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



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.


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…



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”


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:


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.


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!


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.



The Arachnophile: hunting the wolf


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.



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.