Earthworm culture

STEM Chat
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The “decomposition” is more from the structure of the paper breaking down as water dissolves it - tissue paper is designed to break down like this. Maybe some microorganisms are composting it slowly by now. You can reduce it to a pulp with a few minutes of soaking and pressing. Merely the mechanical impact of earthworms moving through it constantly will keep breaking it down - this is not a result of “eating” or even a lot of decomposition, though undoubtedly there have been microbes introduced - from the earthworm’s body? From the paper? Through the cloth? And the microbes have enough of a culture to feed the worms. Or the worms are “eating” or “slurping” some kind of solution of the paper. The black excretion is the result of eating.

The decomposed paper is just that - fragile wet paper that has been moved a lot - mechanical breakdown. Earthworms have no means to directly ingest paper (or for that matter, most things we give them). Under normal microbial conditions, wet paper will vanish in the bin and become a part of the black compost. Can’t say how much of that is attributable to worms alone, though, since a compost is an ecosystem of sorts. Teeming with all kinds of composting creatures.

This is neither here nor there.

What is mind boggling is that the earthworms are alive. Even if they have found enough of a microbial culture that breaks enough paper down for their needs, there are some other conditions too that they appear to have overcome.

Quite a few of their native conditions are violated and they seem to be fine.

They appear to have adapted to living in light, unless the glass is stored in the dark when not observed. This is mind boggling, because they are evolved to have an aversion to light. Probably because when they find it in nature, the chances of them drying out are high - sun. So with abundant light and high humidity, they have “learned” that this light is not harmful. Or perhaps, lacking an alternative, they manage and will opt for dark if it is available.

They usuallly require fine grains of sand/soil to help digestion. If they are living only on paper, it is unlikely they have that. So they seem to be making do without or there are smaller particles in paper that suffice? Or cellulose being harder to decompose, serves a similar purpose?

Or, it is possible that those growing worms for compost give them optimal conditions to maximize vermicompost production (the “fertilizer” from this will not be as useful to plants - paper has low nutritional value), as the goal is not to test their tolerances but to maximize their production, but they can make do with suboptimal conditions too or adapt…

This is pretty dramatic adaptation for an earthworm.

Now I want to isolate a few of my worms in a glass :smiley:

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Just to clarify, once the paper is broken down, even if mechanically, the earthworms can eat it. They are basically not able to chew and break pieces off.

Which is also how they are a gardener’s friend and not biggest foe - they can’t chew leaves or roots off plants! However, once the leaves are dead and fall to the ground or roots start rotting, they make short work of them, clearing them out, returning them as fertilizer.

But to be able to do that, they essentially need the “food” to be rendered either small enough to swallow, or soft enough to suction/tear into pieces. The mechanical damage to the paper will result in frayed areas and such that the earthworms can eventually eat. Plus there are fungal spores literally everywhere.

Given enough time, everything organic is earthworm food. My astonishment is that the earthworm can sustain itself till enough food can be broken down and be available.

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You seem to have some evidence for the worms coming out before the rains. If this your observation or known to experts working with the worms? Any reference? If it is true, we can use them to predict rain?

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This is our experience too! We feed the worm only with a moist tissue paper. They survive, repair, and regenerate in this meager environment.

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So far, it had been my observation, but in trying to find something else about earthworms escaping bins after that reply, I found the first paragraph on this page. Why Are My Worms Trying to Escape? - Uncle Jim's Worm Farm

It does sound like they are sensitive to air pressure/storms - may or may not coincide with rain? I don’t know.

When it happens, my observation was that they tried to escape the bins if rain was due after a long period of non-rain. Like first rain of monsoon, or after a gap of several days/weeks. But not if it has been raining daily. So I assumed it would have to do with big changes in air pressure or humidity, since a domestic wormbin of course doesn’t get rained on, and this, in any case happens before the rain.

But this is imperfect, since they don’t escape each time either. Maybe a slow buildup doesn’t trigger them?

To use them to predict rain, it would take identifying the trigger precisely and seeing if it is a good predictor of rain and then seeing if there is a way to measure response reliably (for example rising to the top of the bin without escaping may be happening without me seeing those escape artists.

