Friday, March 22, 2024



The Pupfish

Interesting facts always pop up when doing research for items to blog about.

Pupfish and Charles Manson? Not two things that naturally go together.

Pupfish look and sound like they should be fun. In America, the most famous pupfish are the Devils Hole pupfish, living, as they do in the Devils Hole on the Nevada side of the Death Valley National Park.

The Devil’s hole is a water filled cave, 500 feet deep – though how they know that I’m unsure because nobody has ever reached the bottom. The species that live there are found nowhere else, they have evolved, confined to that body of water, for 12000 years or so.  They are ‘Cyprinodontidae’ and are thought to have evolved from a common ancestor of other such fish, just one species that lived in the glacial lake,  Lake Manly (620 square miles), somewhere around 185,000-128,000 years ago. As the lake shrank and separated into smaller bodies of water, so the pupfish set about evolving.

Their cousins, on the island of San Salvador, Bahamas live in two small lakes, in very closely defined ecological environments and they have the fasted DNA evolution of any fish. If their environment changes, then so do they. The usual change is external forces altering the algae that they feed on. If that algae does not suit them, they simply evolve so that it does.

The Devils Hole pupfish is the rarest fish on earth, and the first species ( of anything I think) to be officially classed as ‘endangered’.  There were maybe only 68 of them around in 2013 but numbers seems to be on the rise again, up to 250 by 2023.

These wee guys, only ¾ inch long, enjoy a constant temp of 92 (33 in old money) and they live mostly close to the surface, foraging and fighting, playing and spawning on the rock shelves. Like their Bahamian cousins, they live mostly on algae, decaying vegetation, and the occasional insect. The best algae becomes available when the barn owls are roosting in the higher parts of the cave, and their excretions increase the  nutrition of the water hence better quality algae and fitter pupfish.

When large earthquakes happen around the planet, the water in the devils hole can slosh around, as much as two meters up the walls of the cave.  A 7.2-magnitude earthquake in Mexico (2,000 miles away) created such  a wave in the Devils Hole and that has led to the question – is there a huge subterranean network of waterways down there somewhere. There’s a similar argument for Nessie!   The term underground aquifer of prehistoric origin sounds a bit Jules Verne. But that could be exactly what is going on here.

Whether the pupfish enjoy these minor tsunamis or if they find it rather alarming is not recorded but the action of the sloshing water does disrupt life on the shallow rock shelf the algae grows on.

Now, the fish are monitored by scientists and there’s a pupfish webcam in the visitor centre at Death Valley, where you can watch the wee fish getting up to various malarky in their tiny eco environment.

And Charlie Manson? Well, I think we know of his travels around the Nevada deserts. The man himself loved Death Valley and believed that the Devils Hole might be a portal to the underworld. So he sat near the edge for three days, meditating, thinking that this indeed might be his much desired portal to hell, but he couldn’t find out how to drain it.

Which was probably a good thing.  


  1. It's uplifting to know that three quarters of an inch can draw so much attention in this world of jumbo everything. Jeff

  2. Or, if you want to be happy stay at the bottom of deep black hole and ignore everything else!