Norwegian University of Science and Technology, Department of Biology, Bynesveien 46, 7018, Trondheim, Norway.
GEOMAR - Helmholtz Centre for Ocean Research Kiel, Research Division Marine Ecology, Duesternbrooker Weg 20, 24105, Kiel, Germany.
Sci Rep. 2017 Nov 27;7(1):16419. doi: 10.1038/s41598-017-16346-w.
Many marine invertebrates including ctenophores are capable of extensive body regeneration when injured. However, as for the invasive ctenophore Mnemiopsis leidyi, there is a constant subportion of individuals not undergoing whole body regeneration but forming functionally stable half-animals instead. Yet, the driving factors of this phenomenon have not been addressed so far. This study sheds new light on how differences in food availability affect self-repair choice and regeneration success in cydippid larvae of M. leidyi. As expected, high food availability favored whole-body regeneration. However, under low food conditions half-animals became the preferential self-repair mode. Remarkably, both regenerating and half-animals showed very similar survival chances under respective food quantities. As a consequence of impaired food uptake after injury, degeneration of the digestive system would often occur indicating limited energy storage capacities. Taken together, this indicates that half-animals may represent an alternative energy-saving trajectory which implies self-repair plasticity as an adaptive trade-off between high regeneration costs and low energy storage capacities. We conclude that self-repair plasticity could lead to higher population fitness of ctenophores under adverse conditions such as in ships' ballast water tanks which is postulated to be the major vector source for the species' spreading around the globe.
许多海洋无脊椎动物，包括栉水母，在受伤时能够进行广泛的身体再生。然而，对于入侵性栉水母缘膜栉水母来说，总有一部分个体不会进行全身再生，而是形成功能稳定的半动物。然而，到目前为止，还没有解决这种现象的驱动因素。本研究揭示了食物供应的差异如何影响缘膜栉水母幼虫的自我修复选择和再生成功。正如预期的那样，高食物供应有利于全身再生。然而，在低食物条件下，半动物成为优先的自我修复模式。值得注意的是，在各自的食物数量下，再生和半动物的生存机会都非常相似。由于受伤后食物摄入减少，消化系统会退化，表明能量储存能力有限。总之，这表明半动物可能代表一种替代的节能轨迹，这意味着自我修复可塑性是高再生成本和低能量储存能力之间的一种适应性权衡。我们的结论是，自我修复可塑性可以使栉水母在不利条件下（如船舶压载水舱）的种群适应性更强，而船舶压载水舱被认为是该物种在全球范围内扩散的主要载体。