Edit: It is just an observation over the years. I haven’t done much to refine my findings or even observe extensively. It is more like an observation of mom screaming in the kitchen “Sonu, your worms are on the floor” every half an hour before it rains. lol.

Wasn’t that big a deal till earthworm experiments came to my attention and I thought this could be investigated further given an appropriately designed experiment.

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Also, there is one correction to what I said earlier. I had said earthworms eat their weight in food everyday. This is probably not correct. More like over 2-3 days. I had based that statement on the general practice of putting in about as many food scraps as there are worms when getting new bins started and when excess rotting food can attract undesirable creatures. But I had forgotten that during this time we don’t feed daily. More like once every 2-3 days

So my hypothesis for how the worms survived is that the relatively fewer numbers of worms to the bedding allowed them to get at least the minimum nutrition they needed from whatever of the paper was dissolved in the water and ambient microbes initially till the paper became more edible. Not likely to be as much as they needed (even a third of the weight of one worm would be unlikely to be floating around in sizes they can swallow in a fresh bin of wet tissue paper), but it was enough for survival, even if not eating to capacity (which is what you aim for in a vermicompost bin)

Will be interesting to see if the paper diet is nutritionally adequate by observing reproduction. An adult earthworm produces 3 or so cocoons per week and each cocoon has 2-4 hatchlings. Basically a single earthworm producing 9 future worms a week (though there must be two worms to reproduce) that will hatch and mature over the next 2-3 months. In healthy bin, earthworm numbers double in 2-3 months easily. If the earthworm culture is now over 2 months old, early hatchlings will be starting now. The next 2-3 months should show a dramatic increase in numbers if they are reproducing well.

With a single worm producing around 10 worms a week give or take, you can see how a few earthworms can colonize pretty much any size of a worm bin in a matter of months, their numbers continuing to grow while space is available.

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Two species of earthworms were used to unravel why some earthworm species crawl out of the soil at night after heavy rain. Specimens of Amynthas gracilis , which show this behavior, were found to have poor tolerance to water immersion and a diurnal rhythm of oxygen consumption, using more oxygen at night than during the day. The other species, Pontoscolex corethrurus , survived longer under water and was never observed to crawl out of the soil after heavy rain; its oxygen consumption was not only lower than that of A. gracilis but also lacked a diurnal rhythm. Accordingly, we suggest that earthworms have at least two types of physical strategies to deal with water immersion and attendant oxygen depletion of the soil. The first is represented by A. gracilis ; they crawl out of the waterlogged soil, especially at night when their oxygen consumption increases. The other strategy, shown by P. corethrurus , allows the earthworms to survive at a lower concentration of oxygen due to lower consumption; these worms can therefore remain longer in oxygen‐poor conditions, and never crawl out of the soil after heavy rain.

This is a paper tell us about the different strategies they can use to survive during the rainy season and that can justify the observation made by @Vidyut I guess…

Reference Role_of_diurnal_rhythm_of_oxygen_consump.pdf (210.2 KB)

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This is another paper which state that movement can also be somewhat influenced by light availability…

Recent work concerning the behavior of earthworms has related chiefly to their reactions to light. Since the contributions of hofmeister and Darwin, and that of Hesse there have been
a group of recent papers by Parker and Arkin, Miss Smith,Adams and Holmes, which have been devoted chiefly to the directive influence of light. In the present state of the discussion
of this subject the current theory of tropisms has been called in
question, according to which the earthworm is oriented directly
by light. Holmes has shown that light induces a general state
of activity leading to random movements of which those toward
the light are checked and those away from it continued, this
resulting in final orientation.
This paper aims to show that random movements are a feature
of less strong light, tending to disappear with the increase of
intensity, and are replaced by direct orientation in very strong
light. It is also shown experimentally that the earthworm is more sensitive in the extended than in the contracted state’and
that this has an important bearing upon the production of random
movements. The explanation given of this is that when extended
the sensitive elements of the skin are expanded over a gre’hter
surface. This is shown to have a bearing upon the production of
random movements as follows: Locomotion consists of a succes
sion of extensions and contractions and as each extension begins
in a state of lower sensibility the anterior end may be projected
toward the light, only to be checked when its increase of sensi
bility with extension makes the stimulqs appreciated. Movements
away from the light are not so checked. In stronger light the
sensibility of the worm when contracted is sufficient to suppress
movements toward the light at the outset. In such light the worm appears to be orientated without trial movements. It is
important that the worms be kept in the dark before all experiment as their discrimination diminishes and random movements
begin again when this is the case.

