When rivals are absent: Male aggression towards females in bluefin killifish

The process of obtaining mates, mating, and (potentially) caring for offspring is costly. While there are inherent costs to reproduction, behavioral interactions among individuals are often the primary drivers of reproductive costs. Males frequently compete for territories, and females may compete for food or males; males often harass females.  Here, we sought to determine whether reproductive costs were primarily due to male/male competition, female/female competition, or male/female interactions in the bluefin killifish. In this species, males guard small spawning territories where females visit them daily to spawn. To manipulate the potential for male and female competition and male/female interactions, we altered the sex ratio and density of each sex across four treatments (1 male: 1 female, 1 male : 3 females, 3 males: 1 female, 3 males: 3 females). Female mortality was higher than male mortality. Surprisingly, female mortality and male aggressive behaviors towards females (i...., This experiment aimed to assay the levels of aggression in male and female bluefin killifish (both within and between the sexes) and to determine the extent to which aggression led to detrimental effects on survival. We manipulated the sex ratio and density of bluefin killifish in 110-liter tanks and observed behavior and survival. We manipulated sex ratios and density to create treatments where competition and aggression were likely to differ between males and females. We created a treatment with a male-biased sex ratio (3 males: 1 female) and a female-biased sex ratio (1 male: 3 females). We also had two controls with an even sex ratio to control for the density of each sex (1 male : 1 female and 3 males : 3 females). Six replicates were performed across the four treatments (24 tanks in total). The experiment was carried out between February 2020 – July 2020. The experimental tanks were initially set up in late February 2020. Due to the COVID-19 pandemic, they remained in those c..., , # When rivals are absent: Male aggression towards females in bluefin killifish

[https://doi.org/10.5061/dryad.wdbrv15z8](https://doi.org/10.5061/dryad.wdbrv15z8)

## Description of the data and file structure

Meta-Data for Data Associated with the Article “When Rivals Are Absent: Male Aggression Towards Females in Bluefin Killifish”

Explanations for the data in the file “mortality_uploaded.csv”.

In this study, we examined the number of males and females that died during the experiment as a function of the different sex ratio and density treatments. We used the following experimental setup – tanks with 1 male: 1 female, 1 male : 3 females, 3 males: 1 female, 3 males: 3 females.

The R script ‘mortality_uploaded.R’ refers to these data.

* Column 1 Treatment – Sex ratio and density treatments - with 1 male: 1 female, 1 male : 3 females, 3 males: 1 female, 3 males: 3 females

- Column 2 Replicate – Replicate number

* Column 3 Tank_no - This is the code that was given to each tank of f...,