Oxygen Consumption Rates and Metabolic Enzyme Activities of Oceanic California Medusae in Relation to Body Size and Habitat Depth.
Oxygen Consumption Rates and Metabolic Enzyme Activities of Oceanic California Medusae in Relation to Body Size and Habitat Depth.
复制标题
海洋加州水母的耗氧率和代谢酶活性与体型和栖息地深度的关系。
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
J. Childress
中科院分区：
文献类型：
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作者：
E. V. Thuesen;J. Childress
本文测定了14种水螅水母和5种深海冠状水母的耗氧率。所有个体的所有种类的水母的分析表明，减少比耗氧率与增加动物的湿重的共同模式。测定了30多种水母的柠檬酸合成酶（CS）、乳酸脱氢酶（LDH）、苹果酸脱氢酶（MDH）和丙酮酸激酶（PK）活性。章鱼碱脱氢酶，strombine脱氢酶，丙氨酸脱氢酶没有检测到水螅水母或scyphomedusae。三羧酸循环酶活性存在个体较大时活性降低的异速生长标度现象。LDH活性，另一方面，增加湿重。大多数水母有氧平衡，具有较高的CS活动比LDH活动。然而，一些中层和深海水母，包括冠状scyphozoans Periphylla periphylla和Nausitho{e2 dot} rubra，厌氧平衡，可能作为一种机制，以协助垂直迁移在低氧浓度的氧气最低层。有CS活动和耗氧率在这些水母相比，以前调查的动物之间的相关性差。为了解释这种较差的相关性，我们提出假设，水母CS在外围的最大扩散距离可能是氧限制，并不正常的体内速率。对于远洋水母，除了温度随深度降低所引起的下降外，酶活性所确定的代谢率和代谢潜力随深度增加没有明显下降。这些模式与在中上层鱼类和甲壳类动物中观察到的代谢率和代谢潜力随深度迅速下降形成对照。深海水母的代谢率与深海鱼类和甲壳类动物的代谢率相似。
Oxygen consumption rates were measured in 14 species of hydromedusae and 5 species of bathypelagic coronate scyphomedusae. Analysis of all individuals of all species of medusae showed the familiar pattern of decreasing specific oxygen consumption rate with increasing wet weight of animals. Citrate synthase (CS), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), and pyruvate kinase (PK) activities were measured in more than 30 species of medusae. Octopine dehydrogenase, strombine dehydrogenase, and alanopine dehydrogenase were not detected in either hydromedusae or scyphomedusae. The allometric scaling phenomenon of decreasing activity in larger individuals was observed in Krebs cycle enzyme activities. LDH activities, on the other hand, increased with increasing wet weight. Most medusae were aerobically poised, with higher CS activities than LDH activities. However, several meso- and bathypelagic medusae, including the coronate scyphozoans Periphylla periphylla and Nausitho{e2dot} rubra, were anaerobically poised, possibly as a mechanism to assist in vertical migrations at low oxygen concentrations in the oxygen minimum layer. There is poor correlation between CS activities and oxygen consumption rates in these medusae when compared to previously investigated animals. To account for this poor correlation, we propose the hypothesis that medusan CS at the periphery of the maximum diffusion distance may be oxygen-limited and does not function at the normal in vivo rate. For pelagic medusae, there is no apparent decline in metabolic rate and metabolic potential, as determined by enzymatic activity, with increasing depth of occurrence, beyond the declines caused by the decrease in temperature with depth. These patterns are in contrast to the rapid declines in metabolic rates and metabolic potentials with depth that have been observed for pelagic fishes and crustaceans. Deep-living medusae have metabolic rates of a magnitude similar to those of bathypelagic fishes and crustaceans.