1535582.pdf (597.8 KB)

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@bivasnag there is no doubt that there is varying tolerance to moisture and being wet/submerged and that worms that find it too wet escape to higher ground. However, that doesn’t explain why they would try to escape the bin BEFORE it rains or for example for worms to try to escape a worm bin - which is like a box or some kind of closed container where it never rains. In both cases, the worms move without being rained on.

Worms move from the bin for a lot of reasons, but this was the one I found inexplicable. For example if temperatures are too hot, and the worms can’t get sufficiently cool by digging into the bin, they will try to migrate. Same in the case of overpopulation or lack of food. If bin is too wet, they will try to climb up and out. These causes are obvious. Other adverse conditions don’t result in escapes as much - for example a dry bin. They stay put and find humid spots - they don’t move out. But with the “before rain” escapes, nothing had changed in their bin. All of a sudden I had escapees.

Curious to see how many others have observed this, I did a casual search and found more observations from vermicomposters about their response to barometric pressure though nothing on humidity (not surprising, since the humidity in their microclimate will always be close to 100%).

Partial quote from one comment I found particularly interesting that discusses several reasons for worms to surface:

The most popular threory, and the one likely applicable to the greatest number of species is that worms, being 75% water but having a gas permeable skin layer require very moist conditions in order to thrive. What better time to forage for food and a date on the soil surface than when it is rainy and dewy? Behaviors and surface activites strongly suggest that worms are typically drawn to the surface when it’s wet rather than being driven there by some sense of threat.

Earthworms avoid high concentrations of CO2 and heavy rain events can slow O2 diffusion in saturated soils. This can leave the soil with higher than normal CO2 levels, leaving one to surmise that, in some cases, worms may be coming to the surface in search of some fresh air. Most soils, even when wet, are pretty well oxygenated, however (and rain water is pretty highly oxygenated water!), so it’s unlikely that CO2 avoidance is the dominant reason for mass surfacing.

When barometric pressure changes very rapidly worms tend to react by crawling up. Up to what is not apparent, nor is why, though I think Bryan’s theory of sensing potential threats in a way we humans cannot is interesting. A few years ago we had a typhoon here in the PNW during which the barometric pressure was measured at the lowest in recorded history. We documented worms massing up the sides of buildings and tree trunks. Very low pressure can mean a LOT of rain, and even our soils have their field saturation limit. Perhpas the worms recognize that rapid pressure change can mean the potential for rainfall events if biblical proportion? Why not!

From here: Foul Weather Worms

Interestingly, a comment before this one also mentions a nightcrawler surviving for 2 months in pure water (not even tissue paper!) - so how long an earthworm can survive without feeding also may be species dependent with some species clearly having very long endurance.

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This comment from an expert is sceptical of the barometric pressure theory and does evaluate the comment mentioned in my previous post. Worms and Barometric Pressure - Red Worm Composting

Both the persons in question are seasoned vermicomposters who have conducted their own experiments of various kinds as well as have professionally raised and sold both earthworms and vermicompost (and compost bins/designs). He seems to see humidity as a factor in attracting the worms out, which also makes sense. High humidity will mean that the worms can venture out of the worm bin without risk of drying. Though I am not very convinced of this answer, as the worms that land up on the kitchen floor often do exactly that - die - unless I find them and return them to the bin in time.

Whatever it is, the response of earthworms in a worm bin to rain is fascinating, because they are responding to one or more conditions associated with rain without actually getting rained on.

