A study of the toughest survivers
When I was living in Jamaica and had a series of science articles similar to this blog in the country’s largest newspaper, “The Gleaner”, I once planned to write a column for April 1st : I intended to explain how excellent the facilities for pothole researchers were in Jamaica. However, as I found out during stays in numerous other countries, it is not just the nation of reggae, Bob Marley, Blue Mountain coffee and Usain Bolt that offers opportunities for pothole research.
You can find pits, depressions, fist- and even football-sized hollows in asphalt, cement, rock, in fact in any hard surface and any country. These voids are characterized by being exposed at irregular intervals to rain or snow, by falling dry for extended periods, becoming burning hot at times or entering an extended period of freeze. Moreover, they have a tendency to get larger with time and accumulate bits of debris. They are not restricted to road surfaces and needn’t be short-lived, but some, e.g. those on the summit of Ayers Rock in Australia, could have existed for millions of years.
After the rain when potholes fill with water, it may take a couple of days and these cavities could be teeming with minute organisms. There would of course be the ubiquitous bacteria and ciliates, but one would also encounter rotifers, tiny soil nematodes (round worms) and maybe tardigrades (bear animalcules). The occasional earthworm would end up and die there. Should the potholes remain filled with water for longer, they’d change colour on account of algae in them; mosquito larvae and perhaps some small water beetles would soon be noticeable in them. A little later one might also be able to observe how damsel and dragonflies as well as other insects with aquatic larvae attempt to deposit their eggs into these small water containing cavities.
In the potholes of Ayers Rock to my great delight I found a few days after heavy rains three kinds of archaic crustaceans, namely tadpole shrimp Triops sp. and the smaller fairy (Anostraca) and clam shrimps (Conchostraca). If the water in potholes generally (and I am now not talking of those on Ayers Rock any more) stays there for longer and the cavities aren’t too small, the first amphibians may arrive as I have seen in North Korea and there might evenually be tadpoles. Should the water evaporate, only those with the fastest development or drought-resistant, dormant developmental stages like rotifers, some tardigrades and nematodes (mentioned earlier as the “pioneers of difficult environments”) will survive.
There are biologists who believe that potholes on account of their unpredictable conditions represent the oldest environment for Earth’s terrestrial colonizers. When I discussed these thoughts on potholes with a Jamaican colleague of mine, he responded by saying: “That’s nothing. I know of potholes that are so big, you’d find fish in them and some of them have even swallowed up whole cars!” Clearly, that’s something that should concern us pothole researchers, for if the authorities upon such remarks jumped into action and decided to ignore potholes no longer, but started to fill them in, where could us urban pothole scientists continue to carry out our important investigations? However, I’m an optimist and feel we need not worry too much.
© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2016.
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