When real life imitates testates: a 2019 ‘Testate amoebae in the real world’ calendar?!

Contributed by Matt Amesbury and Alex Whittle

(Real!) testate amoeba photos used with the kind permission of Ferry Siemensma, Microworld, www.arcella.nl


As testate amoeba analysts, we all spend countless hours staring down the microscope studying and identifying hundreds upon thousands of shells. Perhaps foolishly, I once added up, out of perverse interest, the number of tests I had counted over the course of a three year project developing palaeo records from three Holocene age cores, a couple of shorter cores and developing a regional transfer function. The total was 130,384.

I still can’t quite decide whether this number amazes or sickens me (!), but it certainly does make it understandable that we should all begin to see the familiar shapes and structures of tests when we close our eyes, in our sleep and even in the real world.

Forward on almost a decade from that count-heavy project and I have moved to the University of Helsinki for a year to work on testates from permafrost peatlands. It’s the weekend and I am enjoying a walk in the local forest with my family. We stop for a snack of ruis sippi; circular, bowl-shaped rye crackers that are popular in Finland. My hand delves into the bag and I pull out a freak cracker with the front still attached. The recognition is immediate … keep reading to find out more!


In the true collaborative spirit of our community, a photograph of this most unusual ‘specimen’ soon reaches me back at the University of Exeter. Having myself witnessed a curry resembling my second favourite testate amoeba taxa – Certesella certesi – just weeks before, this starts us wondering … how many other testates are hiding in plain sight, surrounding us in the real world? Others soon followed and we share the first three stories below. (I still deeply regret not taking a photo of the curry!)

Of course, the idea of a ‘Testate amoebae in the real world’ calendar was a natural progression, so please regard this blog as part amusing distraction and part call to arms! Go out into the world, friends and colleagues, find and photograph whatever you can that strongly resembles a testate amoeba and send them in to us!


Centropyxis rye-crackeris

1. Centropyxis ‘rye-crackeris’ (Lat: 60.2165°N, Long: 25.0327°E).
Finnish rye crackers generally exhibit a hemispherical boat-shape morphology, adapted to hold some sort of filling. This one obviously had other ideas and preferred to imitate Centropyxis aerophila type, with its test construction of agglutinated rye grains and a sub-terminal aperture. The specimen was found on 13th August 2018 by Matt (and family) whilst stopped for a snack during a walk around the forested tracks and trails near the Viikki campus of the University of Helsinki.


Difflugia shroomex

2. Difflugia ‘shroomex’ (Lat: 54.5763°N, Long: -5.9356°W)
Many food stuffs that spend their short lives imitating testate amoebae are secretive and prefer to stay out of the limelight, many being digested by unsuspecting members of the public without ever fulfilling their destiny of being recognised for what they really are. However, some are brazen and do everything they can to be found. One such example is this mushroom amoeba with test of agglutinated breadcrumbs (or Difflugia pulex type) who, astonishingly, infiltrated the lunch buffet on day three (13th September 2018) of the 9th International Symposium on Testate Amoebae (ISTA) held at Riddel Hall, Belfast. Found by Matt, who was distinctly peckish at the time and enjoyed the mushroom very much a short while after this photograph was taken.

Lagenodifflugia vase

3. Lagenodifflugia ‘vase’ (Lat: 64.1447 °N, Long: -21.9423°W)
As a word of caution, it is important to consider that not all everyday testates will be disguised as food items. Indeed, I (Alex) believe the stories above may indicate a particular ‘sampling bias’ by their author! Some are a much less ephemeral presence in everyday life and have invested much more energy into creating permanent tests in the hope of being identified – these are the K-strategists of real life testates. This individual was found by Alex, directly after ISTA9 on a wet and windy evening in late September (23rd) in Reykjavik, Iceland. Considering the location of this record in the Northern Hemisphere, after some initial confusion with Apodera vas, we believe this real-life testate to be imitating Lagenodifflugia vas.


Real life testates world map

Distribution of real-life testates currently reported at the time of writing.


Remember that real-life testates may be spotted without warning and when you least expect them so keep your eyes peeled and cameras at the ready. We aim to fill the map with finds across the world and let’s not allow any testate genera to go un-represented!

We cannot wait to hear from you – the hotlines for reporting your real-life testate discoveries are: m.j.amesbury@exeter.ac.uk and aw424@exeter.ac.uk

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