Patterns of sperm swimming behaviour depend on male mating tactic and spawning environment in chinook salmon

Many species exhibit alternative mating tactics (ARTs), with larger, socially dominant males competing for females and smaller males adopting “sneaker” strategies to exploit fertilisation opportunities without competition or courtship. Females typically prefer larger socially dominant males, but their ability to manipulate mating or fertilisation outcomes is largely unknown. Here, using chinook salmon Oncorhynchus tshawytscha, we ask whether the female’s ovarian fluid (OF) differentially influences the temporal patterns of sperm swimming in ejaculates from non-preferred sneaker (‘parr’) and preferred (dominant) males. We demonstrate that OF improves sperm swimming speed and linearity compared to river water, regardless of male mating tactic, but also report a novel tactic-specific difference in sperm linearity; parr male sperm initially maintain straighter trajectories in river water, compared to dominant males, but then rapidly change to less linear and more circular paths over time. I..., , , # Data from: Patterns of sperm swimming behaviour depend on male mating tactic and spawning environment in chinook salmon

[https://doi.org/10.5061/dryad.3tx95x6r6](https://doi.org/10.5061/dryad.3tx95x6r6)

## Description of the data and file structure

### Raw data

This file contains all of the raw data analysed for this paper.

**Rosengrave_et_data.csv**

This file explains all dataset variables accompanying Patterns of sperm swimming behaviour depending on male mating tactics and spawning environment in chinook salmon.

**Dataset**: Rosengrave_et_al_data.CSV

The file includes the following columns standard to the format:

**Column Entry Unit Explanation**

A **Sample** Unique ID for each CASA capture
B **ID** ID of milt subsample
C **Male** Focal male ID
D **Tactic** Alternative reproductive tactic of the focal male. H = large 2-year-old male, S = parr (sneaker) male
E **Treatment** Medium of sperm activation. RW = river water, OV = ovarian fluid
F T**ime seconds **Seconds Time...,