Here you can access the SpermTree database with a downloadable data file (.xlsx) and reference file (.docx). The data file contains sperm length and fertilization mode as well as taxonomic information for each species from Kahrl et al. 2021. 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.