DOI: 10.5061/dryad.3ffbg79x4
title: Data from: Genetic and environmental (co)variation of egg size, fecundity, and growth traits in Arctic charr

description: Egg size and fecundity are both positively associated with maternal
 reproductive success, yet maternal resource limitations result in a
 trade-off between these two traits. Exploring this trade-off, the extent
 of genetic and environmental influences on egg size and fecundity, and of
 correlations between these and other traits, and thus the effects acting
 within vs. among generations, is therefore a central goal in both
 evolutionary ecology and selective breeding. Using multi-generational
 captive Arctic charr (Salvelinus alpinus) records, we quantified genetic
 and environmental effects on, and correlations between, egg size and
 fecundity, body size (a proxy for growth) and condition prior to
 maturation, and body size at maturation. We estimated that genetic
 contributions to variation in egg size and fecundity are moderate to high.
 Egg size and fecundity do not significantly correlate at the genetic level
 but do correlate negatively at the environmental level. Growth prior to
 maturation and size at maturation are positively correlated with fecundity
 and egg size at the phenotypic level. Genetic correlations with growth are
 positive for both egg size and fecundity, but weaker for egg size.
 Contrarily, the environmental correlations with growth are of the opposite
 sign, also weaker for egg size, and increasing growth leads to decreasing
 egg size but increasing fecundity. Consequently, reproductive success can
 be optimised across generations via independent selection responses of egg
 size or fecundity and by correlated selection responses with body size.
 Ultimately, the egg size-fecundity resource trade-off in Arctic charr is
 resolved via growth-controlled phenotypic plasticity acting within
 generations.
description: # Genetic and environmental (co)variation of egg size, fecundity, and
 growth traits in Arctic charr Egg size and fecundity both enhance
 reproductive success but are limited by a trade-off. Using
 multi-generational Arctic charr data, we found moderate-to-high genetic
 effects, with no genetic correlation but a negative environmental
 correlation between egg size and fecundity. Growth traits correlated
 positively with each trait phenotypically, though genetic and
 environmental correlations differed. This suggests the trade-off is
 resolved by growth-mediated plasticity within generations, enabling
 flexible selection on reproductive traits. #### Description of the data
 and file structure The dataset consists of a Data.csv which has the
 following variables: * Cohort: Cohort ID that corresponds to the year of
 fertilisation - Number: Individual ID * Dam: Dam ID - Sire: Sire ID *
 Cohort.Sib: Family ID - YearStationID: Common environment ID that
 corresponds to the growing environment until age 2 years * BreederAge.y:
 Age in years of the individual when being sexually mature - Length2.mm:
 Fork length in mm of the individual at the age of 2 years * Mass2.g: Total
 wet mass in g of the individual at the age of 2 years - EggNumberTotal.n:
 Total number of eggs stripped of the (female) individual at BreederAge.y
 and estimated from total egg batch mass * EyedEggMass.mg: Average egg mass
 (at the eyed stage) in mg of the (female) individual at BreederAge.y from
 an average of 25 eggs - StrippedMass.g: Total wet mass of the (female)
 individual after egg stripping at BreederAge.y Missing data represented as
 NA