A spider mating plug: origin and constraints of production

Abstract

Males can increase their reproductive success by mechanically hindering females to mate with subsequent males. Research on mating plugs so far has focused on the fitness consequences and demonstrated that plug size can strongly determine its efficacy. Here, we explore: (1) the site of plug production in the erigonine spider Oedothorax retusus; and (2) whether males are limited in the production of plug material when mating with three females in succession. Micro‐computed tomography, histological and ultrastructural sections demonstrate that the plug material is produced in a massive gland inside the sperm transfer organs of the male, the pedipalps. The glandular lumen is connected with the tube‐like spermophore almost at its blind end. Probably, a reservoir of plug material is built up at the end of the spermophore and released after sperm transfer onto the female genital opening. Since not all males applied a large plug during their first mating, there was no significant decline in plug size over the course of the three successive matings. However, the size of the first plug significantly affected the size of the following plug. We discuss these findings in the light of plug limitation and mate choice. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 345–354.

Paired and complex copulatory organs: do they really impede flexible use?

“…Moreover, contralaterally inserting O. retusus males were able to produce mating plugs with no overt difference in terms of position and appearance of the plug compared with ipsilateral matings. Because plug material is placed onto the genital opening only after sperm transfer (Uhl et al ., ), a normal plug deposition corroborates that sperm transfer had taken place. When two males use opposite copulatory ducts, each male sires 50% of the offspring on average (Kunz et al ., ).…”

Revalidation of Acanthinozodium Denis, 1966 with description of three new species and discovery of a remarkable male palpal character (Araneae, Zodariidae)

“…In the latter case the plug has to be produced and introduced into the epigyne copulatory tract after sperm transfer . This type of glands was well documented by Uhl et al (2014) for Oedothorax retusus (Westring, 1851). Its efficiency is fairly high , but depends on the size and the time it takes to harden.…”

Mating plugs and sexual cannibalism in the Colombian orb‐web spiderLeucauge mariana

“…Male arthropods could contribute with plug substance through components produced in their reproductive tract tissues only during mating or even at certain moments of mating; these substances can vary widely between species (Avila et al., ). For instance, in some mosquitoes (Giglioli & Mason, ) and spiders such as Theridion varians (Knoflach, ), Amaurobius fenestralis and Oedothorax retusus (Uhl, Kunz, Vöcking, & Lipke, ), palp glands connected with the spermatophore are responsible for plug production (Michalik & Ramírez, ). It is important to highlight the contribution of both sexes in plug formation in CO pairs, but we cannot confirm if females exert cryptic female choice based on male sexual performance, influencing reproductive processes such as receptivity or filtering males, as occurs in T. varians (Knoflach, ), L. mariana from CR (Aisenberg, ) and L. argyra (Aisenberg & Barrantes, ).…”