Grierson J P, Neville A C
Tissue Cell. 1981;13(4):819-30. doi: 10.1016/s0040-8166(81)80016-x.
Previous publications show arced patterns in electron micrographs of either microfibrils or canals in sectioned fish eggshells, but these have been misinterpreted. We show here that such patterns in the inner layer of cod (Gadus morrhua), plaice (Pleuronectes platessa) and trout (Salmo gairdneri) eggs arise from a helicoidal structure. This consists of a laminate of protein microfibrils, with the direction of ply processing like the steps of a spiral staircase and with the same sense as a left-handed corkscrew. Mechanically, this is an ideal way to strengthen a spherical shell, to resist deforming forces equally from any direction. Radial canals which traverse this layer are forced into flattened and twisted ribbons. Both the helicoidal microfibrillar structure and the canal shape in fish eggshells show remarkable convergent evolution with similar structures in insect cuticles. Trout eggs were resistant to deforming forces as high as 380,000 N/m2. Fish eggshells, like those of many other organisms, are mechanically well designed.
以往的出版物显示，在切片鱼卵壳的微原纤维或管道的电子显微照片中存在弧形图案，但这些图案被误解了。我们在此表明，鳕鱼（Gadus morrhua）、鲽鱼（Pleuronectes platessa）和鳟鱼（Salmo gairdneri）卵内层的此类图案源自螺旋结构。它由蛋白质微原纤维的层状结构组成，其铺层方向如同螺旋楼梯的台阶，且与左旋开瓶器的方向一致。从力学角度来看，这是强化球形外壳、抵抗来自任何方向的变形力的理想方式。贯穿该层的径向管道被迫变成扁平且扭曲的带状。鱼卵壳中的螺旋微原纤维结构和管道形状与昆虫表皮中的类似结构呈现出显著的趋同进化。鳟鱼卵能够抵抗高达380,000 N/m² 的变形力。鱼卵壳与许多其他生物的卵壳一样，在力学设计上十分精巧。
