Influence of season, size, and temperature on the metabolism of an arctic cydippid ctenophore, Mertensia ovum (Fabricius)
1988; Taylor & Francis; Volume: 73; Issue: 1 Linguagem: Inglês
10.1080/00364827.1988.10420672
ISSN1503-1128
Autores Tópico(s)Aquatic Ecosystems and Phytoplankton Dynamics
ResumoAbstract The arctic cydippid ctenophore Mertensia ovum reduces its metaholic rate during the winter when food is scarce. The rate of oxygen consumption declines hy almost one-third. while the rate of ammonia excretion decreases hy two-thirds. In the winter the OIN ratio is douhle that in the summer. This suggests that the animal shifts towards a more lipid oriented metaholism in the winter. Similar results were ohtained whether the rates were measured in situ at the amhient water temperature or in the lahoratory at a uniform 0°C. Winter animals are almost 40 % heavier. in terms of hoth wet and dry weight. than summer animals of the same length. Between ()° and 7°C the Q10 for respiration is 2.1 and for ammonia excretion 1.7. Ahove 7°C. the Q10 values rise sharply and variation in the rates increases. indicating thermal stress and impairment of metaholic regulation. The 0/N ratio is maximal at 4.5°C. The oxygen consumption and ammonia excretion rales per unit weight hoth decrease with increasing animal weight. with 'h' coefficients ranging from 0.546 to 0.744. The 0/N ratio does not vary with animal size.
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