BBC: In Brazil, a blind fish found again. In a well. No word how it got there.
It took me two runs through a BBC story by Matt Walker before it sunk in why it left a sense of dissatisfaction after the first look. The news is good, a reminder of the never-ending discovery of new and wonderful things about creatures on Earth.
It is, specifically, that a fish known only from one sample has been rediscovered in Minas Gerais state in Brazil. It is eyeless and lives underground. It belongs to a family of fish whose other members all live above ground and have eyes.
Walker provides basic information. He reports the delight of scientists and their beliefs it offers a good lesson in evolution. If you like, read it before the next graf, to see if you are left with the same puzzle as I am.
Here it is. The story says the first fish was found many years ago during a well-digging operation. And the contemporary ones also were found in wells. The fish may have disappeared from the academy of science, but local people said they occasionally saw fish in their wells. OK, it’s an underground fish, and wells go underground. But most wells don’t have fish swimming into them from their walls. Most wells reach water tables and aquifers that are in porous soil or rock formations – water travels through them as it would through a sponge. I don’t believe that a guppy can swim through a sponge.
One suspects that this region is underlain by caverns and caves, perhaps it is a karst, or limestone-rich, terrain. And if local wells are dug into underground caves and other substantial, interconnected voids, that’s unusual enough to be worthy of mention in the news story.
- Charlie Petit
p.s. – After finishing this up and still bugged, I put Minas Gerais and karst into Google. I found an article on spaleogenesis including large sinkholes, or “collapse dolines,” well known in China as Tiankengs. It describes locales where others exist. One is in Brazil – in Minas Gerais.
May 11th, 2010 at 4:12 pm
It took me a few trolls to catch on to”above ground” and even “underground” fish. “Surface water dwelling” and “aquifer dwelling” fish, maybe? Otherwise I think of fish levitating or burrowing–possibly in beret and trench coat.
May 11th, 2010 at 4:19 pm
BTW, a recent Attenborough/BBC TV special (maybe the “Caves” segment of the Planet Earth series) has spectacular video from a vast underground water system in Central America, I think. Must-see TV
May 11th, 2010 at 4:29 pm
Yep: That’s the video, and the place was the Yucatan. Apparently the Mayans flourished without rivers or lakes, just this underground system.
May 12th, 2010 at 10:35 am
Part of my brain was off line when I wrote that post. It shouldn’t have been so hard for me to realize the ancient Mayan city in Belize is in karst. I don’t know how many times I’ve read that in the Yucutan, Maya society rose largely without benefit of surface rivers and streams – runoff tended to drain into caverns in the limestone. Hence the cenotes, or sunken pools used in sacred rituals.
More interesting might be whether the Maya managed to irrigate crops, or if their terraced farmlands depended entirely on rain.