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So what we are focussing on is it like why earthworm coming up, is there a role of barometric pressure on the locomotion of earthworm @Vidyut

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Yes. I thought it would be interesting to find out. Though I wonder how such an experiment could be set up to alter barometric pressure. Alternatively, it could mimic natural conditions better to keep a record of barometric pressure and see if there are corelations with pressure or rapid change in pressure with the escapees.

I haven’t thought that far ahead, but seems logical to alter pressure and see if any change in earthworm behavior or to note pressure just before and during earthworms spontaneously attempting to escape.

And as I type this, a question comes to mind - are the earthworms merely rising or escaping (as us vermicomposters perceive it)? As in, are they simply coming up or wandering to another location ro actively fleeing the bin? Or even merely attempting to rise to a certain height automatically takes them out of the bin which is shorter - as in they may simply want to get higher, not necessarily exit the conditions of the bin. Many possibilities. Who knows what goes on in their heads…

Edit: Wanting to get higher, and not necessarily escape the bin has some behavioral evidence. When there are a few worms escaping the bin, there can often be entire thick ropes of them clustered at the very top - the highest they can get - without exiting the bin. Very creepy, that can look.

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That’s great I was reading a similar paper on c elegans as I am working on C elegans in CUBE

As the abstract read- The mechanical properties of cells and tissues play a well-known role in physiology and disease. The model organism Caenorhabditis elegans exhibits mechanical properties that are still poorly understood, but are thought to be dominated by its collagen-rich outer cuticle. We use a microfluidic technique to reveal that the worm responds linearly to low applied hydrostatic stress, exhibiting a volumetric compression with a bulk modulus, k ¼ 140 5 20 kPa; applying negative pressures leads to volumetric expansion of the worm, with a similar bulk modulus. Surprisingly, however, we find that a variety of collagen mutants
and pharmacological perturbations targeting the cuticle do not impact the bulk modulus. Moreover, the worm exhibits dramatic
stiffening at higher stresses—behavior that is also independent of the cuticle. The stress-strain curves for all conditions can be scaled onto a master equation, suggesting that C. elegans exhibits a universal elastic response dominated by the mechanics of pressurized internal organs.

May be similar type of response could be the reason for the earthworm to crawl up… @Vidyut

Referencemmc2.pdf (2.2 MB)

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The problem I see in your long engagement @Vidyut is that you go on and on with no worry of offering authentic references !
We like engagement…But, we are in evidence -based Science! Hope, you understand our anxieties!

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Thanks @bivasnag for providing reference in favour of your argument!
Hope, @Vidyut follows this.

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Please post the Corrections in bold and make them separately crisp for all to take note of @Vidyut

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Scientific Methodology and our engagement in STEM Chat:
“…Occam’s Razor instead is saying that when presented with competing hypotheses that make the same predictions, one should select the solution with the fewest assumptions[[1]]…”(https://en.m.wikipedia.org/wiki/Occam’s_razor#cite_note-:0-1)

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Earthworms…" Because some earthworm spe-
cies have been demonstrated experimentally to have a diurnal rhythm of oxygen consumption, with a high rate of consumption at night and a low rate during the day (Ralph 1957; Chuang et al. 2004), we suspected that the reason for earthworms leaving the soil may be
their rate of oxygen consumption and tolerance of water submersion. On the other hand, because earthworms live in the soil, their physical condition andcrawling behavior may be affected by chemicals entering solution, such as acid (soil pH) or heavy metals
(Chen & Liu 2006), in flooded burrows (Gupta et al.1999; Spurgeon et al. 2004)…"

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The above quote is from the link given by @bivasnag: https://stemgames.metastudio.org/uploads/short-url/qgw3WzCzxqcoUzG4g1YZoruskhj.pdf

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The difference in the citations by @Vidyut and by @bivasnag is that in the latter articles, there are cross-references to counter check the veracity…!
@Vidyut we hope you will agree that there should be some criteria like cross-references for countercheck and verification, lest it will be one’s belief vs another’s!
The scientific method demands the approach of @bivasnag. Hope, @Vidyut will agree!

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