Science roundup

What do ancient hippos and ant sperm have in common? We don't know, but let's learn something about them anyway ...

What did one ant sperm say to the other ant sperm? STROKE! Image courtesy of Ed Hawco via wikimedia commons

What did one ant sperm say to the other ant sperm? STROKE! Image courtesy of Ed Hawco via wikimedia commons

In some species of bees, wasps and ants, males enjoy the dubious pleasure of dying shortly post coitus. The fertile females of these species, on the other hand, can live for many years. So, an enterprising insect lad has but one shot to ensure his genes live on, stored in the female’s sperm vault — or spermatheca — and thence in her subsequent offspring. The sperm of one species of desert ant, Cataglyphis savignyi, have hit upon an enterprising solution to beat out the competition: synchronized swimming.

In a study published June 11 in Biology Letters, a team of scientists found that the desert ants ejaculate clumps of between 50 and 100 sperm. The sperm are bundled on one end into caps, like a handful of wet spaghetti noodles jammed into a shot glass.

The sperm flotilla can navigate the female ant’s anatomy upwards of 50 percent faster than a lone sperm. Hooray for teamwork!

It's unclear whether the ancient hippos were doing the dance from Fantasia. Image courtesy of  Lyndi & Jason via Flickr.

It’s unclear whether the ancient hippos were doing the dance from Fantasia. Image courtesy of Lyndi & Jason via Flickr.

It’s old news, but 1.4 million years ago a hippopotamus took a dip in Kenya. Scientists working at the site, called Koobi Fora, examined fossilized footprints in the ancient body of water. Then, they observed modern hippos swimming some laps and compared clues from the fossils to the modern animals’ behaviors.

Based on the similarities, it appears that the ancient tracks came from young or pigmy hippopotami.  The fossilized tracks indicated that the ancient animals used the same distinctive style of swimming that modern hippos employ. Called punting, the animals sometimes move by propelling themselves off the bottom then gliding forward like regal underwater blimps.

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