A Cool New Backyard Visitor!

One of the joys about moving, and there are but few, is discovering the new critters inhabiting your property! My wife found this Spinybacked Orbweaver hard at work in our yard yesterday.

Spiders, Contributing to Frog Declines

Colbert Picks Spider Number...

... You'll have to watch to find out!




Hat Tip to Rod Page. Aptostichus stephencolberti is described in the latest issue of Systematic Biology(DOI:10.1080/10635150802302443).

1705 Insect Monograph

Tarantula & Weaver Ants in Guava Tree

Maria Sybilla Merian's Metamorphosibus Insectorum Surinamensium is an exquisite collection of scientific drawings from an extremely talented artist and entomologist. Some of the watercolors of these plates are in a show "Amazing Rare Things", a collaboration between David Attenborough and the Queen's Gallery in London. For those of us not in England... they have a nice website with great images and commentary by David. The original watercolor of this plate was purchased by none other than King George III (albeit when he was the Prince of Wales).

Check out more plates, as well as the backstory on the volume and Merian at the brilliant site for bibliophiles - BibliOdyssey.

Audubon House Gallery also has a very nice collection of her watercolors available in the Merian Gallery

Help Artist Out With Deadly Spider Bite Treatment

Matt Woodson is a very talented comic-book style artist, hit by a very dangerous spider in an unfortunate circumstance. Help out a brotha! I will be contacting regarding my next tattoo. Via Boing Boing:

A poisonous spider bit artist Matthew Woodson, and the medical treatment is expensive. He's accepting commissions to offset the costs of the treatment, which is expected to last eight months. (Portfolio here)

On Monday of last week I was bitten by a yet unknown poisonous spider on my right knee. By Tuesday I was running a high fever and unable to walk. On Friday evening I collapsed and was rushed to the ER. After a series of x-rays and a whole lot of examination, I was informed that I had a rather large abscess and cellulitis due to the spider's bite. I was sent home early Saturday morning after having my knee surgically "drained", and in more pain than I have ever been in. After a doctor's appointment this Monday, another abscess was drained and I was informed that I would need to see a doctor weekly until the wound had healed, which could possibly take up to 8 months. Within these 8 months there will remain the very real threat of the infection spreading into the bone of my knee, as well as the possibility of blood poisoning.

Any possible commission you could have for me; gifts, wedding invitations, cards, wall art, tattoos, anything. I am interested in the job. I will also definitely consider larger personal commissions, considering the work involved. I would prefer to only be working in black and white, but don't be afraid to ask about color. I haven't exactly figured out how pricing will go yet, but obviously pricing will be negotiable and varying, but for small to medium sized drawings I was thinking between $100 - $500 through paypal.

See Woodson's post for more information: Kill Spiders, Buy Art.

Inverts 10: Verts 2

Thanks to Johann in a comment at a previous post who alluded me to another Tarantula vs. Snake video. This time it was a coral snake though, which are pretty frikkin deadly. Good job Mr. Tarantula!

The recap (winners are italicized):
Ants vs. (dead) lizard
Tarantula vs. Fer de Lance Snake
Mantis vs. Snake
Octopus vs. Fish
Jellies vs. Salmon
Man Sized Sea Scorpions vs. Armor Plate Fish
Octopus vs. Moray + half dozen fish
Centipede vs. Bat
Centipede vs. Mouse
Octopus vs. Shark

Inverts 8: Verts 2

We already showed the unworthiness of snakes in the last episode. Just to kick them when they're down, lets watch a snake can pwned by a Tarantula!

Hat tip to not exactly Ed Yong.

Archives of the previous fights:
Mantis vs. Snake
Octopus vs. Fish
Double feature: Man Sized Sea Scorpions vs. Armor Plate Fish and Jellies vs. Salmon
Octopus vs. Moray + half dozen fish
Centipede vs. Bat
Centipede vs. Mouse
Octopus vs. Shark

Cave Inverts Prefer Exotics

While the deep-sea may be the final frontier for marine biologists, caves are one of the least studied environments on land. Some caves can extend dozens of miles below the ground in sinuous networks, all but cut off from the grassy hills and tree-lined horizons above. Its not an easy environment to access and many explorers have perished attempting to map these subterranean labyrinths. Yet, recent investigations have found an astonishing community of invertebrates associated with caves, existing nowhere else. Many of these species are insects and spiders, adapted to the dark conditions, muggy conditions. Nearly every new cave expedition turns up species never before seen.

