Sunday, 24 February 2019

Jumping Jiminy! It's Spore-eating Snow Flea Season!

Snow fleas look like hopping black specks 
in the snow (Rolf Schlangenhaft)
Though there's still two feet of snow covering the forest floor, there are signs everywhere that spring is on its way. Chickadees have started singing their mating song! The warm sun is tatting lace into south-facing snowbanks! And sunny depressions and ruts in the snow are liberally sprinkled with black pepper! But, wait a second...why would there be black pepper on the snow? And why is that black pepper JUMPING??

Close-up, tiny snow fleas have a blueish cast. 
The first time I found these leaping blackish blue dots in the snow, I had no clue what they were, so I called them snow fleas—which it turns out is what everybody else calls them, from Russia to Sweden to France— though they're not even remotely related to fleas. What they are is a very interesting type of springtail. 

Springtails are very cute little guys that, though they have six legs like insects, are nonetheless different enough that they're not included in that class: among other little quirks, they have fewer abdominal segments, lack proper compound eyes, and shed their exoskeletons throughout their lives. They also have a special way way of jumping. 

Sminthuridae springtails are even cuter 
than snow fleas (Tim Evison/Wikipedia)
Almost all springtails have a tail-like appendage on their abdomen called a furcula. This little device—the biggest springtails themselves are only 3mm long—is folded under the creature's belly and held there under tension by another structure called a retinaculum. When this click mechanism is triggered and the furcula snaps against whatever a springtail is sitting on—be it twig or fallen leaf or crust of snow—the tiny little guy is flung into the air. Kind of like the action of an old tin click toy. This makes it fun to poke your finger into a clutch of snow fleas, which makes them all trigger their devices at once. 

Remember these?
Sadly, springtails have no aiming ability, so they don't have much choice in the direction they go, but the quick random "boings" can be enough to keep them out of the mouths of predators.

Springtails are mini garburators that help to make soil by eating decaying organic matter, algae, fungi and fungi spores, and poop—which is sometimes their own. Thousands can be rummaging though the moist forest floor litter at your feet, but are usually not noticed because they're so incredibly tiny.
In the winter, snow fleas eat spores that accumulate on the surface of melting snow. Spore pickings are rich in the winter since there are many species of fungi that are not only cold tolerant, but that actually thrive in the winter and produce spores when temperatures rise a bit above freezing. These include numerous perennial polypores, resupinate crust fungi, and jellies.

Snow fleas chowing down on Fomes fomentarius spores in January.
No one knows exactly why snow fleas creep up through melting channels in snow to the surface on warm days at the end of winter, but the fact that these minute "cold-blooded" creatures are capable of such activity in cold temperatures when other over-wintering insects remain dormant has interested researchers for a long time.

Thousands of snow fleas in tire ruts in snow... 
...or in crevices. (both photos Rolf Schlangenhaft)

A couple of these researchers, Laurie Graham and Peter Davies of Queen's University have isolated a protein from snow fleas that acts like antifreeze in their bodies. Though there are a number of different animals that have evolved proteins that protect their tissues against the nasty effects of freezing, including the woolly bear caterpillar and the grey tree frog, two characters featured in my kids' book, Winter's Coming: A Story of Seasonal Change  about animals preparing for winter, the protein found in snow fleas, has a novel, and possibly very useful characteristic that other animal "antifreezes" don't have: at higher temperatures they break down. The exciting possibility is that this protein might be of use for organ transplants, which could not only be kept colder, and therefore stored longer than they can be now, but also, when the organ is finally used, the protein will be cleared from a patient's before harmful antibodies can form.  

When there's no snow, snow fleas can be found in forest litter.


Graham, L.A. and Davies, P.L. (2005) Glycine-rich antifreeze proteins from snow fleas. Science 310, 461.

Saturday, 13 October 2018

Ode to a Mushroom (and to Wrinkled Mushrooms and Vernal Ponds): Bolbitius callisteus (B. callistus)

Bolbitius callisteus - baby & young adult

Bolbitius callisteus, a.k.a. B. callistus, is one of my favourite mushrooms – for a whole bunch of reasons. And edibility is not one of them.

Reason #1:

It's a trickster, in that it looks completely different at different stages of its existence. It starts out as a greenish button, with pale greenish yellow gills, then spreads into a licked butterscotch candy parasol – often the same day. If you find representatives of these different stages in different locations on different days, which seems to be the norm since they often grow solo, you'd be hard pressed to consider them to be the same character. At least, I was. 

Young gills with green tones 
Even the stem of the young one has greenish-blue tones, 
tones that can disappear in a matter of hours.
Licked-candy stage

It soon becomes heavily striate.
The caps of old specimens become conical. The stipe 
also darkens, as do the gills as they're 
coloured by reddish brown spores.

