Spiderday (#27)

I know, I know… it’s been too long since the last SPIDERDAY post! The end of term proved busy, but I’m trying to get back on track. So: here are some of the best arachnid-themed stories of the past couple of months. I hope you enjoy all the eight-legged greatness! Let’s start things off with a beautiful photo:

Zora hespera, photo by Sean McCann

Zora hespera, photo by Sean McCann

Jumper_Art

 

Spiderday (#26)

Finally, SPIDERDAY is back! (Sorry about the delay – it’s been a busy term, so I’ve not been able to keep up on the blogging). Here are some Arachnid-themed stories pulled from the web over the past month or so:

Two of my favourite Arachnologists (Sean and Catherine) have been on a great SPIDER TRIP adventure! This is one of the species they stumbled across in Texas. Yes, it's a brown recluse (photo by S. McCann).

Two of my favourite Arachnologists (Sean and Catherine) have been on a great SPIDER TRIP adventure! This is one of the species they stumbled across in Texas. Yes, it’s a brown recluse (photo by S. McCann). Check out more photos from their adventure, here.

Capture

Bog spiders: family composition and sex ratios

This is the second post by Honour’s undergraduate student Kamil Chatila-Amos – he has been busy working on identifying LOTS of spiders from bogs of northern Quebec. His first blog post introduced his project: this one gives a glimpse into the data…

My project is focused on studying spiders from bogs in the James Bay region of Quebec. Five bogs along the James Bay highway were sampled with pan traps every week for four sampling periods. In the full project I’m looking at how abiotic factors (i.e. pH, water table, latitude, etc.) and the plant community affect the arachnid community composition. For now, let’s look at how the spider families are distributed in these sites:

bogSpidersThe first thing that might strike you if you are familiar with the area and its spider fauna is that in 4 out of 5 sites, neither Lycosidae (wolf spiders) nor Linyphiidae (subfamily Erigoninae) are the most abundant family. Previous studies in similar habitats tend to find a much greater proportion of those two taxa (Aitchison-Benell 1994; Koponen 1994). All sites except the first have more Gnaphosids than Lycosids. However, the breakdown within families is very different. Whereas the Lycosids are represented by 19 species, there were only five species within the Gnaphosidae. Even more impressive is that one Gnaphosidae species represents 99% of the family. Indeed, Gnaphosa microps alone represents a fifth of all arachnids I collected.

I’ve come to like Gnaphosa microps a lot! The family Gnaphosidae is pretty easy to identify thanks to their long and separate spinnerets, colour and eye placement. Even the palps, which are unique to species, are fairly easy to recognize. It ranges in size from 5.4 – 7.1 millimeters which is a large enough size so it isn’t a hassle to manipulate.

Gnaphosa microps, seen from above. Photo from the Biodiversity Institute of Ontario through Barcode of Life Data Systems

Gnaphosa microps, seen from above. Photo from the Biodiversity Institute of Ontario through Barcode of Life Data Systems

Gnaphosa microps is by no means a star of the spider world but we still know a fair bit about it. It is a holarctic species meaning it can be found in almost all of the northern hemisphere, even as far as Turkey (Seyyar et al. 2008). It is usually found in in open boreal forests, alluvial meadows and bogs. A nocturnal species, it spends its days in a silk retreat under moss or debris and hunts at night by catching prey on the ground (Ovcharenko et al. 1992). Even though sampling has been done very near my sites and in similar habitats (Koponen 1994) I still haven’t found another study where it was the most abundant species.

Another interesting tidbit about this species is just how skewed their sex ratio is. According to my data, males outnumber females almost 10 to 1! Now this does not mean it is always like this in nature, this ratio can be explained by sexually dimorphic behavior. This means that the males would behave differently than females in a way that would increase their odds of falling into traps. Indeed, according to Vollrath and Parker (1992) spider species with sedentary females have smaller, roving males. And like their model predicts the G. microps males are a bit smaller than the females.

