Department of Biology, Carleton College, Northfield, Minnesota, USA.
Department of Biology, George Washington University, Washington, District of Columbia, USA.
J Morphol. 2022 Feb;283(2):164-173. doi: 10.1002/jmor.21435. Epub 2022 Jan 6.
Predation, combat, and the slings and arrows of an abrasive and high impact environment, represent just some of the biotic and abiotic stressors that fishes are armored against. The Pacific Spiny Lumpsucker (Eumicrotremus orbis) found in the subtidal of the Northern Pacific Ocean is a rotund fish covered with epidermal, cone-shaped, enamel odontodes. The Lumpsucker is a poor swimmer in the wave swept rocky intertidal, and this armor may be a lightweight solution to the problem of collisions with abiotic obstacles. We use micro-CT and scanning electron microscopy to reveal the morphology and ontogeny of the armor, and to quantify the amount of mineralization relative to the endoskeleton. The non-overlapping odontodes are organized into eight rows-six rows on the body, one row surrounding the eye, and one row underneath the chin. Odontodes start as a single, hooked cone; and they grow by the addition of cusps that accrete into a spiral. The mineral investment in armor compared to skeleton increases over ontogeny. Damage to the armor occurs both through passive abrasion and breakage from impact; and there is no evidence of replacement, or repair of damaged odontodes.
捕食、战斗以及来自恶劣和高冲击环境的压力，只是鱼类所面临的部分生物和非生物胁迫因素。北太平洋潮间带发现的太平洋刺盖鱼（Eumicrotremus orbis）是一种圆胖的鱼类，全身覆盖着表皮、锥形、釉质的齿状突起。刺盖鱼在波涛汹涌的多岩石潮间带游泳能力很差，而这种盔甲可能是解决与无生命障碍物碰撞问题的轻量级解决方案。我们使用微计算机断层扫描和扫描电子显微镜来揭示盔甲的形态和发育，并定量分析与内骨骼相关的矿化程度。不重叠的齿状突起分为八排——身体上有六排，一排围绕眼睛，一排位于下巴下方。齿状突起最初是一个单独的、钩状的锥形突起；它们通过添加不断累积成螺旋状的小齿来生长。随着发育，盔甲的矿化投资相对于骨骼增加。盔甲的损伤既有被动磨损造成的，也有因冲击而断裂造成的；没有证据表明受损的齿状突起会被替换或修复。
