Purpose】The first segment of the springtail's abdomen features a unique ventral tube structure known as the collophore. For a long time, the academic community has widely believed that reversible vesicles are present inside the ventral tube, which serve functions such as water absorption and body cleaning. However, to date, there have been no clear imaging reports on the specific organs within the abdominal canal of springtails.【Method】To unravel this mystery, we selected S. viridis as our research subject and collected over 13,000 springtails (average length 1mm) from the field over 16 years. Through microdissection of the abdomen of more than 9,700 springtails, we obtained 4 complete organ slide samples and 616 local organ slide samples. We accumulated a large amount of image data using optical microscopy combined with mobile phone cameras.【Result】A large amount of imaging data confirms that there are two retractable tentacles inside the ventral tube of the springtail, with a large number of tiny suction cups distributed on the surface; And connect two pairs of muscle rods with a series of valves distributed. We believe that this is a specialized new type of organ.
【Conclusion】A large number of anatomical observations and imaging data have confirmed the existence of this specialized new organ. The retractable tentacle tube forms the main system for absorbing liquid and providing suction cup negative pressure with many small suction cups. The two pairs of muscle rods are the power source and transport channel for the retractable tentacle. This discovery provides morphological evidence for the multiple functions of the abdominal duct, and provides a reference for the control of springtail pests and the study of arthropod evolution.
