Scientists report for the first time that a snail’s seminal fluid proteins can suppress the mating success of the male side of its hermaphroditic partner.
by Rina Shaikh-Lesko
Although copulation is often brief, males of many animal species leave a lasting impression on their mates. The seminal fluid they deposit contains not just sperm, but proteins that can alter the physiology and behavior of the female, often in ways that hurt the paternal success of her subsequent mates.
Among hermaphrodites—animals with both male and female reproductive organs—mates themselves are potential competitors, too, and copulation gives seminal fluid proteins the unique opportunity to directly manipulate the recipient’s male as well as female function.
Ovipostatin, a seminal fluid protein (SFP) in the hermaphroditic freshwater snail Lymnaea stagnalis, cuts egg production in half in the sperm recipient, according to a 2010 study led by Joris Koene of VU University Amsterdam in the Netherlands.
It’s been theorized that SFPs might also affect the sperm-producing capacity of recipient snails—their maleness—to reduce competition within a population. “It had been predicted … more than 30 years ago, but no one had properly tested it,” says Koene…
(read more: The Scientist)
illustration: © Scott Leighton
Can Snowshoe Hares Evolve to Cope With Climate Change?
The color-changing North American animals may adapt by staying brown for longer periods.
by Emma Marris
There’s something odd about a bright white snowshoe hare motionless and alert—without any hint of snow nearby.
Gleaming white on a brown background of dirt and leaves, the hares, which are native to the mountain ranges of North America, might as well be wearing an “eat me” sign for lynx and other predators.
Scott Mills and Marketa Zimova of North Carolina State University call this “mismatch”—when the hare, which turns from brown to white as the fall becomes winter and back again in spring, doesn’t match its background.
Usually, hares seem to time their color change pretty well. Now the average hare is mismatched only about a week out of the year.But climate change is likely to make such awkward—and potentially fatal—mismatches much more common, the team said this week at the North America Congress for Conservation Biology in Missoula, Montana…
(read more: National Geographic)
photo by Robert Harding/World Imagery/ CORBIS
Eerie, beautiful, captivating images of sea urchins mating and being born (that little triangle guy is a baby sea urchin).
These are a glimpse of how life begins in the deep ocean — and there’s a lot of life down there. The oceans provide about 190 times as much living space as every other space on Earth — soil, air and fresh water — put together. A vast array of amazing creatures live in the depths of this watery world. Squid, jellyfish, and plankton are just a few of our favorites (all shown as tiny babies in that last gif).
Another great look at the alien world of the ocean. See closeups of coral here.