Communication via female resistance: Sexual behavioural modulation and mutual mate choice determinants in a scorpion

Abstract

The paradigm of ‘selective females’ and ‘competing males’ has evolved into a multifactorial interpretation of reproductive decisions, which can lead to prudence in reproductive efforts and adjustability in mate selectivity patterns. In mutual mate choice scenarios, sexual selection may act on the same or different male and female traits, with both sexes potentially assessing the quality of their partner. Meanwhile, during courtship, there is an exchange of signals that may influence mate choice patterns, establishing a sexual dialogue between behaviours and responses of the opposite sex. Scorpions are a fascinating group to study mate choice and behaviour adjustability because both sexes undergo substantial costs during mating and exhibit a wide range of elaborate behaviours during courtship. Here, we investigated the occurrence of mutual mate choice in a scorpion species for the first time, Urophonius achalensis, which is characterized by monandrous females (with genital plugs) and polygynous males. We expected a mutual mate choice scenario in this scorpion species, where both sexes are selective according to the quality of potential mates, preferring individuals of higher body condition and females without plugs in the case of males. In addition, we expected a sexual dialogue during courtship involving adjustability between male behaviours and female responses, rather than a coercive–aggressive scenario. During this dialogue, female resistance response operates as a screening mechanism for male stimulation/ appeasement behaviours. Our results indicate the presence of mutual mate choice in U. achalensis, where female mating status influenced the initial sexual selectivity of both sexes and where male body condition affected female selectivity. We observed behavioural adjustability in both sexes influenced by their own quality and that of their partner, which could be considered a form of sexual dialogue during courtship. This research highlights the value of detailed studies that examine the interplay between behaviours and responses in courtship and contributes to the field of sexual communication and mate choice in scorpions.