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Arion species (unidentified)

This slug is so long and extensible - elastic! When resting it has a usual Arion shape, and can hump itself up into a rectangular lump when disturbed (which Arion circumscriptus cannot do), but while crawling, it just stretches longer and longer! In order to show an average aspect, I don’t paint my slugs fully extended, so this portrait does not show this beast at its extreme, which is at least another 5 mm. It is not particularly shy, willing to wake up and walk about when nudged gently, or when its substrate is tilted or rotated. It had two wounds made by the fast, agressive little Deroceras panormitanum - luckily on the left side, as my portrait is of the side with the pneumostome. When I first opened the lid upon receiving the parcel from Washington state, I noticed one of the Deroceras following a slowly crawling Arion, and biting its tail! I immediately found several plastic sandwich containers and began to isolate all of the Deroceras, one to each box. I selected the largest Arion to begin painting, leaving the others in the thermos jug they were shipped in.

On March 14 I wrote to my family:

“Well, after a full day of painting, beginning at about 11:00 am, and finishing around 10:00 pm - I have the “mystery slug” painted, very frustrating because it wasn’t even on my list of species for the book, and we’re so close to the deadline. I couldn’t leave it until after the deadline, however, because the nasty little dragon-slugs Deroceras panormitanum, which it was shipped with from Washington state, had taken chunks out of its left side and tail fringe, and that might have compromised its health in captivity.

Love, Aleta”

Arion circumscriptus

distinctly black-speckled, tan-to-grey mantle & back
dark reddish-black tentacles
sides neutral pale grey
mantle sides tannish grey below lateral line
foot wide (spindle-shaped body)
foot pale grey
foot fringe very pale yellow
tail abruptly tapered to a point

These are the characters I noticed as I was painting this shy, gentle slug, not yet quite sure of its identity. Sometimes it is good when one hasn’t put a creature “in a slot”, because then you take more careful note of everything about it. This is definitely Arion circumscriptus according to my slug experts Bill and Robert.

The Arion circumscriptus were all smaller than the slug I’d just painted, and they rested on a wet surface with their foot fringes spread out in a skirt, giving their oval bodies almost a limpet shape. They were also liberally freckled with black. When I finished the portrait of the large slug (which I am calling the “Mystery Arion”) and began to draw the Arion circumscriptus, I was impressed with its shyness. Prodding it never resulted in a resumption of activity. I just had to wait, tilting the substrate gently, and holding it under the light. The shy little slug eventually decided to get up and move to a more peaceful spot, and so I got to photograph it, and to watch it closely to paint.

Next I painted the Deroceras panormitanum that had been chasing my poor Arion circumscriptus around and taking bites out of it.

Deroceras panormitanum

March 19:

I made some interesting observations while working with these slugs (I used two of the four you sent (one died upon arrival, and was preserved promptly).

Although they are sluggish on damp leaf litter in their containers, these “racing slugs” become very active, and ‘run’ very fast when put on a foreign substrate, like the flexible plastic ruler I use while painting. During the course of the “live sitting”, I can’t take my eyes off one of these fast slugs for more than a few seconds at a time, because it creeps about a centimetre per second toward the edge and drops off. A couple of times, when ambling rather than running, D. panormitanum has gone over the edge leaving a strand of slime attached to the edge, and dangling head-down, descended slowly.

The first time, the slug slowed to a stop at about 10 cm below the edge of the ruler. After waiting for about a minute, twisting and spinning slowly only 3 centimetres above a lettuce leaf, cupping its foot so that the fringe edges looked like the blades on a weirdly flexible bobskate. Then it began to swing its head and neck from side to side in “U” shapes 8 or 10 times, before making contact and climbing up its own body and then up the slime strand, which by this time had dried and become very thin, like a single strand of spider silk. It climbed up the strand, rather than eating it, and in about 15 seconds, was up over the edge of the ruler.

The second slime-strand was much longer, measuring about 25 cm. I had someone hold the ruler for me as I tried to get some photos, but the slug was swinging and the camera wouldn’t focus on it. This time the slug dropped a few centimetres to the dark blue tablecloth, rather than climbing back up the strand.

These “racing slugs” run very far on the flexible ruler during the course of painting, and when they begin to look a little dry and desperate, I give them a rest in their container while I continue to paint, referring to photos, or take a break myself.

On one of these occasions the slug had made a dash for freedom just as I pressed the lid on its container, and got trapped in the groove of the lid for twenty minutes or so, until I opened the container to resume painting. The poor slug looked rather deformed, but it straightened itself out somewhat as it crawled slowly under a leaf, so I left it to rest for a few hours. On checking it later, I noticed it curled in a “U” shaped position, and then it reached for the side of its tail and began a licking motion. After 7 or 8 ‘licks’ it turned away, and there was an opening in the previously unbroken brown skin, a fresh gap about 1.5 mm long, revealing the translucent grey flesh beneath. My best guess is that the slug had excoriated its bruise - if it were not mistaking its own side for the wounded flesh of another slug, it was perhaps aiding its own healing by making a fast-healing cut where there had been a slow-healing bruise.

