Here you can access the SpermTree database with a downloadable data file (.xlsx). The SpermTree data file contains sperm head, midpiece, principle piece, flagellum, total length, fertilization mode, full references as well as taxonomic information for each species from Kahrl et al. 2021 and from Fitzpatrick et al. 2022. We hope that this database can continue to grow as more data on sperm morphology and fertilization mode are published. We will update the files semi-regularly with newly published data. If you would like to add your data to the SpermTree, please visit the ‘Contribute‘ page for more information.