How do familiarity and relatedness influence mate choice in Armadillidium vulgare?

Abstract

Mate choice is an important process in sexual selection and usually prevents inbreeding depression in populations. In the terrestrial isopod Armadillidium vulgare, the close physical proximity between individuals may increase the risk of reproducing with siblings. Moreover, individuals of this species can be infected with the feminizing bacteria of Wolbachia, which influence male mate choice. However, little is known about the kinship or familiarity assessment of the selected partner that occurs when a male can choose between females with or without Wolbachia. To investigate the potential mechanisms leading to mate choice and the potential impact of the parasite, we performed behavioral choice tests on males where they could choose between sibling vs. nonsibling females, familiar vs. unfamiliar females, and sibling familiar vs. unfamiliar nonsibling females. To investigate the costs of inbreeding, we compared the reproductive success of both sibling and nonsibling mates. Our results revealed that male copulation attempts were higher for familiar females and for nonsibling females when both females were Wolbachia-infected, but the duration was longer when both females were Wolbachia-free. When males mated with a sibling female, their fecundity was severely decreased, consistent with inbreeding depression. Overall, we observed copulations with all types of females and demonstrated discrimination capacities and potential preferences. We highlight the complexity of the tradeoff between kinship, familiarity and parasite transmission assessment for mate choice.

Wolbachia promotes successful sex with siblings in the parasitoid Habrobracon hebetor

“…In Drosophila simulans , for example, it has been reported that Wolbachia ‐infected males mate at a higher rate than uninfected males 38 . Higher male copulation rate with Wolbachia ‐infected females has also been demonstrated in the terrestrial isopod Armadillidium vulgare 39 . Moreover, Wolbachia infection has been shown to reduce sperm competitive ability in D. simulans 40 .…”

Brothers are better than nothing: first report of incestuous mating and inbreeding depression in a freshwater decapod crustacean

“…penaeid shrimps) (Moss et al, 2008;De los Ríos-Pérez et al, 2017), and low-fecundity crustaceans with direct development (i.e. terrestrial isopods) (Fortin et al, 2018). Unlike these data, fecundity usually declines in inbred clutches of diverse invertebrate species, including the cockroach Blattella germanica (Lihoreau et al, 2007), the bulb mite Rhizoglyphus robini (Radwan, 2003) and the wolf spider Pardosa astrigera (Chen et al, 2017).…”

“…Some of these traits have been shown to decrease due to inbreeding in many vertebrate species, such as flycatchers (Kruuk et al, 2002), guppies (Pitcher et al, 2008) and lemurs (Charpentier et al, 2008). Negative effects of inbreeding have also been reported for various traits in invertebrate groups, such as spiders (Bilde et al, 2007), cockroaches (Lihoreau et al, 2007), sea urchins (Anderson and Hedgecock, 2010), scallops (Zheng et al, 2012), beetles (Liu et al, 2014), and terrestrial isopods (Fortin et al, 2018). However, this phenomenon is poorly documented in aquatic crustaceans, with few studies showing lower survival, growth, or resistance to diseases in inbred progenies of some copepod, penaeid shrimp and crab species (Palmer and Edmands, 2000;Keys et al, 2004;Moss et al, 2007;Luo et al, 2014;Gao et al, 2015).…”

Male antennae of Armadillidium vulgare discriminate Wolbachia-infected females

“…Wb females also show a decrease in their mating success [31,37,38]; however, the cause of this decrease is still unknown. Two main hypotheses can be formulated: (i) In the short range, the chemical differences in cuticular profiles between Wb females and Wb-free females may allow males to assess their respective health status [12], helping them properly orient their sexual behaviour towards uninfected females.…”