How do these animals exist down there? What is their source of food? It turns out that nestled in the Blue Mountains of Australia at the 350 million year old Jenolan Caves Karst Conservation Reserve, the base of the invertebrate community consists of decaying leaf litter. Eucalyptus trees, native to the area, historically contributed the most to the leaf litter pool. Over the years, introduced trees have naturalized around the cave opening. Sycamore from Europe was brought in to stabilize steep, rocky slopes and Radiata Pine from North America was provided for the timber industry. Hills and colleagues from the University of Technology Sydney compared leaf litter decomposition rates and invertebrate diversity between the 3 leaf litter pools in "twilight" areas (i.e. near cave openings) and "dark" areas deeper in the cave.

The introduced Sycamore leaves decomposed much faster than the radiata pine needles and native eucalyptus leaves. This suggests that Sycamore leaves release more carbon and nutrients into the cave ecosystem, potentially supporting a more abundant and diverse invertebrate community. Interestingly, there was no difference in leaf mass loss between twilight and dark leaf litter. Proximity to above-ground features like light, rain and wind appear not to affect leaf litter decomposition.

Before I discuss the trends for invertebrates there, I want you to sit back in your chair, take a deep breathe and relax. Close your eyes and envision a cave. Its dark, moist, there is only one opening. All that remains of it is a singularity of daylight. For hundreds or thousands of years this cave has been fed organic matter from the surrounding vegetation. Trees such as Eucalyptus abound in the limestone hills, shedding off their leaves which make their way by the cave opening eventually being blown in by a gust of wind. This occurs daily for millennia. Insects and arachnids feast on the leaves as well as the fungi and bacteria associated with the leaf matter. Over time one might suspect that the animals become adapted to the leaf litter type in some way.

Fast forward to the last 100 years and globalism has introduced new organisms to every corner of the planet at an unprecedented pace, including Sycamore and Radiata Pine to eastern Australia. Are the invertebrate communities more diverse and abundant on the native vegetation that is may have adapted to?

As you can see from the above figures, abundance and species richness are much greater for the introduced european Sycamore than either the pine or Eucalyptus, especially nearer the cave opening. The authors don't really nail the answer with their experiment, but narrow it down to attributes of Sycamore that favor colonization by invertebrates over Pine and Eucalyptus. For instance, Sycamore has a higher specific leaf area (SLA) than both Pine and Eucalyptus. A low SLA is associated with long-lived leaves containing many structural and defensive compounds. These trees invest heavily to guard against plant-eaters whereas the broad-leafed Sycamore does not invest against herbivory, so leaves break down quickly. This faster nutrient release may be part of the reason sycamore leaves have a more abundant and diverse community.

So what would happen if Sycamore were to completely supplant Eucalyptus? It is a higher nutrient leaf and releases carbon faster (i.e. breaks down faster), so it should be better for the spineless society down under, right? One problem is that Sycamore is a deciduous tree. This means nutrient pulses to the caves would occur on a seasonal basis. Since its leaves break down so quickly, this pulse would be short lived compared to the structurally-strengthened Pine and Eucalyptus, both of which keeps their leaves year-round. Being below-ground, caves are protected from the variability of the seasons and are relatively stable environments in terms of climate. The invertebrate community there needs a more constant or stable supply of leaf litter to be sustained. The authors propose

"The short-term influx of energy provided by sycamore litter could be detrimental to subterranean invertebrate diversity in the long term. We would expect to see invertebrate species predisposed to utilizing sycamore derived energy dominating subterranean invertebrate communities and perhaps out-competing other invertebrate species, thereby reducing invertebrate diversity."

Interesting food for thought: nutrient pulses reduce diversity over time. On the other hand, if the authors are talking about partial species replacement, I would also expect to see increase in diversity pooled over the whole year. If this is only a seasonal phenomenon, complete species replacement would be unlikely given that established invertebrates that can utilize multiple plant sources over the year will persist over the long-term. It would certainly be an idea worth funding, especially from the angle that caves may be sheltered from the immediate effects of climate change. A nice replicated mesocosm study within the caves and near the entrances. 'X' amount of replicates sampled throughout the year at various time points to gauge the effect of seasonal nutrient pulses. How about adding various mixtures of different quality leaves to test the hypothesis that maximum food quality results in highest species richness.
------------------------------------------------------------------------------------------------
HILLS, N., HOSE, G.C., CANTLAY, A.J., MURRAY, B.R. (2008). Cave invertebrate assemblages differ between native and exotic leaf litter. Austral Ecology, 33(3), 271-277. DOI: 10.1111/j.1442-9993.2007.01814.x

Rednecks Build Mechanical Spider Because They Can.