Sex ratio of Gnaphosa microps, collected in bogs

Sex ratio of Gnaphosa microps, collected in bogs

 

So what’s next? I still need to retrieve the COI barcode of all my species and that will be possible thanks to the University of Guelph’s Biodiversity Institute of Ontario. This is to make sure my identifications are indeed correct. As a first time spider taxonomist it’s great to be able to confirm my work in a way that still is not widely available. Today I received the plate in which I’ll load the spider tissue and I am amazed at how tiny it is. I guess they just need 2mm per spider but I still expected it to be much more impressive. Hopefully I don’t get any nasty surprises once the DNA data comes back, although some of those tiny Linyphiids did give me a pretty bad headache…

Vouchers

References:

Aitchison-Benell CW. 1994. Bog Arachnids (Araneae, Opiliones) From Manitoba Taiga. Mem. Entomol. Soc. Canada 126:21–31.

Koponen S. 1994. Ground-living spiders, opilionids, and pseudoscorpions of peatlands in Quebec. Mem. Entomol. Soc. Canada 126:41–60.

Ovcharenko VI, Platnick NI, Sung T. 1992. A review of the North Asian ground spiders of the genus Gnaphosa (Araneae, Gnaphosidae). Bull. Am. Museum Nat. Hist. 212:1-92

Seyyar O, Ayyıldız N, Topçu A. 2008. Updated Checklist of Ground Spiders (Araneae: Gnaphosidae) of Turkey, with Zoogeographical and Faunistic Remarks. Entomol. News 119:509–520.

Vollrath F, Parker GA. 1992. Sexual dimorphism and distorted sex ratios in spiders. Nature 360:156–159.

A Tangle of Opiliones

The results are in!! Last week I ran a poll to get help in picking the best name for a congregation of Opiliones (i.e., Daddy long-legs, Harvestmenpersons). HUNDREDS of you voted, but the clear winner, with just about 55% of the votes is…

“A Tangle of Opiliones”

Opiliones

A congregation of Opiliones (photo by D. Ringer, reproduced here under CC License 3.0)

This name was proposed by “Antnommer” on Twitter, and it is quite fitting. When thousands of Opiliones hang out together, it does indeed look like a full-on tangle of Arachnids.

Thanks, everyone, for participating in the poll, and helping to find a perfect collective noun for these astounding Arachinds.

Here are the poll results, for those interested:

PollResultsAnd some of the “other” suggestions:

PollResults_Other

Here’s another video to illustrate a rather fine tangle of Opiliones

 

What do you call a congregation of Opiliones? (Poll)

The Arachnid order Opiliones are interesting animals, although vastly understudied. In the English speaking world, they commonly known as Daddy long-legs, Harvestmenpersons, or Shepherd spiders. Opilio, in latin, refers to “shepherd”, and many temperate/northern species have exceedingly long-legs, perhaps in reference to Shepherds on stilts, watching their flocks. The name ‘harvest’ likely refers to the natural history of some species who tend to see higher population numbers in the autumn (‘harvest’ season in the north). Many species are also known to form very dense ‘congregations’, sometimes numbering in the thousands.

Opiliones

A congregation of Opiliones (photo by D. Ringer, reproduced here under CC License 3.0)

I was doing a bit of art on the weekend, and was drawing such a congregation, and this led me to consider what to call a collection of Opiliones. There are great sites out there devoted to Animal Congregations, but none of them had a collective noun for Opiliones (spiders, by the way, are sometimes referred to as a clutter or cluster)

Time to change that. After some Twitter discussions, I present to you a Poll, and I am looking for your votes!

–POLL IS CLOSED—

A congregation of Opiliones.

A congregation of Opiliones.

I’ll leave this Poll open until around the 8 of March – and then write an update! Please share!

…for inspiration, here’s a video for you:

Spiderday (#25) – February

It’s that time again! Spiderday – your monthly linkfest of all the best Arachnid stories from the past month.  Let’s get started…

A wolf spider. This photo by Sean McCann related to some daydreaming I've been doing, about collecting spiders.

A wolf spider (genus Rabidosa). This photo by Sean McCann related to some daydreaming I’ve been doing, about collecting spiders.

Capture

Capture

The Arachnophile: hunting the wolf

Rabidosa

A wolf in the genus Rabidosa (photo by Sean McCann)

 

Hunting the wolf

 

In summer’s forest.

Armed with hand lens,

Forceps, vials, eyes and field book.

Up. Down. Under rocks, leaves, rotten logs.

Just look.

Behold! Scurry, pause, dash, dart.

Find that dark place.

All in eights: all is right.

Pedipalps and spinnerets; chelicerae and pedicel.

Chevrons? Eye shine? Perhaps a sac of treasures?

Pardosa, Trochosa, or Rabidosa?

