Sexual dimorphism and patterns of sexual behavior in Lustrochernes argentinus (Pseudoscorpiones: Chernetidae)

Abstract

Sexual dimorphism between females and males can sometimes be related to particular mating behaviors. In pseudoscorpions, very little is known about the relationship between sexual size dimorphism (SSD) and reproductive behavior. This paper describes sexual dimorphism and the mating behavior patterns of Lustrochernes argentinus (Thorell, 1877), a Neotropical species of Cheliferoidea. We measured different body structures and appendages of 14 individuals of each sex, with the values compared with a T-test. We also analyzed the sexual behavior repertoire occurring during mating between nine couples. We found SSD for several structures: the fixed and movable finger width, and the angle between IV coxae are larger in females, in contrast with the gap between fingers which is bigger in males. The analysis of sexual behavior patterns in this species showed that the reproductive behavioral repertoire is structured in three phases: Phase I (examination), Phase II (spermatophore deposition) and Phase III (sperm transfer) with a mean duration of 2.2 min, 5 min, and 7.5 min, respectively. Some structures that showed SSD, and also the composition and duration of different behavioral phases, are different from those of other species of the family Chernetidae. We discuss the results based on current knowledge in pseudoscorpion biology with prospects of further studies studying sexual selection.

Mating behavior of Dactylochelifer latreillii latreillii (Pseudoscorpiones: Cheliferidae): A quantitative study

“…The term ''behavioral unit'' was used, similarly to other recent publications (Stanley et al 2016;Palen-Pietri et al 2019) on arachnid mating behavior. Major behavioral units were named according to existing terms from Weygoldt (1969); the terminology of genital structures follows Legg (1974a, b).…”

“…In the past decades, publications on mating behavior of pseudoscorpions were almost exclusively dedicated to species of the cheliferoid family Chernetidae (Zeh & Zeh 1992, 1997Andrade & Gnaspini 2003;Palen-Pietri et al 2019), whereas mating in Cheliferidae has not been studied recently. Quantitative studies on mating, as already available for some other arachnid groups (e.g., Girard et al 2011;Fowler-Finn et al 2019), are scarce for pseudoscorpions (Palen-Pietri et al 2019) and particularly missing in Cheliferidae.…”

“…In the past decades, publications on mating behavior of pseudoscorpions were almost exclusively dedicated to species of the cheliferoid family Chernetidae (Zeh & Zeh 1992, 1997Andrade & Gnaspini 2003;Palen-Pietri et al 2019), whereas mating in Cheliferidae has not been studied recently. Quantitative studies on mating, as already available for some other arachnid groups (e.g., Girard et al 2011;Fowler-Finn et al 2019), are scarce for pseudoscorpions (Palen-Pietri et al 2019) and particularly missing in Cheliferidae. Although some authors try to give a comparative overview on mating phase duration of certain pseudoscorpion groups (Weygoldt 1966(Weygoldt , 1969(Weygoldt , 1970Andrade & Gnaspini 2003), the majority of data is restricted to scattered time indications for behavioral steps without any remarks on sample size and data range (Kew 1912;Vachon 1938;Weygoldt 1966Weygoldt , 1969Weygoldt , 1970Boissin 1973).…”

Gut parasites infection increases mate rejection in a species with indirect sperm transfer

“…Videos were analyzed using JWatcher software (Blumstein & Daniel, 2007) to identify the main behaviors. The variables considered were: (1) rejection by female (the female permanently interrupts pedipalp grasping when the male is depositing the spermatophore), (2) rejection by male (the male permanently interrupts contact with the female after briefly grasping her pedipalps during phase I), and (3) occurrence of sperm uptake (the female presses her genital opening over the spermatophore taking the sperm packet); the emptied spermatophore is easily distinguishable (Palen-Pietri et al, 2019).…”

“…A species where intersexual contact exists during mating is Lustrochernes argentinus (Thorell), a neotropical pseudoscorpion that belongs to the Chernetidae family. The courtship of this species has a duration of approximately 7 min, and it is divided into three phases: (i) examination (2 min), where individuals assess their potential partner while grasping each other's pedipalps, (ii) spermatophore deposition (5 min), where stimulation behaviors such as rubbing chelicera occur, and (iii) sperm transfer (10 s), where the female actively performs the sperm uptake from the fresh spermatophore (Palen‐Pietri et al, 2019). During the analysis of L. argentinus , we observed that, in some cases, both males and females could choose not to mate with the individual present in the arena suggesting mutual mate choice.…”