refractal

My other tounge is a Cymothoa exigua

Radiolab this week treats the ever fascinating topic of parasites. In the hour long podcast, Jad Abumrad and Robert Krulwich diffuse into the wondrous world of zombie cockroaches and cordyceps ladden ants (really this one is a must see!). Cordyceps is particularly surreal because, of its hundreds of varieties, each has evolved to commandeer the neural functions of a different species in order to hop another link of the biosphere.

See also:

Brainwashed by a neuroparasite

Discover Magazine Gallery – Zombie animals and the parasites that control them

Cymothoa exigua is a parasitic crustacean of the family Cymothoidae. It tends to be 3 to 4 cm long. This parasite attaches itself at the base of the spotted rose snapper’s (Lutjanus guttatus) tongue, entering the fish’s mouth through its gills. It then proceeds to extract blood through the claws on its front three pairs of legs.

As the parasite grows, less and less blood reaches the tongue, and eventually the organ atrophies from lack of blood. The parasite then replaces the fish’s tongue by attaching its own body to the muscles of the tongue stub. The fish is able to use the parasite just like a normal tongue. It appears that the parasite does not cause any other damage to the host fish. Once C. exigua replaces the tongue, some feed on the host’s blood and many others feed on fish mucus. They do not eat scraps of the fish’s food.This is the only known case of a parasite functionally replacing a host organ.

There are many species of Cymothoa, but only C. exigua is known to consume and replace its host’s tongue.

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Doggerland – Mapping a lost world

Next nature featured one of those discoveries to emerge out of archeology that cannot help but give one a smile of pause and a thought that this too, indeed, will pass.

Doggerland is the name of a vast plain that joined Britain to Europe for nearly 12,000 years, until sea levels began rising dramatically after the last Ice Age. Taking its name from a prominent shipping hazard—Dogger Bank—this immense landbridge vanished beneath the North Sea around 6000 B.C.

Like all landbridges, Doggerland seems to have been a pretty busy thoroughfare for ancient hunters and gatherers. But archaeologists hardly gave it a thought until 2002, when a small group of British researchers laid hands on seismic survey data collected by the petroleum industry in the North Sea.

It is thought that the sea level rose no faster than about one or two meters per century, and that the land would have disappeared in a series of punctuated inundations. According to marine archaeologist Nic Flemming, a research fellow at the National Oceanography Centre of University of Southampton, UK. “It was perfectly noticeable in a generation, but nobody had to run for the hills.”

Although hunter-gatherers usually have any sense of ownership, land would have become an increasingly precious resource as the sea rose, which according researchers Clive Waddington &  Nicky Miller might have led directly to the development of sedentism and territoriality.