Envisioning authors, keys, maps, habitus.

Line drawings come alive.

A marvelous wolf, hunted.

What a find! The Arachnophile’s delight!

Into the vial, destined for deep freeze.

Wait, think, imagine.

It is precious.

Not Tolkien’s monsters, or a reclusive terror.

It is Anansi, Charlotte, and Darwin’s gossamer.

Nature and natural.

History beyond our own.

Preserve? Conserve? Observe?

Catch, release, smile.

 

Agelenopsis webs

A hot, humid summer forest, with evidence of spiders.

 

 Notes:

1) The Lycosidae are impressive spiders, and go by the common name of “wolf spiders”. Here are some facts about wolf spiders.

2) This was inspired by daydreaming. Winter can be long and I’ve been thinking a lot about summer field work, and collecting arachnids in a hot, humid forest. I’ve been thinking about observing, collecting, preserving specimens. Bringing specimens back to a lab isn’t always necessarily. Sometimes watching is enough.

Spiderday (#23) – Happy Holidays

SPIDERDAY is finally back – it’s been a few weeks, but the end of the term has been hectic. However, it’s time to catch up on some great Arachnid-themed links from the last little while.

This will also be my last post of 2015, so I’ll also take this opportunity to THANK YOU for reading and commenting on this blog. I also wish everyone a Happy Holidays! Arthropod Ecology will certainly keep on truckin’ in 2016.

Here's looking at you... A close up of an Araneidae, from Insects Unlocked.

Here’s looking at you… A close up of an Araneidae, from Insects Unlocked.

Collectors cards, Arachnid style.

Collectors cards, Arachnid style.

Heating, cooling, and trying to drown Arctic pseudoscorpions

The Beringian Arctic pseudoscorpion is a charming Arachnid, living under rocks near sub-arctic rivers and streams, in primarily unglaciated parts of the Yukon. It has captured my fascinating for years, and the story of its natural history is starting to unfold. However, some fundamentals about the biology of Wyochernes asiaticus remain unknown: as the most northern pseudoscorpion in North America, how does it survive in such cold climates? How is it adapted to frequent flooding that occurs in its primary habitat, next to streams and rivers?

The Arctic pseudoscorpion, Wyochernes asiaticus

The Arctic pseudoscorpion, Wyochernes asiaticus

Science is a collaborative process, and I teamed up with two thermal biologists to start to answer some of these physiological questions. PhD student Susan Anthony and Prof. Brent Sinclair*, both from Western University in Ontario, came to the Yukon with us last summer, and together we collected pseudoscorpions at Sheep Creek, just north of the Arctic Circle. Part of Susan’s PhD research is about the thermal biology of Arachnids, so Susan and Brent wanted to see what we could learn about Arctic pseudoscorpions. They brought the wee arachnids back to Ontario, and Susan ran a series of experiments, resulting in a recent publication (in Polar Biology).

Susan Anthony and Brent Sinclair, both from Western University.

Susan Anthony and Brent Sinclair, both from Western University.

The experiments may sound a little cruel, but they are the standard approach when studying some of the cold tolerance, thermal biology and physiology of arthropods. Susan heated up and cooled down the critters, and discovered that they can survive up to about 38 degrees Celsius, and down to about -7 degrees Celsius. The upper threshold is relatively low compared to other arthropods, which makes sense since W. asiaticus lives at high latitudes. Because the specimens didn’t survive freezing, we know it’s ‘freeze avoidant’ rather than ‘freeze tolerant’. This is aligns with what we know from many other northern (or southern! i.e, in the Antarctic) arthropods. Presumably the pseudoscorpions adapt to the north by being able to supercool, or perhaps by cryoprotective dehydration,. However, its lower threshold isn’t that low, given the extreme cold winter temperatures in the Yukon. But since our collections were in the mid-summer, this might mean it’s not yet started to adapt, physiologically, for the colder winter conditions.

The next experiments involved immersing the pseudoscorpions in water and seeing how long they survive. This was done because we were very curious to know how these tiny animals might live in habitats that flood frequently. Amazingly, 50 percent of the arachnids survived under water for up to 17 days (!), and after testing with de-oxygenated water, Susan had a similar result: they certainly weren’t relying on oxygen in the water for breathing. Susan did notice, however, that they appeared to have a silvery bubble or ‘film’ around their bodies when immersed so we assume they used this air bubble for breathing during the immersion period, something known from other arachnids.