I think I must agree with the poster of this video on YouTube:

"I have no idea who these guys are, but they managed to build an 8-legged, gas-powered spider mech in their spare time. Screw NASA and DARPA - turn them over to rednecks plus Burt Rutan and we'll have a Mars colony and Robotech in 10 years."

Hat Tip to Seiberwing.

356 Fossil Animals Found in X-Rayed Amber

This is just an awesome find. From the European Synchotron Radiation Facility:

"Opaque amber accounts for up to 80% of the amber found in Cretaceous sites like those in Charentes. From the outside, it is impossible to tell whether something may be contained inside. Malvina Lak and her colleagues from the University of Rennes and Paul Tafforeau of the ESRF, together with the National Museum of Natural History of Paris, have applied a synchrotron X-ray imaging technique known as propagation phase contrast microradiography to the investigation of opaque amber. This technique permits light to reach the interior of this dark amber, which resembles a stone to the human eye. “Researchers have tried to study this kind of amber for many years with little or no success. This is the first time that we can actually discover and study the fossils contained within”, says Paul Tafforeau.

The scientists imaged 640 pieces of amber from the Charentes region in south-western France. They discovered 356 fossil animals, ranging from wasps and flies, to ants and even spiders and acarians. The team was able to identify the family for 53% of the inclusions.[...]"

"Examples of virtual 3D extraction of organisms embedded in opaque amber: a) Gastropod Ellobiidae; b) Myriapod Polyxenidae; c) Arachnid; d) Conifer branch (Glenrosa); e) Isopod crustacean Ligia; f) Insect hymenopteran Falciformicidae. Credits: M. Lak, P. Tafforeau, D. Néraudeau (ESRF Grenoble and UMR CNRS 6118 Rennes)."

Hat tip to Martin!

Work With an Invert! - Natural Sciences Curator in South Africa

Research position at Natal Museum, Pietermaritzburg, South Africa

CURATOR: NATURAL SCIENCES
RESPONSIBILITIES:
The Natal Museum researchers conduct research in various fields of natural sciences. The main responsibilities for this position are:
· Undertake original research (either independently or under the supervision of a chief curator), with emphasis on the unique resources housed in the Natal Museum: ideally molluscs, or other non-insect invertebrates such as myriapods, arachnids and earthworms.
· Register for higher postgraduate qualification where appropriate.
· Augment the collections through fieldwork where appropriate.
· Critically evaluate and interpret data, and prepare high quality manuscripts that meet the standards of the international scientific community.
· Formulate targeted research projects and submit applications to external funding bodies.
· Assist in efficient management and databasing of the collections, and provide guidance and scientific advice where necessary.
· Provide external and internal clients with authoritative information relating to collections and field of research expertise.
· Engage in collaborative research projects to enhance research capacity.

REQUIREMENTS: PhD degree in relevant field is preferable, ideally with publication record and curatorial experience. Applicants with an Honours or Masters Degree in relevant field may be considered if they intend to continue academic studies. Good existing knowledge of the research field and understanding the role of museum research are essential. Ability to generate funds, conduct research and communicate scientific results to academic community, general public and other interest groups. Excellent writing, presentation and communication skills. Valid drivers licence.

SALARY: Negotiable at salary level 8 of Public Service Employees.

The Natal Museum is an equal opportunity affirmative action employer, whose aim it is to promote representativity in all levels of occupational categories in the institution. Applications should be posted to: The Deputy Director: Natal Museum, 237 Jabu Ndlovu Street, Private Bag 9070, Pietermaritzburg, 3200.

No faxed applications will be accepted.
The Natal Museum reserves the right not to make an appointment.
Please send a covering letter stating the position you are applying for, a detailed resume with a list of references and certified copies of all qualifications.
Further enquiries regarding these positions can be directed to the Deputy Director.
Closing date for submission of all applications is 15 February 2008, at 12:00. Late applications will not be accepted. If you have not heard from us by the 20 March 2008, please consider your application to have been unsuccessful.

