Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environmental Sciences, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel.
Texas Parks and Wildlife Department, Coastal fisheries, Port Arthur Marine Lab, 601 Channel view drive, Port Arthur, TX 77640 USA.
Acta Biomater. 2020 Mar 1;104:28-38. doi: 10.1016/j.actbio.2020.01.001. Epub 2020 Jan 7.
Durophagous fish consume a diet based primarily on hard-shelled animals, mainly mollusks. In order to successfully perform this task, they are equipped with an extra set of jaws located in their throat called pharyngeal jaws. Here we present the results of a study of the structure of the bony material of the exceptionally powerful lower pharyngeal jaws (LPJs) of the black drum Pogonias cromis which generate the highest biting forces documented in bony fishes. In particular, we studied the two long and slender struts that support the entire dental plate and teeth of the LPJ, in order to determine how this structure withstands the huge stresses it encounters repetitively and for long periods of time. We describe the hierarchical structure of the struts of lower pharyngeal jaw of P. cromis at a wide range of length scales, and show how it is adapted to successfully achieve its high mechanical performance. In particular, we show that the bone material of the strut is neither cortical nor cancellous, and although it is highly porous, its complex and layered three-dimensional arrangement of thick lamellae sheets, which are inter-connected by thin plates, is perfectly tailored to withstand extremely large but directionally-consistent forces. STATEMENT OF SIGNIFICANCE: The diet of some fish consists of hard food, like mollusks and shells. In order to accomplish the task of cracking this type of food, they have an extra set of bony jaws located in their throat, called pharyngeal jaws. Here we describe the hierarchical structural elements of these jaws which allow them to withstand huge forces repeatedly over long periods of time. Surprisingly, the structure is very porous, but its architectural design is superbly adapted to handle consistently-oriented forces. This structural motif defines a new bony material which is neither cortical nor cancellous.
食硬骨鱼的食物主要以硬壳动物为基础，主要是软体动物。为了成功完成这项任务，它们的喉咙里有一套额外的下颚，称为咽颚。在这里，我们展示了对黑鲈（Pogonias cromis）异常强大的下咽颚（LPJ）的骨状物质结构的研究结果，该鱼产生了有记录以来硬骨鱼中最高的咬合力。特别是，我们研究了支撑 LPJ 整个牙板和牙齿的两个长而细长的支柱，以确定这种结构如何承受它反复长时间遇到的巨大压力。我们描述了 P. cromis 下咽颚支柱的结构在广泛的长度尺度上的层次结构，并展示了它如何适应成功实现其高机械性能。特别是，我们表明支柱的骨状材料既不是皮质的也不是松质的，尽管它的多孔性很高，但它的复杂且分层的三维厚薄片层状结构，通过薄片相互连接，非常适合承受非常大但方向一致的力。意义陈述：一些鱼的饮食包括硬食物，如软体动物和贝壳。为了完成这种类型的食物的任务，它们的喉咙里有一套额外的骨质下颚，称为咽颚。在这里，我们描述了这些下颚能够反复长时间承受巨大力量的层次结构元素。令人惊讶的是，该结构非常多孔，但它的建筑设计非常适合处理一致的定向力。这种结构模式定义了一种新的骨状材料，既不是皮质的也不是松质的。
