On Camera: A Tale of Two Species


babyhscrab.jpgThat’s right folks, to your right is a baby horseshoe crab. The photo, meant to be wallpaper for your computer screen, is one of the educational and fun extras offered on the NATURE program’s website. After being thrown into the Internet age, science shows like NATURE and NOVA stepped up their image by adding video, downloads, links and audience participation to their homepages. You can even be their friend on Facebook.

Accompanying tonight’s premier on WGBH of “Crash: A Tale of Two Species” for instance is a map for visitors to report horseshoe crab sightings and an article explaining why the crabs are collected for their blue blood. (More on that below).

In her documentary, writer, director, producer Allison Argo, was able to tell a compelling narrative about the relationship between horseshoe crabs, humans and a little shorebird called the red knot. For centuries the red knot has relied on the egg laying of horseshoe crabs in the U.S. to fuel its journey to the Arctic breeding grounds. However as millions of the crabs have been harvested over the past few decades, the number of eggs have dropped as so has the number of birds, by about 70% of their known population.

One question that quickly comes to mind is why would we hunt horseshoe crabs? The 35-million-year old creatures are not that pretty or tasty for most of us, but apparently they are a hit with biomedical research companies and eels.

Horseshoe crabs have, according to Argo, an evolutionary pot of gold. Their blue blood transports oxygen throughout their bodies with copper, rather with the familiar hemoglobin. It also is a natural antibiotic. The moment blood cells meet an invader they clot and eliminate the threat. The crabs are collected by fishermen and sold to companies like Endosafe, part of Charles River Laboratories, who bleed 1/3 of the crabs’ blood supply and sell it at $15,000 per quart. Most of the crabs are returned to the ocean, but about 15% do not survive this process. The blood is then used to test potential treatments for toxins and Argo stresses we have all benefited from this technology.

The other connoisseurs of crab are eels and snails. Some Atlantic fishermen depend on the crabs to use as bait. However, because horseshoe crab populations are dropping, there is a moratorium on catching them in their major breeding ground. Scientists at DuPont, a research and development company, are in the process of developing artificial bait. One that has been successful is a gel flavored with horseshoe crab.

If this information doesn’t get your interest, at least watch the documentary to see a fisherman demonstrate how harmless the horseshoe crab’s pincers are by holding one up to his face. Now that should be a challenge on fear factor.


Posted by Joseph, under reviews  |  Date: February 10, 2008
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