In the plant world, coltsfoot is a classic example of such trickery, though this wildflower/herb takes it a step further – or maybe backwards. First it produces dandelionish flowers that push up from the ground in early spring without any sign of accompanying leaves. Only later, after the flowers have withered away, do the oversized leaves finally break through the soil and unfurl. An old name for it was actually Filius ante patrem – son before father.
Since Coltsfoot (Tussilago farfara) flowers and leaves appear at
separate times, you'd be forgiven if you thought they were two
different species. (Photos: left
Andreas Trepte, right Wikipedia)

Reason #2:

Bolbitius callisteus has an affinity for growing on fallen hardwood limbs and branches that have been water saturated for part of the year. The best place to find these branches is in vernal pond areas. 

Vernal ponds are spring ponds, fed by snowmelt and rain, but without any outflow. I'm fond of these ponds and the dips in the forest that are revealed when the water evaporates or soaks in. They're the chameleons of the forest ecosystem. In April, they're like any other spring pond, attracting ducks during migration. In May they're all quacky – not with ducks, but with the mating calls of wood frogs. Because these ponds usually appear in low, poorly drained areas, the soil has a tendency to remain moist long after visible water has disappeared. Even during droughts – which are becoming more and more common in southern Ontario – these areas continue to produce fruiting fungi.  

Vernal pond in April
Vernal pond in early March after a dry winter
A different March vernal pond
Vernal pond in May
Vernal pond in June
Centre of a large vernal pond in September (with leaping Ruby)
Vernal pond in October – note the 
spring waterline on the tree trunks

Reason #3

Bolbitius callisteus is supposed to be very rare. Asterotus/Resupinatus dealbutus, which I wrote about a couple of months ago, was also found in vernal pond areas and is also rare. I like finding "rare" fungi since they usually don't show up in field guides, which makes them a challenge to identify. Dried up vernal ponds are a great place to look for rarities. Here's a selection of my local ones: 
The aforementioned Asterotus/
Resupinatus dealbatus that has its own post.
Arrhenia retiruga. The middle specimen is upside
down, showing its gill-less fertile surface.
Clavaria rosea – the subject of my first, very dull, blog post
Hygrocybe coccineocrenata ss. auct. amer. 
Caulorhiza hygrophoroides, which has a long
pseudo-root – so long that I couldn't get all of it.
Baeospora myriadophylla
I question, though, whether these fungi are actually really rare, or simply rarely collected. Human-made paths normally, and sensibly, skirt around seasonally flooded areas, so maybe these areas are just not as frequently scoured by collectors. They can be certainly be unappealing areas when prickly ash is involved (I have thorn scars to prove it).

Reason #4 

I have a soft spot for wrinkles and reticulation, and not only on mushrooms. I have always loved the wrinkles of my straightened elbow, and of the straightened elbows of people I love. So pliable! So playable! So hard to see (on myself)! And the caps of Bolbitius callisteus, when young, are wrinkled and/or reticulate (netted or veined).

Bolbitius casteneus is wrinkled, though often not spectacularly so. 
Fungal wrinkles and reticulation are not uncommon. Lots of boletes, including a number of choice ones, have reticulation on their stipes that can help in their identification. 
Boletus chippewaensis, my local King Bolete, can
have anything from a light netting at the very top of its stem
to head-to-toe reticulation, 
like a crinoline glued to it.
The queen of the boletes with reticulate stems has to 
be Frostiella russellii/Boletellus russellii 
with her deeply carved reticulation.
A friend said its stem looked like a Cadbury Flake bar.
I knew there was something in my past that made me salivate
the first time I found a Russell's Bolete!

But what I like most are mushroom caps that have wrinkles or reticulation – like the cap of Boletus callisteus's brother, B. reticulatus, which is named for this phenomenon. 

Bolbitius reticulatus often has a pretty violet tones.
The cap of B. reticulatus is covered with a viscous coating that 
makes it hard to photograph its wrinkles. See Mycoquebec 
for much better images and full description.
Like B. callisteus, B. reticulatus becomes strongly 
translucent striate as it opens. 
Sometimes there are no violet tones at all.

Cap wrinkles are also common in many Pluteus species (pink-spored, free-grilled mushrooms that grow on wood)
Pluteus granularis with guttation-droplet jewellery 
Pluteus chrysoplebius can be deeply wrinkled when young. 
Pluteus thomsonii – the prince of Pluteus reticulation
Here's a few more: 
Psathyrella delineata – The Wrinkled Cap Psathyrella
The Gypsy Mushroom – Cortinarius caperatus
And I'd be remiss not include the craziest reticulate cap of Rhodotus palmatus

Reason #4

Pure aesthetics. I think this mushroom is gorgeous. I can never resist taking out my camera. 

See Mushroom the Journal for definitions of various terms for forms of wrinkles on fungi.

Unless otherwise noted, all photographs © Jan Thornhill