Form-assortative mating behaviors of individuals from parasitic and non-parasitic populations of Arctic lamprey (Lethenteron camtschaticum)

Evolutionary theory predicts that assortative mating is crucial for sympatric speciation by generating reproductive isolation between diverging populations. Here, we investigate the potential of form-assortative mating, an assumed mating pattern in lampreys, for sympatric speciation. By continuously recording mating activity between anadromous and freshwater-resident forms of L. camtschaticum that greatly differ in body size, we show that lampreys tend to mate with individuals of similar size in experimental conditions. However, we highlight that this pattern does not result from a choice of same-form partner but is the result of the simultaneous action of a preference of males – whatever their size – for large anadromous females, a higher competitive ability of aggressive males and physical constraints on heteroform pairs. Moreover, we do not advocate that sympatric speciation, as the sole consequence of form-assortative mating through sexual selection, is a plausible mechanism for the..., We provide the raw data files (\"Ind.xlsx\",\"data_pair.xlsx\") and script file (\"BE_script.R\") to process the raw data, make plots, and run the statistics., , # Data from: Form-assortative mating behaviors of individuals from parasitic and non-parasitic populations of Arctic lamprey (Lethenteron camtschaticum)

[https://doi.org/10.5061/dryad.931zcrjvg](https://doi.org/10.5061/dryad.931zcrjvg)

## Description of the data and file structure

R script, and data used to run the plots and analysis presented in: Daupagne, L., Furusawa, C., Mieda, H., Kishida, O., Lasne, E., Tentelier, C. & I. Koizumi. Form-assortative mating behaviors of individuals from parasitic and non-parasitic populations of Arctic lamprey (*Lethenteron camtschaticum*). *Behavioral Ecology*.

### Files and variables

#### File: BE\_script.R

**Description:** the only file that you need to open. Loads datasets and formats data for running the analysis and plotting figures. All of the files in must be within your working directory for the analysis to work.

#### File: Ind.xlsx

**Description:** file containing data on individual ID

**Variables:** Subject= code used to ident...