biochemical composition and oxygen consumption of the sea anemone Actinia equina as related to body size and shore level

1988 ◽  
Vol 97 (1) ◽  
pp. 137-143 ◽  
Author(s):  
M. M. Ortega ◽  
J. M. Lopez de Pariza ◽  
E. Navarro
1968 ◽  
Vol 48 (2) ◽  
pp. 427-434
Author(s):  
A. E. BRAFIELD

1. The oxygen consumption of the echiuroid Bonellia viridis has been investigated by means of a continuous-flow polarographic respirometer. 2. The general rate of oxygen consumption per unit dry weight is similar to that characteristic of polychaetes, and declines exponentially with increasing body size. 3. The rate of oxygen consumption rises in the light and falls again if darkness is restored. 4. The oxygen consumption of the isolated proboscis plus that of the isolated body region corresponds closely to that of the entire animal. 5. The oxygen consumption per unit dry weight of the proboscis is considerably higher than that of the body region. 6. The oxygen consumption of an isolated body region increases in the presence of light, but that of an isolated proboscis does not. 7. These findings are discussed in relation to the biology of the animal, observed muscular activity, and the occurrence of the pigment bonellin.


1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.


2008 ◽  
Vol 33 (4) ◽  
pp. 735-742 ◽  
Author(s):  
Aldo Sassi ◽  
Franco M. Impellizzeri ◽  
Andrea Morelli ◽  
Paolo Menaspà ◽  
Ermanno Rampinini

The primary purpose of this study was to compare seasonal changes in cycling gross efficiency (GE) and economy (EC) with changes in other aerobic fitness indices. The secondary aim was to assess the relationship between maximum oxygen consumption, GE, and EC among elite cyclists. The relationships of maximum oxygen consumption with GE and EC were studied in 13 cyclists (8 professional road cyclists and 5 mountain bikers). Seasonal changes in GE and EC, predicted time to exhaustion (pTE), maximum oxygen consumption, and respiratory compensation point (RCP) were examined in a subgroup of 8 subjects, before (TREST) and after (TPRECOMP) the pre-competitive winter training, and during the competitive period (TCOMP). GE and EC were assessed during a constant power test at 75% of peak power output (PPO). Significant main effect for time was found for maximum oxygen consumption (4.623 ± 0.675, 4.879 ± 0.727, and 5.010 ± 0.663 L·min–1; p = 0.028), PPO (417.8 ± 46.5, 443.0 ± 48.0, and 455 ± 48 W; p < 0.001), oxygen uptake at RCP (3.866 ± 0.793, 4.041 ± 0.685, and 4.143 ± 0.643 L·min–1; p = 0.049), power output at RCP (330 ± 64, 354 ± 52, and 361 ± 50 W; p < 0.001), and pTE (17 ± 4, 30 ± 8, and 46 ± 17 min; p < 0.001). No significant main effect for time was found in GE (p = 0.097) or EC (p = 0.225), despite within-subject seasonal changes. No significant correlations were found between absolute maximum oxygen consumption and GE (r = –0.276; p = 0.359) or EC (r = –0.328; p = 0.272). However, cyclists with high maximum oxygen consumption values (i.e., over 80 mL·kg–1·min–1), showed low efficiency rates. Despite within-subject seasonal waves in cycling efficiency, changes in GE and EC should not be expected as direct consequence of changes in other maximal and submaximal parameters of aerobic fitness (i.e., maximum oxygen consumption and RCP).


2004 ◽  
Vol 313 (1) ◽  
pp. 63-73 ◽  
Author(s):  
O. Chomsky ◽  
Y. Kamenir ◽  
M. Hyams ◽  
Z. Dubinsky ◽  
N.E. Chadwick-Furman

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