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Sperm trading can resolve hermaphrodite mating conflicts
October 11, 2005By directly manipulating mating performance in a tropical sea slug, Chelidonura hirundinina, researchers of the University of Tübingen have now shed light on the bizarre reproductive conflicts encountered by hermaphroditic animals. In some hermaphroditic species, such as C. hirundinina, mating partners may insist on copulating as a "male," "female," or both, resulting in unique biological conflicts over gender.
Sexual interactions in so-called cross-fertilizing simultaneous hermaphrodites, such as earthworms, snails, leeches, and some fishes, have long challenged researchers' understanding of how established theories regarding sexual selection apply in cases of hermaphroditic species. For example, combining male and female gender in one and the same individual, hermaphrodites have been predicted to frequently be at conflict (theoretically speaking) about which sexual roles to play, because matings are often more costly, in terms of evolutionary fitness, to one gender than to the other. In such cases, hermaphrodites are predicted to share a preference to copulate in the more beneficial gender role. This would appear to make the interests of any two potential mates incompatible. For 20 years, evolutionary biologists have speculated that hermaphrodites may solve such mating conflicts by "trading sperm," that is, giving sperm only when the mating partner follows suit. However, this prediction had never been proven experimentally.
In the new work, researchers Nils Anthes, Annika Putz, and Nico Michiels generated individual sea slug hermaphrodites only capable of performing a "dry" copulation-that is, without sperm transfer. Sea slugs that mated with such a "cheating" partner interrupted sexual intercourse significantly sooner than did control pairs. This supports the concept of sperm trading, where mates negotiate mating roles in order to balance sexual interactions.
Cell Press
Cell Press
Mate or hibernate? That's the question worm pheromones answer
If worms could talk, they might tell potential suitors, "I like the way you wriggle," complete with that telltale come slither look.
Living laboratory found on shoreline statues
A team from the University of Liverpool's School of Biological Sciences have found that the 100 life-size statues which make up Antony Gormley's 'Another Place' art installation on Crosby Beach have become a haven for a settlement of a particular breed of barnacle-Elminius modestus.
Hermaphroditic plants have genetic advantage in areas where extinctions are frequent
In one of the first studies to empirically compare the reproductive success of hermaphrodites and male and female populations, biologists from the University of Oxford make use of the rare and extreme sexual diversity displayed in a species of European weed to test the hypothesis that hermaphrodites have been selected in regions with frequent extinction and re-colonization.
Pollutant threat to oyster industry
A study published today reveals that a common industrial chemical causes sexual deformities in oysters, producing large numbers of hermaphrodite animals. The chemical, nonylphenol, is a breakdown product from a surfactant widely used in detergents, dispersing agents, herbicides, spermicides and cosmetics. Dr Helen Nice who undertook this study at Royal Holloway, University of London, says, 'Our results may cast doubt on the widespread use of this chemical in many human products including contraceptive spermicides.' Nonylphenol is a known endocrine disrupter - chemicals that interfere with the hormones of animals. It is discharged through sewage effluent and is therefore widespread in the aq
Science Of Strawberries
Goran Ivanisevic's offer to serve strawberries at this year's Wimbledon may be a more useful job than he imagined. As well as delicious with cream, this symbol of the summer could help fight cancer according to scientists. Research has shown that natural plant chemicals in strawberries can inhibit the growth of cancer cells. And now scientists at the Institute of Food Research have begun work to identify the compounds responsible. "The modern strawberry is just one of hundreds of varieties cultivated worldwide. There are also about twenty wild species. They all have different properties - visible in the size, shape and colour of the fruit, or the size and abundance of flowers. The aim of
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