Sheep Creek, Yukon - a habitat that frequently floods: now we know how the tiny Arachnids survive the flooding!

Sheep Creek, Yukon – a habitat that frequently floods: now we know how the tiny Arachnids survive the flooding!

Putting this in the context of the pseudoscorpion’s habitat in the Yukon: it seems that the sub-arctic rivers in the Yukon typically flood for periods up to 10 days, in the spring. Our little arachnid likely just hunkers down in their habitats under rocks, breathing from air trapped around its body, waiting for floodwaters to recede.

I’m very excited about this paper, in part because of what we have learned that links the ecology of the species to its physiology. I’m also excited because this work represents a major advancement in the fundamental knowledge about Arachnids. Our work is the first to uncover any basic biology related to the physiological adaptations of pseudoscorpions to cold/heat and to immersion tolerance.

This is kind of stunning: the Pseudoscorpiones are an entire Order of Arachnids, yet nobody has ever worked to figure out how they adapt, physiologically, to extreme environmental conditions. AN ENTIRE ORDER! And it’s 2015! An analogy would be figuring out that some butterflies (Order Lepidoptera) bask in the sun, to thermoregulate. Or, like figuring out how ducks (Order: Anseriformes) don’t freeze their feet when standing on ice. These are ‘textbook’ examples of thermal biology and physiology – such facts could be considered common knowledge. Yet looking to the Arachnids, the story of the thermal biology of pseudoscorpions has only just begun. One paper at a time, we will continue to make progress.

The Arctic pseudoscorpion: it has stories to tell. Photo by C. Ernst, reproduced here with permission.

The Arctic pseudoscorpion: it has stories to tell. Photo by C. Ernst, reproduced here with permission.

As Tschinkel & Wilson state, every species has an epic tale to tell. Even tiny arachnids that live under rocks above the Arctic circle are proving interesting for many scientific disciplines: each chapter of its story is starting to unfold, and I’m quite sure there are a lot of very interesting chapters still to come.

Reference:

Anthony, S.E., C.M. Buddle and B.J. Sinclair. 2015. Thermal biology and immersion tolerance of the Beringian pseudoscorpion Wyochernes asiaticus. Polar Biology.

——

*A sincere thanks to Brent and Susan for including me on this paper, and for being willing to come to the Yukon with our team, to do collaborative research. I’ve learned a great deal in the process, and am delighted that partnerships between ecologists and physiologists can work out so well.

Questions and answers about spiders

Spiders, spiders, everywhere. I get asked a LOT of questions about spiders – from students, friends, neighbors, over twitter, and from journalists. I recently spent some time talking to a journalist in my hometown about spiders in Quebec*, and thought to share the details here! Here’s a copy of some of the Q&A with the journalist:

A beautiful dock spider (photo by Sean McCann)

A beautiful dock spider (photo by Sean McCann)

Q1) Why your obvious fascination with spiders?

Spiders are fascinating because they have remarkable biology and life history, and are certainly as beautiful as all other animals. They are the top predators in their own world, feeding on insects that may cause economic damage to our crops, or catching mosquitoes that seek us out for a blood meal. They build stunning webs, have remarkable diversity of body types and the live almost everywhere on the planet (all terrestrial parts, except the Antarctic). As babies the ‘balloon’ up into the air, and are among the best dispersers in the world – better than many flying insects. They are among the most common animals in ecosystems – we have recorded, for example, that wolf spiders occur in densities of over 1 spider per square m in parts of the Arctic tundra. What’s not to love?

Q2) How long have you been interested in them and why do you think they have a bad rap with so many people ?

I became interested in spiders when I was doing my undergraduate degree at the University of Guelph. A botany Professor there was working on the old cedar trees growing off the cliff faces of the Niagara escarpment, and during one summer he hired me to help with that work. While hanging off cliff faces, I couldn’t help but notice SO MANY SPIDERS and this piqued my curiosity, Professor Larson then allowed me to do a research project in the lab, and I did that project on spiders. Like to many things … a little knowledge is a dangerous thing. As I learned more, I became more and more fascinated by Arachnids, and continued on to do another undergraduate research project on spiders, and it just continued and continued until this day. I have been working with spiders now for over 20 years of my life.

