Little male spiders much better lovers than larger cousins

December 8th, 2008 - 4:16 pm ICT by IANS  

Washington, Dec 8 (IANS) Little male spiders make vastly better lovers than their larger cousins because they’re quicker to mature and more agile, says a new study.In field enclosures, researchers simulated two competitive contexts favouring the development of differently sized male redbacks (Latrodectus hasselti).

The larger males were more successful at mating with and impregnating females when they competed directly with smaller males.

However, when faster maturing smaller males were given a one-day head start, reflecting their earlier maturation in nature, they had a 10-times higher paternity rate than larger males.

Courtship between redbacks lasts an average of 50 minutes when males are competing and 4.5 hours for single, non-competing males. Copulation lasts from six to 31 minutes, and males are usually injured or killed during the process.

“The results reveal that big males don’t get it all their own way,” said co-author and post doctoral fellow Michael Kasumovic, University of New South Wales (UNSW), said an UNSW release. He co-authored the paper with Maydianne Andrade of the University of Toronto.

“Nature favours larger and smaller males under different circumstances. Larger males experienced a longer maturation process so they are unable to search for and mate with females and produce offspring at the same rate as smaller redback spiders,” he said.

“Large size and weaponry are strong predictors of a male’s competitive strengths because those traits help them dominate smaller males when they compete for food and mating rights.”

The study was published in the current online issue of Journal of Evolutionary Biology.

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