237 Jabu Ndlovu Street, Pietermaritzburg
For a never ending journey of discovery!

Assassin Bugs Use Corpses to Avoid Predators

Not only can your prey give your nourishment and a full belly, it can also be a shield to protect you from predators! A recent article by Jackson & Pollard in the Journal of Zoology described an interesting study in which the ant-snatching assassin bug (Acanthaspis petax) makes a "backpack" of its dead prey to avoid being seen by its predator, the deadly jumping spider (Salticidae)! Masking to avoid predation is not a novel development. There are decorator crabs who will take just about anything and put it on its back (including other live critters), sea urchins will don mussel shells and some weevils will even grow fungi, algae or moss on its back. What I think is cool about this system is the use of "corpse camouflaging". Not only can it save you from starvation, it can save your butt too!

"...they capture prey by grabbing it with their legs, piercing it with their syringelike mouthparts and using the ‘syringe’ to inject digestive enzymes and paralysing saliva. The bug then proceeds to suck up the digested ant tissues from inside the ant’s exoskeleton. Once finished, the assassin bug places what remains of the ant, an empty shell, on its back. The ant carcass adheres because of fine adhesive threads that the bug secretes from its abdomen."-Jackson & Pollard (2007)

Now thats recycling! I think we can learn something here. Perhaps we should recycle our food waste into new and life-saving innovations. Hmm... what can we do with all those leftover lemon and orange rinds?

Figure 1 (from Jackson & Pollard (2007)): Two juvenile Acanthaspis petax: one without (left) and one with (right) a mask constructed of ant carcasses.

Jackson & Pollard (2007) demonstrated that Acanthaspis with corpse backpacks were significantly picked off less by jumping spiders. They tested this using 3 different jumping spiders: Hyllus sp., Plexippus sp. and Thyene sp. Salticids are vision-guided predators so they would not be able to detect the assassin bug by smell per se. Spiders were presented either with naked, or unmasked, bugs or bugs masked with the putrid remains of their last meals (see figure above).

The result is that hits by all three species of spiders significantly increased when bugs were unmasked, meaning that the corpse camouflage is a successful deterrent to predators. To test whether the size of the mask affected attacks, the authors made lures that either exceeded or were shorter than the length of the naked bug. The result was the same in all scenarios: unmasked bugs were attacked an order of magnitude more than masked bugs. Hence, prey size is not a factor and the disparity between masked and unmasked bugs is due to the shield of dead ant bodies in and of itself. The lures also helped to control for confounding variables of using the live bugs (motion, behavior and other sensory cues), lending strength to their study.

But why a mask constructed of ant corpses? Ants are not necessarily the best prey for many species and are well respected across the animal kingdom. Typically ants are chemically defended or behaviorally defended (think of the swarming behavior of some species of ants), making them a difficult prey item. Additionally, there's not a lot of meat there so the effort put in might not balance with nutrition received. The authors hypothesize that their data suggest

"... that the salticid readily detects the masked bug as an object separate from the background, but it fails to identify it as potential prey.[...] As most salticids may be averse to preying on or coming close to ants (Nelson & Jackson, 2006), the fact that the bug’s mask is normally made of ants may be important when the bugs encounter salticids."-Jackson & Pollard (2007)

It would be interesting to see how this behavior evolved, what genes turn on this behavior. Once the gene(s) is/are found, how does that gene's phylogeny map over more conservative (i.e. less selected) genetic markers like mitochondrial DNA? A cross comparison with other decorating species would be very interesting in understanding the evolutionary history that gave rise to decorating behavior and how that behavior became instinct that is rooted in the taxon.
_____________________________________________________________________
Jackson RR, Pollard SD (2007) Bugs with backpacks deter vision-guided predation by jumping spiders. Journal of Zoology 273:358-363. doi:10.1111/j.1469-7998.2007.00335.x

Nelson, X.J. & Jackson, R.R. (2006). Vision-based innate aversion to ants and ant mimics. Behav. Ecol. 17, 676–681. doi:10.1093/beheco/ark017

Check One PhD Milestone Off!

Just like Pono the happy face spider, I am as happy as a spider to pass my comprehensive exam and move on with my life. Of course, I was passed with conditions. I have to write 2 reviews in areas my committee felt I needed more background in before my defense: species concepts and how to the community ecology of my system relates to that of other well-studied systems. I agree with them and felt my performance was definitely sub-par, but it what it is and they feel if I correct a few of my deficiencies than I will have no problem finishing my degree. Looks like I'll be helping pay John Wilkins living expenses. All in all they were very supportive and asked good questions that got me thinking about my research in new ways. It was a terrifying, but good, experience.

