DOI: 10.5061/dryad.6djh9w1bp
title: Genetic variation in age-dependent attractiveness in a fish with a mixed mating system

description: Reproductive senescence is common in many taxa and females often show a
 predictable decline in fecundity after maturity. Attending to these
 age-dependent cues in female fecundity could help males make optimal mate
 choice decisions. In this study, we examined reproductive senescence and
 male mate choice in the androdioecious mangrove rivulus (Kryptolebias
 marmoratus) where self-fertilizing hermaphrodites exist with rare males
 and where generations of self-fertilization result in genetically distinct
 lineages. Hermaphrodites showed a strong decline in fecundity as they aged
 and genetic lineages varied in their fecundity both at young and old ages.
 Surprisingly, when given a simultaneous choice between genetically
 identical old and young hermaphrodites, and with access to both visual and
 olfactory cues, males did not simply prefer younger hermaphrodites.
 Instead, male preference for younger vs older partners depended on the
 genetic lineage of the partners, resulting in a strong genotype x age
 interaction. For some genetic lineages, hermaphrodites were more
 attractive to males when younger, but for other genetic lineages,
 hermaphrodites were more attractive when older. Our results suggest that
 genetic identity of the partner is key to how males weigh age-dependent
 changes in fecundity, and that males are able to assess genetic variation
 in attractiveness over a partner’s reproductive lifespan. Exploring how
 gamete viability and outcrossing is affected by age across genetic
 lineages could help us further understand these flexible male
 preferences.  
description: # Genetic variation in age-dependent attractiveness in a fish with a mixed
 mating system
 [https://doi.org/10.5061/dryad.6djh9w1bp](https://doi.org/10.5061/dryad.6djh9w1bp) ## Description of the data and file structure **PART 1:** Fecundity assay We measured the number of embryos produced by younger and older hermaphrodites across 4 different lineages **PART 2:** Male preference assays We measured how much time single males spent with simultaneously presented younger and older hermaphrodites across 4 different lineages ### Files and variables #### **PART 1:** Fecundity assay file 1A: embryo_data.csv columns: A. lineage = the particular genetic lineage the focal fish belongs to ( BP16, BP21, CROC27, or  CROC31) B. generation = the generation in the lab that the focal fish belongs to (eg. F8 to F10) C. ID = individual ID number for the focal hermaphrodite fish D. days_old = the age of the focal fish in days (embryo collection minus birthdate) E. age = category of age (young = ~250 days old; old = ~500 days old) F. embryos = number of embryos collected over 3 weeks (2 collections between 5/1/23 and 5/11/23) **PART 2:** Male preference assays file 2A: choice_data_wide.csv columns: A. test_date = date of trial (month.day.year) B. test_time = time of day of trial C. trial_number = whether it was the male’s first or second time being tested D. male_letter = random letter given to the 20 males (A to R) E. male_ID = individual ID number for the focal male F. male_clone = the particular genetic lineage the focal male belongs to (BWN3, BWS34, BWS38, BP11. BP13) G.  male_birthdate = birthdate (month.day.year) H. male_days_old = the age of the focal male in days at the time of testing (test-date minus birthdate) I. male_SL = the standard length of the focal male at the end of all trials (in mm) J. old_side = tank side that old partner was placed (Right vs Left) based on coin flip K. herm_clone = the particular genetic lineage that both hermaphrodite partners belong to (BP16, BP21, CROC27, CROC31) L. old_ID = individual ID number for the old hermaphrodite partner M. old_birthdate = birthdate (month.day.year) of the old hermaphrodite partner N. old_days_old = the age of the old hermaphrodite partner in days at the time of testing (test-date minus birthdate) O. old_SL = the standard length of the old hermaphrodite partner at the time of testing (in mm) P. old_total_time_sec = the total time (in seconds) spent with the old hermaphrodite partner during the trial Q. yng_ID = individual ID number for the old hermaphrodite partner R. yng_birthdate = birthdate (month.day.year) of the old hermaphrodite partner S. yng_days_old = the age of the old hermaphrodite partner in days at the time of testing (test-date minus birthdate) T. yng_SL = the standard length of the old hermaphrodite partner at the time of testing (in mm) U. yng_total_time_sec = the total time (in seconds) spent with the old hermaphrodite partner during the trial V. total_pref_time = the total time (in seconds) spent with any hermaphrodite partner during the trial (young time + old time) W. prop_w_old = proportion of the total preference time spent with the old hermaphrodite partner (old time / (young + old) ) X. diff_old_minus_young = difference in time spent with old and young hermaphrodite partners (old time - young time) file 2B: choice_data_long.csv columns: A. test_date = date of trial (month.day.year) B. test_time = time of day of trial C. trial = the preference trial number (#1-40) D. trial_number = whether it was the male’s first or second time being tested E. male_letter = random letter given to the 20 males (A to R) F. male_ID = individual ID number for the focal male G. male_clone = the particular genetic lineage the focal male belongs to (BWN3, BWS34, BWS38, BP11. BP13) H. male_days_old = the age of the focal male in days at the time of testing (test-date minus birthdate) I. male_SL = the standard length of the focal male at the end of all trials (in mm) J. old_side = tank side that old partner was placed (Right vs Left) based on coin flip K. herm_clone = the particular genetic lineage that both hermaphrodite partners belong to (BP16, BP21, CROC27, CROC31) L. partner_age = category of age (young = ~250 days old; old = ~470 days old) M. partner_ID = individual ID number for the hermaphrodite partner N. partner_days_old = the age of the hermaphrodite partner in days at the time of testing (test-date minus birthdate) O. partner_SL = the standard length of the hermaphrodite partner at the time of testing (in mm) P. partner_first_approach_sec = the time to first approach the partner (in seconds); "." means the partner was not approached during the trial (resulting in zero seconds spent associating with that partner) Q. partner_total_time_sec = the total time (in seconds) spent with the hermaphrodite partner during the trial file 2C: male_consistency.csv columns: A. male_letter = random letter given to the 20 males (A to R) B. male_clone = the particular genetic lineage the focal male belongs to (BWN3, BWS34, BWS38, BP11, BP13) C. male_SL = the standard length of the focal male at the end of all trials (in mm) D. t1prop_w_old = proportion of the total preference time spent with the old hermaphrodite partner (old time / (young + old) ) at the male’s first trial E. t1diff_old_minus_yng = difference in time spent with old and young hermaphrodite partners (old time - young time) at the male’s first trial F. t2prop_w_old = proportion of the total preference time spent with the old hermaphrodite partner (old time / (young + old) ) at the male’s second trial G. t2diff_old_minus_yng = difference in time spent with old and young hermaphrodite partners (old time - young time) at the male’s second trial ## Code/software RStudio; code is uploaded.