Producing offspring in Armadillidium vulgare: Effects of genetic diversity and inbreeding

Abstract

Genetic diversity is known to be correlated to fitness traits, and inbred individuals often display lower values for life history traits. In this study, we attempt to quantify how inbreeding affects such traits in the terrestrial isopod Armadillidium vulgare by performing inbred and non-inbred crosses under laboratory conditions. We estimated genetic characteristics of parents and offspring, and related them to fecundity and fertility measures, as well as offspring growth and survival. Our study shows that a decrease in offspring number might result from mortality around birth, but not to changes in fecundity, fertilization rate, or developmental failure between inbred and non-inbred crosses. More heterozygous females tended to be bigger and had a higher fecundity, which could have implications in mate choice. No effect of inbreeding was detected on offspring growth and survival. These results can be related to previously observed effects of genetic characteristics on mating strategies in A. vulgare, and could shed light on mechanisms of inbreeding avoidance in this species.

Deleterious effects of thermal and water stresses on life history and physiology: a case study on woodlouse

“…In parallel, the water stress leads to a decrease in reproductive success, as previously reported in females of Antestiopsis thunbergii (Azrag et al, 2017). In A. vulgare, individual body size is positively correlated with fecundity (Durand et al, 2018;Lawlor, 1976), meaning that the slowdown in growth could explain, at least partly, the decrease in reproductive success for stressed animals compared to non-stressed ones. Concerning the water stress, if the loss of moisture has no detectable effect on woodlouse growth, it causes a decrease in both survival and reproductive success.…”

Reproductive senescence and parental effects in an indeterminate grower

“…Clutch Finally, reproductive senescence can be masked by the selective disappearance of low-quality individuals (Nussey, Coulson, Festa-Bianchet, & Gaillard, 2008). For a given age, larger females produce more offspring in the common woodlouse and body mass is thus generally thought to be a good indicator of individual quality (Durand et al, 2018). We tested for such relationships by modelling the breeding rate as binary data using a generalized linear model (GLM) with maternal mass set as a fixed factor within the young and old mothers separately.…”

“…Offspring develop in this pouch and benefit from a protected environment and nutrients provided by their mother (Surbida & Wright, 2001). As the incubation of the offspring takes place in the marsupium, the size of the females is closely associated with the number of offspring produced (Dangerfield & Hassall, 1992; Durand, Loiseau, Prigot, Braquart‐Varnier, & Beltran‐Bech, 2018; Paris & Pitelka, 1962).…”

Deleterious effects of thermal and water stresses on life history and physiology: a case study on woodlouse

“…In parallel, we observed that the increase in temperature led to a decrease in reproductive success, as previously observed in females of Antestiopsis thunbergii (Azrag et al, 2017). In A. vulgare , the animal size is positively correlated with fecundity (Durand et al, 2018; Lawlor, 1976), meaning that the slowdown in growth could explain, at least partly, the decrease in reproductive success for stressed animals compared to non-stressed ones. Concerning the moisture stress, if the loss of moisture had no detectable effect on woodlouse growth, it caused a decrease in both survival and reproductive success.…”