Bootlace worm - Lineus longissimus
Image: Steve Trewhella (published on the MarLIN Web site)
This animal is among the world’s longest. It may reach a length of more than 50 meters!
I’ve been discussing the fictional sandworm of Dune. So far, the data indicate that the planet Arrakis, or Dune, could exist, but that life could not have evolved on a planet in orbit around Canopus (where Herbert places Arrakis). Even if Dune were terraformed and introduced life existed there, it could not long flourish in the absence of plate tectonics.
Now let’s look at what types of worms exist on Earth, where we enjoy abundant water and oxygen, and plate tectonics regularly causes earthquakes and volcanoes that recycle our carbon dioxide (among other things).
The Bootlace Worm, Lineus longissimus, grows over 50 meters long! That’s over 150 feet, and while not quite reaching the proportions of Herbert’s sandworms, it comes pretty close!
This lowly animal won the title of World’s longest animal, when a specimen measuring 180 feet beat out the longest dinosaur and the Blue Whale.
Along the coast of Norway, scientists found 30-meter long individuals and estimate that they can reach 60 meters when they stretch their body to its full length.
So why can’t Dune’s sandworm be this big?
The Bootlace Worm lives in the ocean, with certain problems like nutrient exchange, water balance, excretion, and mobility taken care of since it’s immersed in water. A terrestrial animal faces numerous challenges, such as water balance and thermoregulation that marine organisms don’t have to deal with.
And then, Dune has no oceans and Herbert said that water is poisonous to the sandworm. So we won’t find Lineus longissimus or other animals like it on Dune.
I haven’t looked at any of the linked pages yet but was wondering what diameter is reached by the longest specimens of the worms you mention?
Some of us have speculated that the sandworms of Arrakis might be a type of communal organism based on the “fact” that when exposed to water they fission into sandtrout. (Remember what happens to Leto II when he falls into the river?)
In a comment on my blog, someone also pointed out the segmented nature of the worms. I think there is something in the books about the individual segments—if a worm is broken apart somehow—being capable of growing into a new worm, similar to terrestrial earthworms. (It’s been a long time since I took a biology class, so I forget what determines the viability of segments in the latter case. ???)
Just two more things to throw into the mix.
Comment by SandChigger — January 27, 2008 @ 9:35 am
Although it has nothing to do with the kind of worms that Herbert described in Dune, in the worms family, parasite worms such as broad fish tapeworm is the largest of the human tapeworms
can be as long as 20 m (approx. 67 feet).
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/Tapeworms.html
Also in the same link, the second longest tapeworm is the Beef Tapeworm measures an average of 13 to 39 feet.
The tapeworms have the capability to grow again if their head stay in the gut. In the above link, they say about the pork tapeworm:
“Dr. Brooks repeats the same thing other researchers have said, “If the scolex (head) remains in the gut, it will soon grow another worm.”
More about Diphyllobothrium latum, the broad fish tapeworm:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/Tapeworms.html
Yikes!
Bruno
Comment by Bruno Haché — January 28, 2008 @ 8:51 pm
The ribbon worms are usually 5-15 m long but some are over 30 m, and are usually 5 mm in width. That’s all I’ve found on width or diameter. You can see why they call them bootlaces!
The segments growing into a new organism would imply some sort of communal organism, and I know of lower animals that do this, but am unaware of any higher animals with this capability.
Sorry, I’ve been super busy with a writing deadline and haven’t been able to look up more info on this, but will try to get to it later.
Comment by sibylle — February 12, 2008 @ 9:55 pm