This afternoon, as I packed the slugs up after finishing the painting, I peeked inside each apartment. I was pleased to see the wounded slug looking plump and active, albeit with a slightly shortened and dented aspect to the left side of its tail - the wound appeared to be healing over. In the second slug’s container, where it rested in the dark damp space between two dead leaves, there were about 15 newly-laid eggs, clear as glass. Peeking again at the wounded slug just before closing the lid, I noticed a tiny, slim figure of a minute slug, only 1.5mm long - a greyish pink baby Deroceras panormitanum (couldn’t have been an Arion, as their hatchlings are quite plump). It was crawling quite quickly, so I reached for my camera, but by the time it was turned on and set to macro, the little one had disappeared. Racing Slugs!

Later I wrote to Bill Leonard:

“It is difficult deciding on an aspect for a slug, when it looks so different when first discovered, slippery with slime, and when its been crawling and dry. Also, whether it’s contentedly moving, or dashing, neck full out. My mental image of D. panormitanum now, after having spent so much time with it, is different than I have it in the painting. It is reaching, neck arched like a little racehorse, tentacles stretched to thinness, and foot narrowed for speed. Quite a different aspect than the placid one I have painted. That’s why I particularly wanted to see if you recognized its likeness in the painting”. (He answered that the position I have painted it in is recognizable and quite appropriate.)

Ariolimax columbianus

Jane, our intrepid British Columbia slug hunter searched for the alien Worm Slug (Boettgerilla pallens) without success on Vancouver Island this fall, but she did capture a native Pacific Bananaslug (Ariolimax columbianus) in Vancouver. She made a liason with the Malacologist Robert Forsyth at the Vancouver airport, just as he was about to board a plane to Ottawa to attend COSEWIC (Committee On the Status of Endangered Wildlife In Canada) meetings, and slipped him the container, which he carried onto his flight and passed to me as I met him at the Lord Elgin Hotel. The giant slug (120 mm) was alive and well, though it had thoroughly slimed up the moss and paper towel in its container.

The skin of this beast is amazingly slick. Although the body has longitudinal grooves, they are finely incised on a smooth flat surface, nothing like the tubercular ridges of Limax maximus. The colour is like green pea soup, except that the foot fringe pales to yellow toward the front. Most Ariolimax have black spots. This one is unmarked, even lacking the usual black marking in the centre of the mantle. On Vancouver Island we found the Bananaslugs wildly variable, from the usual olive green to white - to orange sherbet coloured, with varying amounts of black, some spotted like pinto ponies! Sorry to paint such a dull one for you - but not sorry to have made the close aquaintance of another giant slug, whose facial expressions are ever changing, and who on more than one occasion raised its head up, eye stalks straining, “the better to see you with, my painter”.

Large invertebrates always amaze me, whether they be crayfish or starfish or clams or slugs. As highly visible representatives of the overwhelmingly vast and diverse world of tiny invertebrates, they give me an insight into their feelings and make me feel very small in the face of their giantness. It’s a strange sort of inside-out feeling!

This is one of my favorite plein air oils, painted in the fall of 1992, while sitting in the moss in a bog south of Cochrane, Ontario. It took two afternoons. We were camped nearby on a closed loop of the old highway.

Bogs are exhillarating places for me - the sharp acidic smell of the sphagnum, the clean cushiony texture of it, the rich contrasting reds, oranges and greens of the moss itself… the visual excitement of the tracery of Cranberry over the sphagnum. The micro-topography of a bog is interesting, in contrast to its flat aspect from a distance - it is always hummocky, and the little pools of black water are like reflective jewels in settings of brocade and filigree. The stunted aspect of the trees, and to realize that they can be centuries old and no taller than myself, is very personal somehow. I admire the tenacity and hardiness of the few plant species that can survive in bogs - and that most of them are evergreen. The plants that survive in the sterile acidic matrix of Sphagnum can only do so by special adaptations, like those who keep microrhizal fungi on their roots, to digest the moss and release nutrients - and the exotic-looking Pitcher Plants which collect their own food by drowning insects. The simplicity of there being so few species that I can know them all, is also personal. Where else can you be and know the names of everything you see around you?

Deroceras reticulatum

I have just finished the third dorsal view of this ubiquitous slug introduced from Europe, Deroceras reticulatum, the milky-slimed muncher in every garden, variable in colour and fast moving. You can see the flat spot in the rear portion of its mantle, where the vestigial shell sits, internally. The finger-print wrinkles are slighter just over this bit of shell that reminds us that slugs are relatives of snails. It has two characteristics that make it easy to tell apart from its native cousin D. laeve. D. reticulatum has a large pale area surrounding its pneumostome, or breathing hole, and when the animal is touched, it exudes exceedingly sticky white mucous which is hard to get off your hands, and can cause dermatitis in the slug collector.

