'Mating plug' in females stops rivals' chances

London, To ensure the fidelity of their mates, the male dwarf spiders deposit a substance referred as a "mating plug" inside females as the substance makes it difficult for rivals to copulate and squeeze in sperms.

The effectiveness of these plugs depends not only on their size but also on their age, a new study showed.

"If 'plugs' were more than a day old, the chances of a second male copulating with the female were much lower," said Katrin Kunz, an evolutionary biologist at University of Greifswald in Germany.

For the study, researchers observed mating sessions between virgin females and males, removing the males after different lengths of copulation.

The longer the copulation lasted, the larger was the plug size.

After introducing the females with different plug sizes to other males, the researchers analysed the females using a scanning electron microscope.

The time between the first and second mating varied, depending on the plug's age, the researchers found.

The study appeared in the journal in Behavioural Ecology and Sociobiology.

Source:IANS