Fixation and preservation contribute to distortion in vertebrate museum specimens: a ten-year study with the lizard Anolis sagrei

Preservation of museum specimens depends on chemical fixation and preservation, processes that might distort the original material. Relatively few studies have examined preservation effects in potentially susceptible soft-bodied taxa like herpetofauna, and those that have rarely extend over more than a few months. We collected six common morphological measurements from the same set of radiographed specimens of the Neotropical lizard Anolis sagrei over nearly ten years to investigate whether morphometric changes result from fixation in formalin and/or subsequent long-term preservation in ethanol. Snout-vent length (SVL) declined 3.5% on average over 10 years, starting almost immediately with fixation and continuing to decline during fluid preservation, eventually leveling off at 40 weeks and beyond. The mostly-ossified component of SVL, spine length, declined 2% on average, but the decline did not begin until fluid preservation commenced and continued throughout the duration of the study...博物馆标本的保存依赖化学固定与保存流程，而此类过程可能会对原始标本材料造成畸变。目前针对两栖爬行动物（herpetofauna）这类潜在易受影响的软躯体类群开展的相关研究相对较少，且已有的相关研究鲜有持续时长超过数月者。本研究对同一批新热带区蜥蜴棕安乐蜥（Anolis sagrei）的射线照相标本进行了长达近十年的跟踪采样，获取了六项常规形态学测量数据，旨在探究福尔马林固定及后续乙醇长期保存是否会引发形态测量学层面的变化。研究结果显示，吻肛长（Snout-vent length, SVL）在十年间平均下降3.5%，该下降趋势几乎从固定工序启动时便已出现，并在液体保存阶段持续进行，最终在40周及之后趋于平稳。吻肛长中以骨化为主的组成部分——脊柱长度，平均下降2%，但该下降趋势直至液体保存环节启动后才开始出现，并在本研究的整个周期内持续发生……