bioRxiv preprint doi: https://doi.org/10.1101/809863; this version posted October 21, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Gomez 1 1 Novelty and emergent patterns in sperm: morphological diversity and evolution 2 of spermatozoa and sperm conjugation in ground beetles (Coleoptera: 3 Carabidae) 4 Running title: Diversity and evolution of ground beetle sperm 5 R. Antonio Gomez* & David R. Maddison 6 Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, 7 Corvallis, OR 97333 8 *email of corresponding author:
[email protected] 9 10 1. Abstract 11 The beetle family Carabidae, with about 40,000 species, exhibits enough 12 diversity in sperm structure and behavior to be an excellent model system for 13 studying patterns and processes of sperm evolution. We explore their potential, 14 documenting sperm form in 177 species of ground beetles and collecting data on 1 15 qualitative and 7 quantitative sperm phenotypic traits. Our sampling captures 61% of 16 the tribal-level diversity of ground beetles. These data highlight the notable 17 morphological diversity of sperm in ground beetles and suggest that sperm in the 18 group have dynamic evolutionary histories with much morphological innovation and 19 convergence. Sperm vary among species in total length from 48–3,400μm and in 20 length and width of the sperm head. Most ground beetles make filamentous sperm 21 with visually indistinct heads, but some or all studied members of the genus 22 Omophron, genus Trachypachus, and tribe Dyschiriini make broad-headed sperm that 23 show morphological differences between species.