Sunday, August 19, 2012

Spider Sunday: Breaking News

I was debating with myself about what species to feature in this week’s “Spider Sunday,” when I got wind of a story that immediately trumped all other options. Not only was there the formal announcement of a new species of spider, but one that represented an entirely new family of spiders as well. It takes a very unique species to demand its own family, but this arachnid is strange indeed.

Several press outlets carried the story, many including images of this odd spider. Not surprisingly, there is some conflicting information and perhaps exaggeration.

What is known for certain is that the spider had to be formally described and named before the discovery could be made public. That official record is in the latest issue of the professional journal ZooKeys, a peer-reviewed online publication of Pensoft Publishers. This in itself is newsworthy. Online journals shrink the timeline between discovery of species and the broadcast of those discoveries. Even so, this spider was found initially in 2010. Online journals also mean that you don’t have to live next to a university library to be able to access authoritative serial publications.

Let’s get back to the spider, though. What makes it unique? There is no question that the most distinguishing feature is the long, articulated, blade-like claws on the tip of each leg. The spiders are found on the ceiling of caves in southern Oregon (one report included northern California and British Columbia in the distribution), suspended upside down in very small, minimalist webs. It is thought that they wait for small, flying insects to come within range of their lanky legs, then hook their prey with those sickle-like claws.

These are not small animals. The legspan of a mature specimen can exceed two inches (five centimeters). As scientist Charles Griswold, the lead author in the journal article, explained in a BBC radio interview, they look even larger in the beam of a headlamp. The spiders are not blind, but have only six eyes as opposed to the usual eight for most spiders. Live specimens in Griswold’s lab at the California Academy of Sciences refused to eat.

The last time a new species of spider required the erection of a new family was back in 1990, when a South African spider was described. You have to go back to the 1890s to find the last time a new family of spiders was established for a North American spider.

The new family is named Trogloraptoridae. The spider’s official species name is Trogloraptor marchingtoni. The genus name is a combination of Greek and Latin that translates to “cave robber.” The species is named for Neil Marchington, a deputy sheriff for Deschutes County, Oregon, who first showed scientists the spiders inside a cave. Marchington is also a member of the Western Cave Conservancy and an amateur biologist.

Cave organisms in general are poorly understood, and highly vulnerable. Populations of cave animals tend to be small, specifically adapted to a lightless habitat, and prone to perish with the slightest change in that environment. It is largely thanks to the efforts of organizations like the Western Cave Conservancy that any effort at all is made to preserve and protect caves. Irresponsible spelunkers (cave explorers) can easily damage a cave just by touching formations and thereby changing the chemistry that forms caves. Vandals can deface and destroy caves; and development above a cave can result in contamination of groundwater that courses through the cave, if not causing the cave to collapse in part or in its entirety.

I take special delight in learning that this new species was found in my home state of Oregon. The coniferous forests there have relatively poor biodiversity compared to deciduous forests, deserts, and rainforests, but there is no argument that the species found in the Pacific Northwest are often unique. I hope to get back there again in the future, if only to find insects and spiders that I know exist there, but that I have never seen. I’ll have to add this spider to that list!

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