Observing freshwater microorganisms that can live on top of a tree!

Last month, I had the chance to enjoy a bit of my summer vacation by going to a beach in the serene province of Zambales in the Philippines. Initially, I only planned to catch some marine zooplankton as I thought those creatures would be very interesting to look at under the foldscope, and would make as cute pets! I used a homemade plankton net to do the job (which I hope I could feature here next time as soon as I get another chance at some ‘vitamin sea’). Unfortunately, the plankton didn’t survive the transit home, and I didn’t even get a chance to look at them intact under the foldscope as their delicate bodies began to disintegrate right away.

Luckily, I had this idea of collecting moss from the trees that grew by the beach at the very last moment, as I thought that I might be able to catch some tardigrades (I’ve never seen them as well). Based from what I know, they love to dwell in moist and mossy environments, and they can survive even the driest conditions by undergoing cryptobiosis. They can be fully “activated” by hydrating their previously dry habitat for 24 to 48 hours, and so I decided to soak the moss I collected in distilled drinking water for 2 days. By the way, the moss I collected were growing on tree trunk about 6 to 8 feet above the ground. I was kinda surprised that they have managed to flourish even under the dead heat of the summer sun.

After 2 days, I squeezed the moss and collected the drippings in another container. I then transferred the drippings to the well plate that came with the foldscope using a pipette, so as to facilitate a systematic survey of the droplets in search for any tardigrades.

Well, as it turned out, I wasn’t able to find a single tardigrade. But what I did found was an assortment of microorganisms that seem to have come from a pond water sample!

Lots of protozoa and algae:

Some nematodes:

And bdelloid rotifers:

I think it’s safe to say that these are freshwater microorganisms because they seem to thrive with just a sustenance of distilled water. However, I’m still wondering how they ended up living in moss that grow 6 to 8 feet off the ground – and near a huge body of saltwater at that! I did some researching, and I found out that just like tardigrades, micro-animals like rotifers and nematodes can undergo a desiccated state but differently termed as anhydrobiosis during conditions of drought. While they are in this shrunken (as with rotifers) or coiled (as with nematodes) state, they could sometimes be carried off by the wind or other animals, and can end up in an entirely different environment, which in this case could be moss on a tree bark. Meanwhile, some protozoans can become dormant cysts along their life cycle, like Colpoda sp., and while in this phase, they can survive harsh conditions like drought. They could also be carried off by the wind or other animals during this phase. However, it is still being debated whether some protozoans like Paramecium could actually undergo a cyst phase.

I guess the most interesting fact I learned from this endeavor is that you could still observe freshwater microorganisms even without having to go to a pond or other bodies of freshwater, if you only know where to look. I plan to culture this find so I could maintain a decent population of these creatures and observe more of them in the future.

As with the tardigrades… I guess I’ll be collecting more moss in the future. Not giving up on finding one!

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