Polypeptide models of the arthropodin protein of the barnacle Balanus balanoides

1992 ◽  
Vol 37 (1-2) ◽  
pp. 131-143 ◽  
Author(s):  
Hiroyuki Yamamoto ◽  
Akira Nagai
Keyword(s):  
Author(s):  
D.J. Crisp ◽  
F.J. Maclean

The expected allometry between the linear cirral length and animal volume or weight for isometry should be 0·33; similarly the rate of beating, db/dt, might also be expected to increase as −0·33 with volume. The average allometry index of cirral length is less in both Balanus balanoides (0·22–0·23) and in Elminius modestus (0·27–0·32). The segment numbers also rise less than expected.The rate of beat in Balanus balanoides correlates well with size (-0·28) and with temperature with a correlation coefficient of 0·898, significant for both variables. For a group of 11 species the relation between maximum rate of beating and size over 5 decades gives an approximate allometry of −0·24 which is also less than the expected −0·33 for an isometric linear appendage moving at constant velocity. It is suggested that the approximately reciprocal allometry index between cirral beating rate (−0·28) and cirral length (+0·22) may be mutually compensating, resulting in the cirri moving through the water at a constant rate during the growth of the animal. This rate may maximise the chance of prey being captured.


Author(s):  
R. C. Newell ◽  
H. R. Northcroft

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.


Author(s):  
M. I. Lucas ◽  
D. J. Crisp†

The partitioning and utilization of energy reserves during embryogenesis were followed in the cirripede Balanus balanoides and related to the described sequence of developmental stages. Egg volume and dry weights were measured. Between the recently fertilized egg and eggs containing well-developed embryos at the end of natural incubation there is a doubling of egg volume.The biochemical composition of the newly fertilized egg is dominated by TCA-insoluble protein (55 %). Neutral lipid accounts for 17 % of the dry weight, while phospholipid and polysaccharide contribute 3–5% and 5–7% respectively. About 36% of the TCA-insoluble protein is utilized during in vivo development, accounting for about three-quarters of the energy expenditure. During this time 40% of the carbohydrate and 20% of the neutral lipid reserves are also utilised. However, when starved adults retain their mature egg masses beyond the normal term, egg metabolism occurs largely at the expense of the remaining lipid reserves. These would be exhausted in a further 6–7 weeks and the embryos unable to survive. The ability of adults to postpone hatching may therefore have important implications for the energy reserves and viability of the newly hatched nauplii. Protein supplies most of the energy during embryogenesis, with neutral lipid assuming increased importance after development has been completed.Oxygen consumption of the egg masses measured in vitro was converted through aerobic oxycalorific equivalent into biochemical loss. This showed good agreement with direct measurement of summed energy losses of the biochemical components. It was apparent that oxygen uptake rate in the later stages was restricted by diffusion resistance due to egg packing, since eggs freed from the egg mass matrix showed a 30% increase in oxygen uptake and a reduction in development time.


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