Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
National Research Institute of Fisheries and Environment of Inland Sea, Japan Fisheries Research and Education Agency, Imabari, Ehime, Japan.
PLoS One. 2019 Mar 7;14(3):e0213611. doi: 10.1371/journal.pone.0213611. eCollection 2019.
Capital breeders develop gametes by using energy that was stored before the spawning season. Energy is allocated to growth and reproduction, and limited food availability affects the balance of energy allocation, especially in fish that mature within a year, such as western sand lance (Ammodytes japonicus). This species aestivates without feeding until winter spawning and utilize energy stores that were accumulated prior to aestivation for maturation and spawning. This study aimed to evaluate the growth, energy storage, maturation rate, and reproduction of A. japonicus in response to food availability before aestivation. We conducted laboratory experiments in which young-of-the-year A. japonicus were fed at rates of 4% and 1% of their body weight per day; assigned as high and low ration groups, respectively. In June, body length was found to be significantly larger in the high ration group than in the low ration group, but the somatic condition did not differ significantly between the groups. Maturation rates and average fecundities were 1.0 and 6297 in the high ration group and 0.8 and 2251 in the low ration group, respectively. These results indicate that food availability before aestivation strongly governs the reproductive potential of A. japonicus, and suggest the involvement of mechanisms in the inter-annual recruitment variation in sand lance species.
育肥群体通过利用繁殖季节前储存的能量来产生配子。能量分配用于生长和繁殖，有限的食物供应会影响能量分配的平衡，特别是在一年内成熟的鱼类中，如西部美洲拟沙丁鱼（Ammodytes japonicus）。这种鱼类在夏季休眠期间不进食，直到冬季繁殖，然后利用在休眠前积累的能量储备来完成成熟和繁殖。本研究旨在评估在休眠前食物可获得性对 A. japonicus 的生长、储能、成熟率和繁殖的影响。我们进行了实验室实验，其中将当年幼鱼 A. japonicus 以其体重的 4%和 1%的速率喂食；分别分配为高和低摄食组。6 月时，高摄食组的体长明显大于低摄食组，但两组之间的体况没有显著差异。高摄食组的成熟率和平均产卵量分别为 1.0 和 6297，低摄食组的分别为 0.8 和 2251。这些结果表明，休眠前的食物可获得性强烈影响 A. japonicus 的生殖潜力，并表明在美洲拟沙丁鱼属的年度间补充变化中存在机制的参与。