Glamorous Insects!

A friend sent me this webpage from Dark Roasted Blend on Glamorous Insects. Though they are not all insects, these unbelievable macro photos are better than National Geographic quality. I will steal one just to get you to go over there and see the rest! I really love the mantids.

Spineless Song of the Week - Video Blog: Thats Why the Spineless Are Atheist

This is my first attempt at a videoblog (vlog)! I wrote this song to explain to the public that even a creature with but a few coiled up ganglia knows there is no God, then why do we, with our large brains, insist on believing in superstition? Mark Twain, one of my literary heroes growing up, once wrote "Faith is believing what you know ain't so."

The video was shot at night in my backyard with a camping light and a candle using the iSight camera and microphone built into my Macbook. Yeah it was a bit chilly, which is why I am wearing a touk and jacket. Unfortunately, the combination of my children bedtimes, the thin walls and small space of our flat I am forced to take drastic measures to provide you with invertatainment. Thank "God" for Stoudt's American Pale Ale!

Thats Why the Spineless Are Atheist

Now listen here my good ole friends
And let me tell me you how this all ends
There ain’t no afterlife out there
Just a dead carcass with worms out the ears

For you it may come as a surprise
A great big scam, years of lies
But even more surprising to me
All we had to do was listen you see

It may have started fore the Precambrian
A little spark in earth’s great ocean
With a little time you’ll plainly see
Differential reproduction is the key

The critters have known since the end of time
Death and decay is all you’ll find
An endless cycle land, air and sea
But that don’t make some folk happy

Our spineless buddies have been trying to scream
There ain’t no God, its all dream
But we shunned them good and spit on their face
Now the jokes on us to our disgrace

If you ever sit and listen at the beach
You might just hear the crabs start preach
We’ve been changing for millions of years
Our diversity is high so listen here

If I were such an intelligent design
Why can’t I walk forward in a straight line
And perhaps if you take a close look you’ll see
Some crustaceans have asymmetry

If you ever walk through a tall forest
You might here spiders sing out in chorus
We’ve had millions of years to adapt
To cover this here entire map!

If I were but a special creation
Why should I die when I’m matin’
And if in our form there was no match
Why do some of us look like ants

Invertebrates as you can plainly see
Have tried to tell us for centuries
There can’t be no god you creationist
That’s why the spineless are atheist

LOLspider: Creationist WTF for the Week

I'm getting tired of overly-anthropomorphic creationists severely abusing the science of Invertebrate Zoology. I take extreme offense to this, especially some of the bogus claims I've recently discovered from the Yahya Cult. I don't think the work is new, the bottom of the page says copyright 2004. I'm not sure if it is the copyright of the online article or the last time the webpage was updated (in line with my stance on creationism, I prefer not to be "linked" to their sites, but a simple search for "evidences of creation" will get you there). I found about the abuses of the backboneless when I did a search on a keyword statcounter told me someone used to find my blog ("spider ant chacteristics"). To my utter shock, this blog came in below the EoC website! Uhn-buh-leev-uh-bull.

Its not that I think I am an authoritative subject on everything invertebrate, but I do have a background in the field and try to break down studies I personally think are interesting. I am assuming that the person was looking for quality information on jumping spiders that mimic ants. I will also assume that the unwary user clicked the first link, being rated the closest match by Google. What is absolutely mind-blowing is the amount of misinformation, outright lies and misconstrued creationist lead-ins spread in an article titled "The Miracle in the Spider". There's another fab article titled "The Miracle in the Ant" that I won't discuss here but all these points are relevant to that article as well.

I don't even know where to start. Right from the get-go they have no idea what they are talking about.

"The spider can use this amazing technique thanks to the power of hydraulic pressure in its eight legs."

Um... really? They are compressing fluid in their 8 legs to build up momemtum to make their jump? Well, all arthropods have fluid filled legs since they have an open or semi-open circulatory system, but they also have a little tissue type called muscle. Without muscle they would not move. period. But they do have a hydraulic component that is driven by muscles, probably from contraction of the prosoma (Schultz 1991).

"The ability of the jumping spider's eyes to see independently of the others enables bodies to be perceived more quickly. This capacity, proof of God's great knowledge, makes the jumping spider a master hunter."

