Zoological Institute, Functional Morphology and Biomechanics, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany.
Department of Sedimentology, Kiel University, Otto-Hahn-Platz 1, 24118 Kiel, Germany.
Sci Rep. 2016 May 20;6:26308. doi: 10.1038/srep26308.
Flatfishes bury themselves for camouflage and protection. Whereas species-specific preferences for certain sediments were previously shown, the role of scales in interaction with sediment has not been investigated. Here, scale morphology and sediment friction were examined in four European pleuronectiforms: Limanda limanda, Platichthys flesus, Pleuronectes platessa, and Solea solea. All species had different scale types ranging from cycloid to ctenoid scales. On the blind side, the number of scales is higher and scales have less ctenial spines than on the eye side. The critical angle of sediment sliding (static friction) significantly depended on the grain size and was considerably higher on the eye side. The effect of mucus was excluded by repeated measurements on resin replicas of the skin. Our results demonstrate the impact of scale morphology on sediment interaction and give an insight about the ability of scales to keep sand. Exposed scales and a higher number of ctenial spines on the eye side lead to an increase of friction forces, especially for sediments with a smaller grain size. Our results suggest that the evolution of scales was at least partly driven by their interactions with sediment which confirms the relevance of sediment for the distribution and radiation of Pleuronectiformes.
比目鱼为了伪装和保护而将自己埋起来。尽管之前已经显示出某些特定沉积物的物种特异性偏好，但鳞片与沉积物相互作用的作用尚未得到研究。在这里，研究了欧洲比目鱼中的四种鱼类的鳞片形态和沉积物摩擦力：欧鲽、欧洲牙鲆、欧洲鲈鱼和欧洲鳎。所有物种的鳞片类型均不同，从圆鳞到栉鳞。在盲侧，鳞片数量较多，栉齿刺比眼侧少。沉积物滑动的临界角度（静摩擦力）显着取决于粒度，并且在眼侧要高得多。通过对皮肤的树脂复制品进行重复测量排除了粘液的影响。我们的结果表明了鳞片形态对沉积物相互作用的影响，并深入了解了鳞片保持沙子的能力。暴露的鳞片和眼侧更多的栉齿刺会导致摩擦力增加，尤其是对于粒度较小的沉积物。我们的结果表明，鳞片的进化至少部分是由其与沉积物的相互作用驱动的，这证实了沉积物对比目鱼分布和辐射的重要性。