Arachnophobia is real and serious for many people, but in many cases, people are not necessary arachnophobic, but rather have a general (unfounded) loathing for spiders and I believe this is largely because they have not explored their incredible biology and natural history. With education, I find people can shift from fear to curiosity and amazement. There have been studies done that illustrate that the ways that spiders move, and their extra legs, may contribute to a general fear of spiders – in other words, they can surprise us and are so “Leggy” that it causes a startle reaction and this perhaps leads to fear. This is very common in our society, and this feeds a cycle of fear, as our children learn fears from us. There may be some genetic basis to being afraid of spiders, also, and this probably relates to the fact that some spiders are indeed venomous to humans. In this part of the world, however, there are very few spiders of medical importance, and spider bites are exceedingly rare. Although everyone has a story about a spider bite, most of these are not verified, and other more likely causes should be investigated. Misdiagnosis is common in the medical field, also.

Q3) Why are they beneficial in the garden? And, even in moderation I assume, in the home ?

Spiders are beneficial because they eat many insects that themselves can be harmful to our gardens. In our homes they also feed on other insects that live in our homes. Without spiders, we would certainly have more other critters in our house and garden.

A cellar spider, with prey (c) A. Bradford

A cellar spider, with prey (c) A. Bradford

Q4) How many types of spiders do you think we have in this region and what would you estimate their total population to be?

There are over 40,000 different species of spiders in the world, over 3,000 species known in Canada, and over 600 species known from Quebec. That is a LOT of different kinds of spiders! There are certainly more species of spiders in the world than there are mammals or birds. I estimate an average yard in any small town in southern parts of Canada harbour easily 20-30 different species, and our local forests certainly can have over 100 different species.

It’s difficult to estimate population (i.e., how many of each kind of spider), but it’s fair to say that the old saying that you are always within three feet of spider is likely quite accurate, at least when you are in natural environments. The sheer biomass and density of spiders in some parts of the world is truly astounding.

Q5) What are some of the most common kinds of spiders?  What do they do during the winter?

Common spiders in our homes include things like the “Zebra jumper” Salticus scenicus it’s the little black and white jumping spider that is common in our window sills or on the walls of our houses, especially on warm summer days. Many of us have the Cellar spiders Pholcus phalangioides in our houses (they have long, gangly legs, but are not to be confused with “Daddy long legs – aka Harvestmenpersons – they are cousins to spiders, but not actually spiders!). In our gardens in the late summer, we see many individuals of the black-and yellow garden spider Argiope aurantia – it’s very large, with black and yellow striping on its abdomen, stringing up its huge webs in our gardens. Another very common orb-weaving spider, that also matures in the late summer, is Neoscona crucifera. We often see funnel-web or grass spiders (Agelenopsis) on dewy mornings: they can build their sheet-webs (with a funnel retreat at one end) on shrubs or on our lawns, in very high densities – obvious with a heavy layer of dew. We also find Canada’s largest spider in southern Quebec – an impressive animal!

The cute Zebra jumper (By Alex Wild)

The cute and common Zebra jumper (By Alex Wild)

Spiders do various things in the winter – in some cases the egg cases overwinter, and in other cases the spiders overwinter. Most spiders are “freeze avoidant”, meaning that they cannot freeze without dying, so they often adapt by ‘supercooling’ which essentially means they produce antifreeze in their bodies so they will survive below freezing temperatures. Spiders generally find places to hide in the winter, whether it’s in leaf-litter, under rocks, or finding a way into our warm basements.

Q6) Do you have a personal favourite spider?  If so, why, and what is it called?

I really like the ant-mimicking jumping spiders such as Peckhamia pictata  – it occurs in Quebec, and is a marvellous mimic of ants – most people don’t notice it because it fools us by its shape and behaviour – and so very easy to mistake as an ant instead of a spider. There are, in the world, about 300 different species of jumping spiders that mimic ants – a behaviour that is more common in the tropics, but also happens with some species here in the north.

Q7) How long have spiders been around on Earth and how long do spiders, on average, live?

Spiders have been around for perhaps 400 million years, which is a very, very long time. They have been on this planet far longer than us!

In this part of the world, spiders typically live one year, although some larger species may take more than one year to reach adulthood. In captivity spiders can live a very long time – I have a Tarantula named Harriet, in my lab at McGill, and she is approaching 20 years old.

© C.M. Buddle (2015)

*indeed, this Q &A was Quebec-focused, so may not be generalizable to all parts of the world!