Granted jumping spiders do have awesome eyes, but why wasn't God's great knowledge wasn't bestowed such ability on his most special of creations! I would love to see different things out all 8 of my eyes. Hmm... maybe its because of evolutionary constraints? My ancestor has 2 forward-facing stereovision eyes, sigh, we can't all be the lucky ones I suppose.

With regards to jumping spiders that mimic ants:

"These are a few of the characteristics which the spider needs to survive. Should one of them be lacking, the jumping spider would soon die. In this case it is impossible to say that the spider came by its characteristics by coincidence. The spider came into possession of all of them at the same time. God has created every living thing in a perfect form, together with every characteristic it will need."

Sure, every organism has a set of characteristics they need to survive, not a news flash there. For completeness sake, the necessary characteristics they highlight were having false eyespots to mimic ants eyes, carrying its front 2 legs high to mimic antennae, and copying the ant's walk and body position. They forget to mention a whole slew of other characteristics that are probably more important (if your thought process was evolutionary), but I'll work within these constraints. In fact, we see that because all ant-mimic spiders (the Myrmarachne genus) don't exactly look like one another or even share the exact same characteristics to survive, it did not come into all the necessary characteristics to survive simultaneously. If God created every living thing in perfect form, then why didn't God just make the spider an ant? In fact this spider evolved to mimic an ant through several millions of years by differential reproductive success of individuals most able to pass off as ants.

"In the case of Myrmarachne, an intermediate phenotype occurs during their development. Being transformational mimics, Myrmarachne can resemble a different ant species at each instar, but in some cases certain instars do not particularly resemble any ant species" - Ceccarelli & Crozier 2007

So even instars of the same species, hell same individuals, are polymorphic (more than one form) for the type of ant they mimic (or not). Ceccarelli & Crozier 2007 also studied whether the spider and ant co-evolved. An interesting result they found was there were was multiple host switching, even model switching evident in their phylogenies.

Figure 3 from Ceccarelli & Crozier 2007, ant species are on the left while the spider ant-mimic Myrmarachne is on the right.

There is some fluffy, bunny-hugging crap about spider's maternal instincts at the end. The article equates this with love and bitches in blind obedience to stupidity that equates the garbled mesh of ganglia which make up the arachnid brain to mammalian

Of course it is not possible to explain the concepts of love, compassion and the desire to protect in terms of any "blind" system. Because it is God who inspires all behaviour in animals, which lack consciousness and intelligence. It is not possible for any animal, of its own accord, to demonstrate sacrifice, to prepare plans, or indeed to do anything else. It is God who controls everything.

Blah blah blah yakkity yakkity yak.So does God control me to not believe in him and [some of] his followers to be dumbasses and violent, manipulative egoistic jerkoffs??
________________________________________________________________
Ceccarelli, F. S., Crozier, R. H. (2007) Dynamics of the evolution of Batesian mimicry: molecular phylogenetic analysis of ant-mimicking Myrmarachne (Araneae: Salticidae) species and their ant models. Journal of Evolutionary Biology, 20, 286-295.

Shultz, J. W. (1991) Evolution of locomotion in arachnida: The hydraulic pressure pump of the giant whipscorpion, Mastigoproctus Giganteus (Uropygi). Journal of Morphology, 210, 13-31.

Ant? Spider? You Decide!

During the course of my blogging here, I have become somewhat of a fan of spiders. My previous posts on spiders have focused on their unusual characteristics, such as doing the booty drop, showing off a little bling bling to catch the ladies eye, cutting off a leg to escape predators, and checking their web stats. I have developed an appreciation of spider diversity and behavior through reading papers that have caught my attention for this blog.

One of the reasons I absolutely adore the theory of evolution is that its predictive power can be so wonderful. The results of selection so wondrous in and of themselves. I am familiar with many aspects of symbiosis, having co-taught a class on the subject with my advisor (I covered mammalian herbivore digestion, termites, wood-eating bivalves, and bioluminescence) and working on the ecology of animals with chemoautotrophic bacterial endosymbionts for my dissertation research. I have seen alot of strange and unusual adaptations, but they just keep getting stranger and stranger the more I delve into the fantastic world of evolution and behavior. With this I now bring you the word of the week:

MyrmecomorphicIts a fantastic word brought to my attention by a recent paper published in the Journal of Natural History by Nelson & Jackson. What does this word mean? The root words "myrm", "eco", and "morphic" refer to ant, home(Aydin suggests eco may derive from echo meaning repeating, which makes more sense than deriving from oiko meaning home) and form respectively. Hence this refers to species that are an "ant-repeating form".As Christopher from the Catalogue mentions in the comments below, the most plausible definition is from the roots myrmeco- (derived from myrmex, "ant") and morphic ("form"), meaning ant-form or ant-like.


