Florida State Collection of Arthropods, Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Gainesville, Florida, United States of America.
PLoS One. 2022 Feb 25;17(2):e0264358. doi: 10.1371/journal.pone.0264358. eCollection 2022.
It is generally thought that the anterior border of the opisthosoma of acariform mites is delineated by the disjugal furrow, but there is no evidence to support this other than the superficial appearance of tagmosis in some oribatids. It is proposed herein that the disjugal furrow is an apomorphic feature that does not correspond with any segmental borders. Although the disjugal furrow is absent from Proteonematalycus wagneri Kethley, the visible body segments of this species indicate that this furrow, when present, intersects the metapodosoma. Therefore, the disjugal furrow does not delineate the anterior border of the opisthosoma. Instead, this border is between segments D and E (segments VI and VII for all arachnids). This hypothesis can be accommodated by a new model in which the proterosoma warps upwards relative to the main body axis. This model, which is applicable to all Acariformes, if not all arachnids, explains the following phenomena: 1) the location of the gnathosomal neuromeres within the idiosoma; 2) the relatively posterior position of the paired eyes; 3) the shape of the synganglion; 4) the uneven distribution of legs in most species of acariform mites with elongate bodies.
人们通常认为，节肢类螨的后体前缘由离轭沟界定，但除了某些革螨目具有节段性外观的表面现象外，没有证据支持这一点。本文提出，离轭沟是一个特化特征，与任何体节边界都不对应。虽然 Proteonematalycus wagneri Kethley 中没有离轭沟，但该物种的可见体节表明，当存在离轭沟时，它会与后生体相交。因此，离轭沟并不界定后体的前缘。相反，这个边界在 D 节和 E 节之间（对于所有蛛形纲动物来说，是 VI 节和 VII 节）。这个假设可以通过一个新模型来解释，即前体相对于主体轴向上扭曲。这个模型适用于所有节肢类螨，如果不是所有蛛形纲动物的话，它可以解释以下现象：1）口器神经节在体躯内的位置；2）复眼相对靠后的位置；3）交感神经节的形状；4）大多数具有细长身体的节肢类螨的腿不均匀分布。
