Micro-CT was performed to a juvenile polychaete (Eunice sp.). This specimen was fixed and preserved in 96% ethanol. Specimen was stained in 1% Iodine solution in 96% ethanol for 24 hours. Scan was performed with a Skyscan 1172 at a voltage of 59kV and 167μΑ without filter for a full rotation of 360o . This specimen was scanned at the highest camera resolution with an exposure time of 1835ms. This scan was performed for a visualization of chaetae (http://zookeys.pensoft.net/articles.php?id=3650). Specimen was provided and scanned by Sarah Faulwetter. The original dataset is available in https://datadryad.org/resource/doi:10.5061/dryad.84m54.