Top photo by Sean Hoyland and bottom photo courtesy Sandilya Theuerkauf, Wynaad, 2006, both from Wikipedia Commons.
This is a form of Batesian mimicry, which is between 2 different species that look very similar. The caveat is that one species is usually toxic, spiny or otherwise not very pleasant to eat, while the mimic is typically a fraud in the arena of danger. In the two photos above did you spot the real ant? If you count the legs its easy to tell. The individual in the top photo has 8 legs whereas the bottom photo is the Weaver Ant, Oecophylla smaragdina, the queen nonetheless. The mimic is Myrmarachne plataleoides (female shown in photo, males have gigantic mandibles, about 33% of their body length).

The spider genus Myrmarachne (Salticidae - the jumping spiders) is characterized by these fraudulent mimics with nearly 200 species of ant wannabes.

Ants are dangerous and unpalatable prey-size organisms and a variety of would-be predators of salticids, including other salticids and mantises, avoid making predatory attacks on, or coming close to, ants. Experimental studies have also shown that salticids and mantises that are averse to attacking ants are averse to attacking Myrmarachne"-Nelson & Jackson 2007

Top: Oecophylla smaragdina, Bottom: ant wannabe Myrmarachne plataleoides (female). Photos copyright Chih Fah Shin
As I've shown with other jumping spider posts (see links in first paragraph) they have quite complex mating behavior. Nelson & Jackson describe in detail the mating behavior of Myrmarachne assimilisand M. bakeri. Its quite the romance novel. Visualize a hot steamy jungle next to a white sand beach, a gentle breeze, seagulls laughing in the distance...

He's alone, walking through the brush and then he sees her. The morning dew glistening off her abdomen. Her four eyes catching the sunrise to the east. He arches his palp and twitches his abdomen, standing erect. She faces him, waves her palps in their air as he watches with anticipation. She turns away, he follows, she turns around, he waits. Her cephalothorax lowers, he dances in response, she lunges past him, yet is blocked by his desire. Eight eyes are staring. She tries to leave, but his approach beckons her. His legs erect, they brush up against her legs. She wants to run away, escape from these feelings, yet can't seem to pull away. The power of lust overcomes all her senses. She shifts her abdomen closer, he gently places his chelicerae upon her abdomen. Softly, calmly, he applies each palp once, then its over.

"When the male disengaged his applied palp, he moved over the female (her abdomen no longer raised or rotated), tapped and stroked and then, once positioned again beside the female, the male scraped his palp across her now flexed-up and rotated abdomen and resumed copulation. Before next palp application, while centered over the female, the male sometimes stepped backwards and forwards, stroking and tapping intermittently."-Nelson & Jackson 2007

Spider Double Whammy! Jumping Spiders Prefer Vegetated Corridors and Charity for Disabled Wolf Spiders

Spiders are just plain cool. In the recent issue of the Canadian Journal of Zoology, there were two interesting articles on spiders. The photo to the left is of the first paper's study victimsubject, Phidippus princeps (Photo: Bruce Marlin of Cirrus Images)

Jumping Spiders Prefer Vegetated Corridors

Baker 2007 conducted experiments with jumping spiders, Phidippus princeps (Salticidae), in which he manipulated corridors connecting patches of an old growth field (clover and alfalfa). Patches were either all not connected, all connected, or partly connected by vegetated corridors (as opposed to bare corridors) (see schema below, Fig. 1 from Baker 2007).



Baker found that P. princeps always preferred vegetated corridors and was never found on bare strips.

"The results of this experiment show that corridors are important for the interpatch movement of female P. princeps: spiders moved almost exclusively to patches connected by vegetated strips. In the absence of vegetated strips, spiders rarely moved cross bare substrate to a new habitat even in overcrowded conditions."

