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Best photo of pores

Observed: 12th September 2012 By: AmoebaAmoeba’s reputation in InvertebratesAmoeba’s reputation in Invertebrates

Found in a rainwater-filled bucket in Surrey.
Colour: pale straw-coloured to chocolate brown.
Appears to be colonial, covered in small pores. My stereo microscope is limited to 70x. So I can't see great detail, especially through water. These were photographed at 22.5x, through the eyepiece.
Habit - sessile and attached to plant material – fine stems. I have found a half-dozen of these and they appear to have grown around the (update: grass) stem.
I first thought it might be a sponge, but I now doubt this. I failed to find anything like these in my freshwater wildlife books and have failed to find anything on the .net.
The ostracod is ~ 1 mm long.
Date of discovery 11th Sept 2012.
The second and third photos were taken in shallow water, only a few mm deep. Not all these objects are the same. They appear to be of at least two separate types. The first are the golden yellow to brown types with a porous surface and variable shape. The second type is greenish-brown to dark chocolate-brown and mostly smooth, but at least one has ridges. The second group are broadly bean-shaped
If these had been laid on twigs out of the water, of rather larger size and found in Southern Europe, I would suspect they were potentially oothecae from a praying mantis, although I've not checked whether the shape matches any oothecae, because they clearly can't be those.
The length of these is roughly 1 mm. [Update: I've measured some of these and they vary from ~0.8 mm to ~1.5 mm] Measured with a Starna Micro-Mike 20x pocket microscope with a measurement graticule].
The history of the bucket of water is uncertain (I can't remember). Although, because it contains ostracods, I can only assume that it's had pond-water added to it at some time.


No identification made yet.

Species interactions

No interactions present.


Nick Upton's picture

Freshwater sponges / Bryozoa...

I thought sponge too at first, and it is just possible as 2 european freshwater species are now found in the UK: Spongilla lacustris and Ephydatia fluviatilis see and your mystery thing just about matches some images of E. fluviatilis eg: some of the forms shown on the german site: BUT that seems to be a riverine species, so am not sure it's likely in bucket.... and there may be another explanation. Something about the cell-like patterning made me think of Bryozoans and that may be another slim possibility - there are some FW ones: shows various dutch species. Lophophus crystallinus at least is found in the UK (rare. but likely under-recorded), but pics of this don't match well. I like a mystery, but am not sure I have the answer!

Nick Upton, naturalist and photographer.

Amoeba's picture


Thanks for your reply. I've had another look at bryozoans, I'm wondering if it's an over-Wintering stage see my comment below.
Once again, thanks for your help.

Amoeba's picture

Possible ID

These may be the statoblasts (sessoblast) of the bryozoan fredericella sultana.
Isn't it amazing what one can find with a low-powered microscope!

Most of these are bean-shaped, the one I photographed was the one that wasn't. Perhaps it's something else, or damaged.

See image
(c) Piptoblast or sessoblast of Fredericella sultana.

Nick Upton's picture


Maybe! I think it's going to need an expert who has seen these before to chime in to be sure of anything, though. I'm familiar with a number of seashore sponges and Bryozoans, but not with Freshwater varieties and life stages (apart from film footage of sponges in Polish marshes where they'e common). An expert may need to know the history of your rain-bucket and how long whatever it is might have had to develop and how it could have got there. I hope the mystery is solved, as I'm intrigued. I'm sure a lot of little known stuff gets overlooked, especially when you get down to this scale.

Nick Upton, naturalist and photographer.

John Bratton's picture

Is it definitely alive? I've

Is it definitely alive? I've never found anything like this in 40 years of poking around in ponds, but that third picture looks a little artificial. What is its consistency? Hard, or jelly-like? Are there any signs of it drawing water currents into the pores? Or any tentacles that emerge from them? I'm just wondering if it could be some kind of adhesive that has stuck to the stems which have then dropped into the bucket.


Amoeba's picture

Is it alive?

I looked specifically for tentacles, polyps etc., and failed to see any, even after periods of being left undisturbed.
My assumption that it was alive, was based upon the fact that it possessed a fine structure and appeared to have grown or been deposited around plant stems.
Water-currents: these were not noticed, but then I suspect these would be hard to identify with the equipment that I possess.
As for the bucket, I suspect the bucket has been in that location for several years under an overhanging Cherry-Laurel bush. Only recently, after this discovery was it retrieved and placed in the open.

Consistency: This was an coloured externally an olive greeny-yellow, broadly bean-shaped in appearance, with pores. I cut one in half. It cut through with slight resistance. This was cut with a sharp knife possessing a laminated blade, high carbon steel edge, not a scalpel. The knife cut through suddenly, as if the object suffered structural failure suddenly. Nothing spilled-out as far as I can tell. The object retained its shape. It is not gelatinous. The pieces retained their geometry in side-view. I'm uncertain about the original cross-section, but after the cut, the cross-section was broadly D-shaped, as if the side resting on the dish had been flattened. I was unable to discern details of the internal structure. I crushed a cut piece with forceps and it fractured.

I believe that to obtain more detail would require preparation of the object for a microscope slide and a higher-power compound microscope. Probably 100x or greater.

So to answer your question, I can't be sure.

Nick Upton's picture


The 2 new pics do look a bit like some kind of foam - maybe injectable insulation material.... The history of your bucket and who's been near it may help solve the mystery! Have you had cavity insulation injected or some such in the time the bucket has been out?

Nick Upton, naturalist and photographer.

Amoeba's picture


I don't believe it's cavity insulation.
a) Because all the (nearby) houses in our road have solid walls. There are extensions, but the ones I know about were built incorporating block insulation. As I understand it, insulation foam is either applied wet, or as pellets.
b) The cavity wall foam idea doesn't seem likely, because these are all adhering to underwater plant material. If wet PU foam has rained-down, there would be this stuff everywhere, on the bucket, as well as in it.
c) IIRC Block insulation is typically rockwool, which would appear fibrous and fluffy.
d) These objects are pretty consistent, size-wise. If these were a random by-product of human activity, I would have thought they would be much more variable in size, subject to sorting by size / density as a result of wind and other processes. That would mean these would be elsewhere too, but I haven't noticed any in nearby containers (essentially where I've examined material with a microscope.).
e) Polyurethane foam is used for cavity walls, but the essence of foam insulation is thin walled closed bubbles filled with a gas, to reduce thermal conduction. I don't believe this is any kind of gas-filled foam, because the density of these objects is too high. While I can't measure the density, I have observe that these sink in water, therefore the relative density is greater than water, but only slightly so. Googling tells me that PU cavity wall foam insulation has a density of ~220kg/m³, so it would be highly buoyant in water.

I'm puzzled.

Nick Upton's picture


I think these remain unidentified non-floating objects... but do keep looking for signs of life / something hatching out, whatever!

Nick Upton, naturalist and photographer.

Amoeba's picture


Thanks Nick. I will, and thanks for your helpful and thoughtful observations.