Institute of Parasitic Diseases, 11445 E. Via Linda 2-419, Scottsdale, Arizona85259, USA.
Department of Biology, Brigham Young University, 1114 MLBM, Provo, Utah84602, USA.
J Helminthol. 2021 Dec 13;95:e73. doi: 10.1017/S0022149X21000675.
We make new morphological observations not previously reported for the old acanthocephalan Macracanthorhynchus hirudinaceus (Pallas, 1781) Travassos, 1917, described for the first time about 240 years ago. Our specimens were collected from the wild boar, Sus scrofa Linn., in Ukraine in 2005. We provide comparative morphometrics with other populations from Ukraine, Union of Soviet Socialist Republics, Europe, Brazil and the United States of America. Our specimens from the Ukraine had the smallest trunk (110-120 mm long), longest and thickest hooks, with the third hook being the largest, largest eggs, and a proboscis wider than long. We document the morphology of the proboscis, apical organ, hooks, hook roots, sensory pores, micropores, and eggs with scanning electron microscopy for the first time. We also provide chemical analysis of hooks and eggs using energy-dispersive X-ray analysis, discuss its micropores, and provide a new molecular profile based on 18S rDNA from a European population for the first time. Edge of hook tips feature high levels of calcium and phosphorous but the high level of sulphur is mostly found in the cortical layer of eggs. One new partial 18S rDNA sequence (482 nt length) was generated from an adult specimen of M. hirudinaceus. We present the first 18S rDNA published sequence for this cosmopolitan acanthocephalan obtained from Europe. The amplified region corresponded to the approximate middle region of the small subunit ribosomal ribonucleic acid gene, which is ~1800 nt in length. This molecular contribution is especially valuable in light of the extreme scarcity of genetic information about species of Macracanthorhynchus and of the family Oligacanthorhynchidae as a whole.
我们对大约 240 年前首次描述的古老棘头虫 Macracanthorhynchus hirudinaceus（Pallas，1781）Travassos，1917 进行了新的形态学观察，这些观察结果以前没有报道过。我们的标本是 2005 年在乌克兰从野猪（Sus scrofa Linn.）中采集的。我们提供了与来自乌克兰、苏联、欧洲、巴西和美国的其他种群的比较形态计量学数据。我们从乌克兰获得的标本的躯干最短（110-120 毫米长），钩子最长最粗，第三只钩子最大，卵最大，吻部比长更宽。我们首次使用扫描电子显微镜记录了吻部、顶端器官、钩子、钩根、感觉孔、微孔和卵的形态。我们还首次使用能量色散 X 射线分析对钩子和卵进行了化学分析，讨论了它们的微孔，并基于欧洲种群的 18S rDNA 提供了一个新的分子谱。钩尖的边缘特征是高水平的钙和磷，但硫的高水平主要存在于卵的皮质层中。从一只成年 M. hirudinaceus 标本中获得了一个新的部分 18S rDNA 序列（482 个核苷酸长度）。我们展示了第一个从欧洲获得的这种世界性棘头虫的 18S rDNA 公布序列。扩增区域对应于小亚基核糖体核糖核酸基因的近似中间区域，该基因的长度约为 1800 个核苷酸。鉴于 Macracanthorhynchus 物种和整个 Oligacanthorhynchidae 家族的遗传信息极其稀缺，这一分子贡献尤为宝贵。