This has pretty fundamental consequences for movement and dispersal ecology. The fact that these spiders will not move across a non-vegetated corridor, despite reaching carrying capacity (Baker reports using densities 2-3 times that in nature), underlies the importance of connectivity between habitat patches. This is a ripe area of conservation research, which has mostly been done on large mammals like mountain lions, bears and other endangered verts (can we say LAME!). Invertebrates, typically being much smaller, are more subject to small changes and micro-habitat conditions. This study shows how important it is to maintain habitat corridors for the little guys.

"If an animal, as in the case of P. princeps, does not respond to density pressures when habitat patches are surrounded by unfavorable habitat, the persistence of fragmented populations may be severely compromised."

The fact of the matter is that critters won't risk it out in the open. They need cover to help ensure their survival when moving around. This is a nice arguement for conserving or creating corridors between habitat patches. The next step I think is to link similar principles to biodiversity and ecosystem functioning. Given the same initial starting compositions, do communities differ when habitat patches are linked versus unlinked, or various degrees between?

Charity for Disabled Wolf Spiders

Photo of a male Schizocosa ocreata from the Uetz lab website.
Wrinn & Uetz 2007 studied how leg loss and regeneration affected the condition, growth and development time in the wolf spider, Schizocosa ocreata (Lycosidae). Spiders are able automatize legs as a defense strategy, but it isn't clear what the trade-off is. For instance, if a spider amputates its leg and undergoes regeneration, does that impact future reproduction, make it more susceptible to predation later on, make it less mobile, less of a competitor, or make it harder to find food? Wrinn & Uetz examined the frequency of autonomy in the field and its relationship to size, mass and condition (residuals of the mass to cephalothorax regression, I'll post later about the efficacy of condition indices-something I use in my own research). They also did a laboratory study to test the hypothesis that leg regeneration impairs foraging, decreases growth and/or affects development time.

The field data they collected indicate that reduced foraging ability is associated with leg loss, evidenced by decreases in mass, size and condition. The laboratory experiments also suggest additional trade-offs. Though not significant, spiders regenerating legs took an average of 3.7 days longer to molt. One interesting observation was that

"Although spiders appear to show costs of regeneration, the differences in molt interval, size, and mass between intact and regenerating spiders were only true for the first molt after autonomy. During the second molt after autonomy, regenerating spiders were able to compensate for previous costs by either shortening their molt interval or increasing their growth."

It appears that these spiders are pretty flexible and bounce back to minimize costs of loss and regeneration to only one molt. Another trade-off was between development time and mass. Regeneration resulted in either longer time to molt or lower mass, but not both.

Jumping Spiders, aka Nature Pimps, Officially Named Sexiest Invertebrate of the Animal Kingdom

Not only do jumping spiders "drop it like its hot" to impress the hotties on the dance floor. Asian jumping spiders, not to be outdone by counterparts elsewhere in the world, flash a little bling bling to catch the ladies' eye. Taylor & McGraw report in the latest Current biology, that three-layered "scale sandwiches" of chitin and air produce a brilliant iridescent display that simply irresistible (photo to left, from Taylor & McGraw).

Only the scales of males reflect UV-light which the females can see, though humans being so intelligently designed cannot. When viewing a mirror image of themselves,

"males displayed aggressively to their mirror image, as we would expect one to behave towards a rival male; however, when UV light was filtered out, the males behaved differently, often courting themselves."-Taylor & McGraw 2007

They are so sexy even they can't keep their chelipeds off themselves!

"Females also seem to be paying attention to UV coloration in males; in experiments where UV light was filtered out, females ignored male courtship displays."-Taylor & McGraw 2007

Chica-chica bomp bomp oh yeah. Bang a gong and get it on.

Apparently, some really nerdy humans studied their scales and found that

"...each scale is composed of a sandwich structure with two outer corrugated chitin plates surrounding a thin layer of air (Figure 1C). This structure functions as a multilayer reflector, whereby the alternating layers of chitin, with a high refractive index, and air, with a low refractive index, organized at just the right periodicity with respect to the wavelength of light reflected, result in constructive interference, as light reflected off each interface emerges in phase"-Taylor & McGraw 2007

yadda yadda yadda. Whatever. This is just nerdspeak for male jumping spiders are the sexiest invertebrate in the Kingdom. Jumping spiders are so hot, just looking at the image above makes my retina sizzle.

Jumping Spider's Do the Booty Drop

Just a quickie, no pun intended, to guide readers over to Zooillogix for an awesome video of a jumping spider mating dance. Make your volume is on, the sounds are unreal! Click here for some bootyliscious jumping spider foreplay.