Monod Lionel, Cauwet Lucie, González-Santillán Edmundo, Huber Siegfried
Département des arthropodes et d'entomologie I, Muséum d'histoire naturelle, Route de Malagnou 1, 1208 Genève, Switzerland.
Instituto de Biotecnología, UNAM, Avenida Universidad 2001, Colonia Chamilpa C.P., 62210 Cuernavaca, Morelos México.
Front Zool. 2017 Nov 22;14:51. doi: 10.1186/s12983-017-0231-z. eCollection 2017.
Insemination in scorpions is carried out by means of a partly sclerotized structure, the spermatophore, which is composed of two separate halves, the hemispermatophores. In most genera these reproductive structures can be used to differentiate species. However, many taxa such as the genus and the family Diplocentridae lack the morphological diversity observed in the copulatory organs of many other arthropods, rendering them useless for species level taxonomy. Such structural stasis, however, suggests that hemispermatophores have evolved relatively slowly and may thus provide a stronger phylogenetic signal for recognizing supra-generic ranks than previously thought. Based on the postulate that the phenotypic stability observed in some groups is the consequence of functional constraint, the most comprehensive comparative study of the male sexual apparatus to date was conducted for a complete reassessment of the morphology, phylogenetic value and hypotheses of homology of these structures.
Hemispermatophores, pre- and post-insemination spermatophores, as well as the inherent mechanisms of insemination, were studied across the whole order, allowing the recognition and description of a series of five basic bauplans for the capsular region. For the most part, these patterns appear to be consistent within each major taxonomic group, but several cases of incongruence between spermatophore morphology and taxonomy raises questions about the monophyly of some clades. The Bothriuridae are traditionally regarded as a basal scorpionoid family. However, except for the genus , bothriurid hemispermatophores and spermatophores are morphologically more similar to those of the Chactoidea than to those of scorpionoids. On the other hand, the male copulatory structures of the hormurid clade ( ()) are more akin to those of Diplocentridae and Heteroscorpionidae than to those of other hormurids.
Spermatophore capsular patterns appears to be congruent with a recent phylogeny of the order Scorpiones based on phylogenomic data that placed Bothriuridae outside of Scorpionoidea and outside of Hormuridae, in contradicton with earlier phylogenetic reconstructions based on morphology. This raises questions about the potential use of functionally constrained traits to assess the reliability of contradicting phylogenetic hypotheses and emphasizes the need for a thorough reassessment of the scorpion phylogenetic relationships.
蝎子的受精是通过一个部分硬化的结构——精荚来完成的，精荚由两个分开的部分组成，即半精荚。在大多数属中，这些生殖结构可用于区分物种。然而，许多类群，如 属和双棘蝎科，缺乏在许多其他节肢动物交配器官中观察到的形态多样性，这使得它们在物种水平分类中毫无用处。然而，这种结构上的停滞表明半精荚的进化相对缓慢，因此可能为识别超属等级提供比以前认为更强的系统发育信号。基于某些群体中观察到的表型稳定性是功能限制的结果这一假设，迄今为止对雄性性器官进行了最全面的比较研究，以重新评估这些结构的形态、系统发育价值和同源性假设。
对整个目范围内的半精荚、受精前和受精后的精荚以及受精的内在机制进行了研究，从而识别并描述了囊状区域的一系列五种基本结构模式。在很大程度上，这些模式在每个主要分类群中似乎是一致的，但精荚形态与分类学之间的一些不一致情况引发了对某些类群单系性的质疑。瘤尾蝎科传统上被视为一个基部蝎类家族。然而，除了 属外，瘤尾蝎科的半精荚和精荚在形态上与裂盾蝎超科的更相似，而不是与蝎类的相似。另一方面，瘤蝎类分支（ （ ））的雄性交配结构与双棘蝎科和异蝎科的更相似，而不是与其他瘤蝎科的相似。
精荚囊状模式似乎与基于系统基因组数据的蝎目最新系统发育一致，该数据将瘤尾蝎科置于蝎亚目之外，将 置于瘤蝎科之外，这与早期基于形态学的系统发育重建相矛盾。这就提出了关于利用功能受限性状来评估相互矛盾的系统发育假设可靠性的潜在用途的问题，并强调了彻底重新评估蝎子系统发育关系的必要性。
