Male spiders look for 'hotter talent' even after their penises snap off

London, Apr 26 (ANI): Male orb web spiders, who only have two chances to mate in their lives that is made even more complex by the fact that females often eat them, still look around for heavier and more fertile females if they've mated with a small one the first time round.

These complex creatures have a difficult choice when it comes to fidelity, as their "pedipalps", used to transfer sperm into the female spider snap off.

"Amongst spiders, regardless of age, heavier females are the most fertile," the Daily Mail quoted Klaas Welke of the University of Hamburg as saying.

"Males were more likely to mate twice with the same female if it was early in the day, she was heavy, and if the nearest other females were sub-adult.

"Males kept on searching for a second female if it was late in the day and the first female was light. We found that bigynous males preferred to 'trade up' to heavier females as second mates, but ran the risk of attempting to copulate with already mated females," Welke said.

Sex for male orb web spiders (Argiope bruennichi) is a two shot affair since the act of mating destroys their genitalia.

If they survive being eaten during their first encounter with a female, they have two choices - to mate again with the same female or try to find a new partner.

Most, scientists were shocked to find that the spiders shopped around - even at the risk of mating with a female who has already been fertilised by another spider.

Monogamous behaviour, such as mating for life, is thought to evolve when paternal protection of the female increases fertilization success.

For cannibalistic spiders, monogamy means that the life of the male can be very short indeed.

However this can improve chances of fatherhood: males of the black widow spider can increase the duration of mating, and hence the likelihood of successful fertilization, by allowing themselves to be eaten.wo thirds of the monogamous males were eaten after their first mating.

These males, which only managed to mate once, tended to mate with the oldest and heaviest females.

"These females are the ones which have the highest fecundity and which are most ready to lay their eggs. While these males do not have a second chance at mating their probability of reproductive success is high," Welke added. (ANI)