Males produce faster sperm for sisters

May 07, 2014 by David Stacey
Males produce faster sperm for sisters

(Phys.org) —Mating with relatives, or inbreeding, can be costly to both sexes, and in many species males and females avoid mating with siblings.  However, the latest research adds a twist to this story by showing that male guppies produce faster sperm when paired with their sisters.

In the study published in the Royal Society journal Biology Letters, Professor Jon Evans, Dr Clelia Gasparini and Honours student Luisa Fitzpatrick from the Centre for Evolutionary Biology, within the School of Animal Biology at The University of Western Australia, exposed male (Poecilia reticulata) to either full sibling or unrelated females to determine whether their courtship and ejaculate expenditure differed.

Consistent with expectation, the authors found that male guppies (a livebearing freshwater fish) direct less courtship towards their sisters compared to unrelated females.

However, they also found that males produce ejaculates with faster swimming when paired with sisters.

"We interpret this latter finding as evidence for sexual conflict because in guppies females exhibit 'preferences' for unrelated sperm," Professor Evans said.  "By producing more competitive sperm when mating with siblings, male guppies may potentially circumvent the females' natural preference to avoid inbreeding."

The researchers suggest the findings may reflect sex-specific responses to inbreeding, whereby males tolerate higher levels of than .

Irrespective of the evolutionary basis for these findings, the research clearly shows that male guppies are capable of recognising their kin and adjust both their courtship and sperm quality accordingly.

Explore further: From worker to queen at the drop of a gene

More information: Paper: rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2014.0166

Related Stories

Why guppies have genital claws

Aug 02, 2013

New research from evolutionary biologists at the University of Toronto shows that the male guppy grows claws on its genitals to make it more difficult for unreceptive females to get away during mating.

Male guppies ensure successful mating with genital claws

Jul 24, 2013

Some males will go to great lengths to pursue a female and take extreme measures to hold on once they find one that interests them, even if that affection is unrequited. New research from evolutionary biologists ...

Unattractive guppies have better sperm

Jun 07, 2010

(PhysOrg.com) -- Scientists studying tropical guppies have discovered that the less colorful and attractive males have better quality sperm, while the attractive fish invest in their appearance at the expense ...

Offspring benefit from mum sending the right message

Apr 16, 2014

(Phys.org) —Researchers have uncovered a previously unforeseen interaction between the sexes which reveals that offspring survival is affected by chemical signals emitted from the females' eggs.

Research shows male guppies reproduce even after death

Jun 12, 2013

Performing experiments in a river in Trinidad, a team of evolutionary biologists has found that male guppies continue to reproduce for at least ten months after they die, living on as stored sperm in females, ...

Recommended for you

South American parrot in trouble: researchers

10 hours ago

A South American parrot with a wine-colored chest is in deep trouble, with its population down to some 3,000 and a habitat reduced to a speck of what it once was, researchers said Tuesday.

From worker to queen at the drop of a gene

19 hours ago

Biologists from the University of Leicester have discovered that one of nature's most important pollinators - the buff-tailed bumblebee – either ascends to the status of queen or remains a lowly worker ...

What is the best way to kill a cane toad?

20 hours ago

Like many pests, cane toads are killed in their thousands in Australia every year, especially by community-based 'toad-busting' groups. New research has now revealed the most humane way to do it.

Petrels tracked across the Oceans

20 hours ago

Staff at British Antarctic Survey (BAS) are following the journeys of White-chinned Petrel fledglings as they make their first journeys over the South Atlantic Ocean in search of food. The birds have been ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Rick150
not rated yet May 08, 2014
It seems to me so often a human perspective gets in the way of research. It maybe quite possible that the genetic traits passed on through some close relationship may be desirable occasionally which we humans find objectionable. How do I know this? Used to be a farmer from a farming family.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.