The lateral view and first dorsal view were painted from a 45mm individual collected by Judy Courteau, from under an Elm tree near Dunville, Ontario, on 23 September. The second dorsal view was collected by Fred, from under the “Novisuccinia board” here in Bishops Mills, field number 2008/279/db, and the third dorsal view (the pale one) was collected by Judy in the spring, from a greenhouse in Smiths Falls.

Deroceras laeve

is native, a feisty little slug. It moves even faster than D. reticulatum, having a very narrow foot on which it practically runs about, sometimes chasing other slugs and biting their tails. It is more or less dark brown with chestnut mottling, especially on the mantle, which is boldly wrinkled - but from above and without magnification, it appears black. When disturbed, it exudes a clear mucous which seems to fill in all the wrinkles and make its body appear smooth and shiny. The pneumostome is not as noticeably pale as it is in D. reticulatum. The individual I painted here is 28mm from head to tail, and was collected by Judy Courteau on 17 September at Highway 90, east of Angus, Ontario.

Pallifera dorsalis

is a tiny native slug of forests east of the prairies. On close inspection it is unmistakeable, having a smooth (very slightly wrinkled) gray mantle covering its entire body, from head to tail. The eye stalks are darker, and the front of the foot, near the mouth, is rusty coloured. This individual, 12mm from head to tail, was bluish-gray when it was taken into captivity at Little Cove on the Bruce Penninsula, by Matt Keevil. For the first week it did not stray from the little piece of moss that it had been collected with, avoiding the scrap of Romaine lettuce that is the fare of all of our captive slugs. But after a week or so it began to eat the lettuce, and by the time I got around to painting it, its body colour had changed from blue gray to more of an olive gray. I made a compromise and painted it somewhere in between.

Arion intermedius

is another small slug, delicate, yellowish with tints of blue, a yellow foot, faint lateral stripes, and black eye stalks which give it the classy aspect of a siamese cat. Along with the other Arion slugs, it is an European immigrant. The few individuals that we caught on our trip in August of this year (at least two localities) are the first slugs of this species recorded in Ontario outside of greenhouses. They may have been “naturalized” for decades, but being easily overlooked, and since the landscape was not crawling with malacologists, they were not reported until we discovered them. Robert sent me one from British Columbia (where they live along the coast) earlier in the summer, but it must have either perished or been eaten by one of the larger slugs, because I searched through its box in vain. I was very happy to have this one to paint, 25 mm in length, and collected near the Durham Conservation Centre, West Grey, Grey County, Ontario. As I painted its portrait, I delighted in its unique aspect and charming habits - one of which was to curl up like a cat, head to tail, to have a nap. When disturbed, it assumed a classic Arion hump-shape, which I have also painted here.

Arion distinctus

This slug we suspected is Arion hortensis because of its orange foot, placement of lateral stripes, and dark colour. Robert decided that it is Arion distinctus, in the A. hortensis species group. It is 40 mm long, which is the maximum length of the species, according to the European Land Snails book. It was collected by Judy Courteau from a greenhouse on River Road in Ottawa, another European introduction. Like Arion intermedius, it also curls up like a cat, head-to-tail, to sleep between meals. It hollowed out the yellow snap bean, favours the green ones less well, but avoids Romaine lettuce, which is a favorite of most of our molluscan guests.

Arion fasciatus

from Coburg, Ontario, is 50mm long from tiny dark head to the tail at the end of its exceedingly extensible body. When it was crawling fast, it just got longer and thinner like an earthworm, at least 15mm longer than the position in which I have portrayed it. The yellow tint below its lateral lines is a diagnostic feature, as is the pale yellow foot.

The Giant Garden Slug, Limax maximus, has charmed me again. I haven’t seen one since I was four years old, in Seattle, Washington. The subtle colours, the handsome spots and stripes, the graceful reaching, tentative progress, delicate cool touch - I’ve been enthralled and delighted all over again as I turned the scrap of dampened board this way and that to orient the creature according to my painting as it crawls, like the Red Queen in Alice in Wonderland…. faster and faster just to stay in the same place. This individual was collected along with a young one, in a tangled copse of mixed woods in a town on Georgian Bay named Dyers Bay on the Bruce Penninsula, Ontario, in August of this year. This marvelous mollusc is about 12 centimetres fully extended, and I think it is not quite full grown!

Prophysaon andersonii, one of the tail-dropping slugs from British Columbia. 50mm head to tail. You can see the change in texture , diagonally, about a quarter of the way forward from the tip of the tail. I didn’t challenge it to drop its tail, for obvious reasons.