Seminar this Monday February 12: Mating plugs in spiders: deposition, removal and potential for female control

We are happy to invite you to a guest seminar Monday February 12th 2018 at 14:00 EEB Seminar room

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Mating plugs in spiders: deposition, removal and potential for female control

Dr. Lenka Sentenská

*Department of Botany and Zoology, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic

Males evolved various strategies to diminish or avoid competition between their sperm and sperms of rival males within female genital tract. They can prevent female remating by applying mechanical barriers into her genital openings after the copulation. Mating plugs are very common among spiders, but the factors affecting their deposition as well as their impact on female mating possibilities is far from being fully understood. We investigated morphological and behavioural aspects of the process of amorphous plug deposition and removal in two spider species (Micaria sociabilis and Philodromus cespitum) and found out that the plug occurrence, properties and consequences of plugging differ significantly between the two species. Both species share similar morphology of female genitalia, as both copulatory openings are situated in a single depression (i.e. atrium) which allows the male to monopolize the female with a single insertion. The plugging, however, has a different effect in both species. While in M. sociabilis, complete plugs indeed prevent the female from further copulations, in P. cespitum the plugs can be removed by subsequent males even if they fully cover the atrium, and so the female can modify the effect of plugging simply by deciding to remate. In M. sociabilis, females seem to control the plug deposition process as they may terminate the copulation before a complete plug is deposited. The combination of morphological and behavioural studies helped us to understand the mechanism of plug extrusion and its implications for plugging rate and its potential for female control