Mendt Shannon R, Gosselin Louis A
Department of Biological Sciences Thompson Rivers University Kamloops BC Canada.
Ecol Evol. 2021 Jun 6;11(13):8882-8896. doi: 10.1002/ece3.7723. eCollection 2021 Jul.
Insufficient energy reserves are widely considered to be a primary factor contributing to high rates of early benthic phase mortality among benthic marine invertebrates, but this hypothesis has been based mostly on indirect, observational evidence, and remains largely untested. We therefore examined the role of initial energy reserves in regulating survivorship and growth during the early benthic phase. Recently settled or hatched individuals of six invertebrate species were collected from natural populations, maintained without food, and their survivorship was monitored. Contrary to expectations, starved individuals of all six species had high survivorship through the critical first 10 days of the early benthic phase, with half of the species experiencing <2% mortality, and the remaining three species experiencing only 6%-12% mortality. For five of the six species, 50% mortality was reached only after ≥50 days of starvation. Additionally, no difference in short-term survivorship was detected among starved individuals of three different size classes (a proxy for energy reserves) of . ostrina hatchlings. Finally, the effect of different durations of delayed feeding (0-50 days) on recovery (i.e., growth and survivorship) once food was made available revealed that duration of starvation prior to feeding can nevertheless have significant longer-term impacts on the proportion of individuals that survive or their ability to grow. Together, these findings suggest that depleted energy reserves are not a primary cause of high mortality at the start of the early benthic phase, as had previously been hypothesized. Levels of energy reserves did influence growth, however, suggesting a possible indirect influence on performance by leaving individuals vulnerable for longer periods.
能量储备不足被广泛认为是导致海洋底栖无脊椎动物早期底栖阶段高死亡率的主要因素，但这一假设大多基于间接的观察证据，且在很大程度上仍未得到验证。因此，我们研究了初始能量储备在调节底栖早期阶段的存活率和生长方面的作用。从自然种群中收集了六种无脊椎动物最近定居或孵化的个体，在不喂食的情况下进行饲养，并监测它们的存活率。与预期相反，所有六个物种的饥饿个体在底栖早期至关重要的前10天内都有很高的存活率，其中一半物种的死亡率低于2%，其余三个物种的死亡率仅为6%-12%。对于六个物种中的五个，只有在饥饿≥50天后才达到50%的死亡率。此外，在.ostrina幼体的三个不同大小等级（作为能量储备的指标）的饥饿个体中，未检测到短期存活率的差异。最后，不同延迟喂食时间（0-50天）对食物供应后恢复（即生长和存活）的影响表明，喂食前的饥饿持续时间仍然可能对存活个体的比例或其生长能力产生显著的长期影响。总之，这些发现表明，能量储备耗尽并非如先前假设的那样是底栖早期开始时高死亡率的主要原因。然而，能量储备水平确实影响生长，这表明可能通过使个体在更长时间内易受伤害而对其表现产生间接影响。
