Department of Physiology, University of Birmingham, Edgbaston, Birmingham, U.K.
J Fish Biol. 2009 Feb;74(3):535-52. doi: 10.1111/j.1095-8649.2008.02141.x.
Extrinsic neural and humoral influences on heart rate (fH) and ventilation frequency (fV) were examined following varying periods of post-surgical recovery in eight related Antarctic fish species inhabiting an array of inshore niches. Resting fH after recovery from handling was lower than previous reports, and the novel measurement of routine fH in free-swimming Dissostichus mawsoni (6.14 beats min(-1), bpm) is the lowest recorded for any fish. The extent of cardio-depressive cholinergic (vagal) tonus explained the large range of fH among species and varied with behavioural repertoire, being lower in the more active species, apart from Notothenia coriiceps. Adrenergic tonus was low compared with cholinergic tonus, with the exception of Trematomus newnesi. Hence, high cardiac cholinergic tonus may be a genotypic trait of the notothenioids that diverged with ecotype. Power spectral analysis showed that the vagal influence produced comparable spectra among species of similar morphology and ecotype. Removal of autonomic tonus resulted in a remarkably similar intrinsic fH between species. Simultaneous measurements of cardio-respiratory variables and oxygen consumption (M(O(2))) were made in the benthic Trematomus bernacchii and cryopelagic Pagothenia borchgrevinki. The slopes of the relationship between fH and M(O(2)) were similar. Trematomus bernacchii, however, had a higher M(O(2)) for a given fH than P. borchgrevinki, and P. borchgrevinki required a two-fold larger range in fH to reach a similar maximum M(O(2)), suggesting that there is a difference in cardiovascular fitness between the two species. Overall, the data suggest that cardio-respiratory control in Antarctic nototheniids is largely determined by activity levels associated with a given ecotype.
在 8 种生活在近海小生境的南极鱼类中，研究了手术后恢复期不同时间对心率（fH）和通气频率（fV）的外在神经和体液影响。与之前的报道相比，恢复期后处理的静息 fH 较低，而在自由游动的犬牙鱼（Dissostichus mawsoni）中测量到的常规 fH 的新值（6.14 次/分钟，bpm）是所有鱼类中记录到的最低值。心抑制性胆碱能（迷走）张力的程度解释了物种间 fH 的大范围变化，并随行为范围而变化，在更活跃的物种中较低，除了 Notothenia coriiceps 以外。与胆碱能张力相比，肾上腺素张力较低，除了 Trematomus newnesi 以外。因此，高心脏胆碱能张力可能是与生态型分化的南极鳕鱼的遗传特征。功率谱分析表明，在形态和生态型相似的物种中，迷走神经的影响产生了相似的频谱。去除自主张力后，物种之间的固有 fH 非常相似。在底栖 Trematomus bernacchii 和低温 Pagothenia borchgrevinki 中同时测量了心肺变量和耗氧量（M(O(2)))。fH 和 M(O(2)) 之间关系的斜率相似。然而，对于给定的 fH，Trematomus bernacchii 的 M(O(2)) 较高，而 P. borchgrevinki 则需要两倍大的 fH 范围才能达到相似的最大 M(O(2))，这表明两种物种之间的心血管适应能力存在差异。总的来说，这些数据表明，南极鳕鱼的心肺控制在很大程度上取决于与特定生态型相关的活动水平。
