Research Computing & Instrumentation, University of New Hampshire, Rudman Hall, 46 College Road, Durham, NH 03824, USA.
Arthropod Struct Dev. 2013 Sep;42(5):407-23. doi: 10.1016/j.asd.2013.04.003. Epub 2013 May 13.
Spinnerets from Phobetinus sagittifer and an undescribed Phobetinus species were examined by scanning electron microscopy to gain a better understanding of this genus' relationships to other genera in the family Mimetidae. Consistent with placement of Phobetinus in Mimetinae, females possessed two synapomorphies of this subfamily; enlarged cylindrical silk gland spigots with domed shafts and a single cylindrical spigot per posterior lateral spinneret (PLS). Spinning field features overall suggest Phobetinus is most closely related to Mimetus, followed by Australomimetus, then Ero. A possible synapomorphy of a clade including Mimetus and Phobetinus is a pair of modified piriform silk gland spigots on each anterior lateral spinneret of adult males located adjacent to the secondary major ampullate silk gland tartipore. These spigots were present in P. sagittifer; however, similarly positioned spigots in the undescribed species were not obviously modified (i.e., wider or with larger openings relative to the other piriform spigots). Close affinity to Mimetus was also indicated by tartipore-accommodated PLS aciniform silk glands in both Phobetinus species. These have been consistently observed in Mimetus, but not in Australomimetus or Ero. Somatic and genitalic drawings of P. sagittifer are provided to aid identification and similarities are noted between male pedipalps of Mimetus and Phobetinus.
利用扫描电子显微镜对来自 Phobetinus sagittifer 和一个未描述的 Phobetinus 物种的纺器进行了检查，以便更好地了解该属与 Mimetiidae 科中其他属的关系。与将 Phobetinus 置于 Mimetiinae 一致，雌性具有该亚科的两个共形特征；扩大的圆柱形丝腺喷口，轴呈圆顶状，每个后外侧纺器（PLS）只有一个圆柱形喷口。整体纺丝场特征表明，Phobetinus 与 Mimetus 关系最为密切，其次是 Australomimetus，然后是 Ero。包括 Mimetus 和 Phobetinus 的一个分支的可能共形特征是，每对前外侧纺器上都有一对位于次级主要膨体丝腺 tartipore 附近的改良梨形丝腺喷口。这些喷口存在于 P. sagittifer 中；然而，在未描述的物种中，类似位置的喷口并没有明显的改变（即相对于其他梨形喷口更宽或开口更大）。Mimetus 的密切亲缘关系也表现在 Phobetinus 两个物种的 tartipore 容纳的 PLS 棒状丝腺中。这些在 Mimetus 中一直观察到，但在 Australomimetus 或 Ero 中没有观察到。提供了 P. sagittifer 的躯体和生殖器绘图，以帮助识别，并注意到 Mimetus 和 Phobetinus 的雄性触肢的相似之处。
