Université Côte d'Azur, CNRS, FRE 3729 ECOMERS, Avenue Valrose 28, 06108, Nice, France.
CoNISMa, Piazzale Flaminio 9, 00196, Rome, Italy.
Sci Rep. 2018 Jun 15;8(1):9193. doi: 10.1038/s41598-018-27491-1.
Dark marine habitats are often characterized by a food-limited condition. Peculiar dark habitats include marine caves, characterized by the absence of light and limited water flow, which lead to reduced fluxes of organic matter for cave-dwelling organisms. We investigated whether the most abundant and common cave-dwelling fish Apogon imberbis has the potential to play the role of trophic vector in Mediterranean marine caves. We first analysed stomach contents to check whether repletion changes according to a nycthemeral cycle. We then identified the prey items, to see whether they belong to species associated with cave habitats or not. Finally, we assessed whether A. imberbis moves outside marine caves at night to feed, by collecting visual census data on A. imberbis density both inside and outside caves, by day and by night. The stomach repletion of individuals sampled early in the morning was significantly higher than later in the day. Most prey were typical of habitats other than caves. A. imberbis was on average more abundant within caves during the day and outside during the night. Our study supports the hypothesis regarding the crucial trophic role of A. imberbis in connecting Mediterranean marine caves with external habitats.
黑暗的海洋生境通常以食物有限为特征。奇特的黑暗生境包括海洋洞穴，其特点是没有光和有限的水流，这导致洞穴生物的有机物质通量减少。我们研究了最丰富和最常见的洞穴栖息鱼类 Apogon imberbis 是否有可能在地中海海洋洞穴中发挥营养载体的作用。我们首先分析了胃内容物，以检查充盈度是否根据昼夜节律而变化。然后，我们确定了猎物的种类，看看它们是否属于与洞穴栖息地相关的物种。最后，我们通过白天和夜间在洞穴内外收集 Apogon imberbis 密度的视觉普查数据，评估 A. imberbis 是否在夜间离开海洋洞穴去觅食。清晨采集的个体的胃充盈度明显高于当天晚些时候。大多数猎物都是洞穴以外栖息地的典型代表。A. imberbis 白天在洞穴内的平均丰度更高，而夜间在洞穴外的丰度更高。我们的研究支持了关于 A. imberbis 在连接地中海海洋洞穴与外部栖息地方面具有关键营养作用的假设。
