Reply to Horizons Article ‘Some ideas about the role of lipids in the life cycle of Calanus finmarchicus’ Irigoien (2004): II
Reply to Horizons Article ‘Some ideas about the role of lipids in the life cycle of Calanus finmarchicus’ Irigoien (2004): II
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回复 Horizons 文章《关于脂质在 Calanus finmarchicus 生命周期中的作用的一些想法》Irigoien (2004): II
DOI：
10.1093/plankt/fbh113
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发表时间：
2004
影响因子：
2.1
通讯作者：
S. Kaartvedt
中科院分区：
文献类型：
--
作者：
Ø. Fiksen;Ø. Varpe;S. Kaartvedt
最近，Irigoien(Irigoien，2004)提出了类脂在海洋桡足类Calanus finmarchicus生活史中的作用的概念模型。正如他指出的，过冬前积累的脂肪传统上被视为能量储备，以满足滞育期间的新陈代谢需求。然而，在滞育期间，Finmarchicus可能几乎没有代谢成本(Jonasdottir，1999)，大量的脂肪储存仍然停留在觉醒阶段。如果这是正确的，那么解决能量分配的最佳性的模型假设在0.001(费克森，2000年)到0.008(费克森和卡洛蒂，1998年)g�1day�1的范围内的特定静息代谢率太高。因此，在这些模型中，基本代谢需求是能量储存(脂肪积累)的主要原因，尽管预测脂肪分配会在多余脂肪用于产卵或换羽、性腺形成和相关过程时增加。由于代谢成本低，这些模型预测多一代或更长的滞育时间，而不是脂肪储存，是最优的生活史策略。Irigoien没有提到捕食也可能解释了早期下降到越冬栖息地的原因。在挪威海，Finmarchicus是许多鱼类喜欢的猎物，由于白天较长，以及浮游性鱼类(挪威春季产卵的鲱鱼、蓝鲸和鲱鱼)的到来，捕食风险随着时间的推移而增加(Kaartwedt，2000)。此外，与构建体细胞组织的更复杂过程相比，储存脂肪和蛋白质耗费的时间更少，在下个季节之前，在深处储存体细胞组织可能会更安全。通过为卵提供更多的资源，后代也能够在水华之前发育，并进一步减少一生中接触到鱼类捕食者。然而，早期繁殖的明显的健康优势仍然有待量化，如果越冬期间代谢成本可以忽略不计，我们没有一个一致的理论来解释为什么Finmarchicus作为资本繁殖者而不是
Recently, Irigoien (Irigoien, 2004) suggested a conceptual model of the role of lipids in the life cycle of the marine copepod Calanus finmarchicus. As he pointed out, lipids accumulated before overwintering have traditionally been regarded as an energy reserve to supply metabolic needs during diapause. However, C. finmarchicus may have practically no metabolic costs during diapause ( Jonasdottir, 1999), with large lipid stores remaining at arousal. If this is correct, then models addressing the optimality of the energy allocation in C. finmarchicus assumed a specific resting metabolic rate that was too high, in the range of 0.001 (Fiksen, 2000) to 0.008 (Fiksen and Carlotti, 1998) g g � 1 day � 1 . Consequently, basic metabolic requirements was the primary reason for ‘energy storage’ (lipid accumulation) in these models, although predicted fat allocation increased when excess fat could be used for egg production or moulting, gonad formation and related processes. With low metabolic costs, these models predict an extra generation or longer diapause instead of fat storage as optimal life history strategy. Irigoien did not mention that predation may also explain the early descent to overwintering habitats. In the Norwegian Sea, C. finmarchicus are favoured prey of many fishes, and due to longer days and the arrival of planktivorous fish (Norwegian spring spawning herring, blue whiting and mackerel) predation risk increases with time (Kaartvedt, 2000). In addition, storage of fat and proteins is less time consuming than the more complex processes of building somatic tissues, which may be done more safely at depths before next season. By providing eggs with more resources, offspring are also able to develop in advance of the bloom, and further reduce lifetime exposure to fish predators. However, the explicit fitness advantages of early reproduction remain to be quantified, and if there are negligible metabolic costs during overwintering, we do not have a consistent theory for why C. finmarchicus act as a ‘capital breeder’ instead of