Novelty and emergent patterns in sperm: morphological diversity and evolution of spermatozoa and sperm conjugation in ground beetles (Coleoptera: Carabidae)

The beetle family Carabidae, with about 40,000 species, exhibits enough diversity in sperm structure and behavior to be an excellent model system for studying patterns and processes of sperm evolution. We explore their potential, documenting sperm form in 177 species of ground beetles using light microscopy and collecting data on 1 qualitative and 7 quantitative sperm phenotypic traits. Our sampling captures 61% of the tribal-level diversity of ground beetles. These data highlight the notable morphological diversity of sperm in ground beetles and suggest that sperm in the group have dynamic evolutionary histories with much morphological innovation and convergence. Sperm vary among species in total length (48–3,400mm), head length (0.5–270mm), and head width (0.2–6.3mm). Most ground beetles make sperm with heads that are indistinct from the flagella at the gross morphological level. However, some or all Omophron,Trachypachus, and Dyschiriini make broad-headed sperm that show morphologica..., These data include sperm data recorded for 177 species of the beetle family Carabidae, trees dervied from a low-resolution phylogeny of the group, R scripts and data, and online supporting information.

The sperm data was collected from live beetles using light microscopy and image analysis. The trees were derived from the literature and software programs designed for evolutionary analyses (Mesquite and R).

The data were analyzed using a comparative phylogenetic framework using various R packages.
, Supplemental figure

Figure S1 SuppInfo.pdf (a sperm conjugate morphospace for 55 species of ground beetles showing trait loadings for PC1 and PC2)

 

Media

16 movies of carabid sperm of 8 different species viewed in saline on slides

 

Methods S1 SuppInfo.docx

Supplemental methods describing additional details of our methods for sperm data collection

 

R data

Various data files used for comparative analyses in R

1000trees.phy (1000 fully dichotomous random resolutions of our low-resolution phylogeny of Carabidae in phylip format)
colors.txt (a text file with discrete conjugation type data for carabid beetles for use in plotting)
ConjugateDataCarabidR.txt (a text file containing continouous trait data for our studied conjugate traits across carabid beetles)
discretetraitsRdata.txt (a text file containing discrete character data for carabid beetles)
JustSpermDataCarabidR.txt (a text file containing continuous trait data for our studied sperm traits acr...,