A Master of Disguise (A Guest Post)

By Jake Klemm

Cephalopods are among the most intelligent of marine life. Their highly advanced nervous systems allow them to exhibit a complex array of behaviors (for example, camouflage). Within this array is a rather unique behavior observed in the cuttlefish Sepia pharaonis. These elegant beings are now known to… intensely flap their arms? These animals are truly graceful.

A lovely photo of S. pharaonis. Image by Silke Baron at Wikimedia Commons.

Researchers Kohei Okamoto, Haruhiko Yasumuro, Akira Mori, and Yuzuru Ikeda of the University of the Ryukyus in Okinawa, Japan observed this behavior on two separate occasions while studying S. pharaonis. The scientists had initially collected these cuttlefish with the intention of conducting other experiments but noticed this behavior while the cuttlefish were introduced to a large water-filled tank and while hunting prey. After noticing this wild arm-flapping behavior, the researchers turned their attention towards why the behavior was being displayed.

The researchers first observed this behavior in December of 2011. The cuttlefish were placed in a large, circular tank for conducting other experiments when a couple of them were observed to flap their arms. After the initial experiments were finished, a few of the cuttlefish were placed in the same sized tank and observations were recorded with a video camera over a period of five days. This behavior was revisited in 2013 for further observation. The cuttlefish they used were reared from eggs found in the same coastal waters of Okinawajima Island as the cuttlefish that were part of the 2011 experiments. Again, cuttlefish were placed in a large tank to observe the behavior with a video camera. The researchers counted each occurrence of the behavior and recorded the duration of each behavior. After observations were complete, the researchers performed experiments to observe the hunting ability of S. pharaonis. This arm-flapping behavior was observed unexpectedly while the cuttlefish hunted prey. The means of recording the behavior were the same as described above. In addition, the researchers recorded the number of prey caught between cuttlefish that did and did not display the behavior.

The researchers noticed variation in the frequency and duration of this behavior in the presence and absence of prey. When placed in a tank without prey, only a small number of cuttlefishes displayed this behavior. Of the cuttlefish that did flap their arms, the behavior lasted (on average) no longer than 37 seconds. However, the cuttlefish that were placed in a tank with prey, the behavior was displayed for at significantly longer period of time. In addition to that, more cuttlefish overall were seen flapping their arms in this second experiment. The cuttlefish that flapped their arms caught a significantly larger number of fish than the ones that did not flap their arms, despite being observed in the same tank and having access to the same number of prey animals. This observation led the researchers to believe that something about this unique behavior is helping the cuttlefish capture more prey.

A front view of a cuttlefish. Image by Stickpen at Wikimedia Commons.

The resemblance is uncanny! Image by Maximilian Paradiz at Wikimedia Commons.

What could this all mean? The researchers think that the cuttlefish may be mimicking another organism, specifically the hermit crab, to confuse the prey fish into thinking that they are another harmless animal. It is thought that the head of the cuttlefish resembles the shell of the hermit crab while the arms resemble the eyes and legs of the hermit crab. Posing as a harmless crab would allow the cuttlefish to get behind enemy lines and ultimately catch more prey. Further research will have to be done in lab as well as the field to see if this behavior is really that of mimicry. Other cephalopods are notorious for mimicking other animals, so it is not out of the realm of possibility. Studying this behavior would allow scientists to difurtveher into the evolutionary history of S. pharaonis. Until then, the graceful limb-flailing will remain an ever-tantalizing mystery.


References

Okamoto, K., Yasumuro, H., Mori, A., & Ikeda, Y., (2017). Unique arm-flapping behavior of the pharaoh cuttlefish, Sepia pharaonic: putative mimicry of a hermit crab. Journal of Ethology, 35(3), 307-311. DOI: 10.1007/s10164-017-0519-7

Nature's Halloween Costumes

A repost of an original article from October 23, 2013.

Image by Steve at Wikimedia Commons.

It seems like everyone is racking their brains to come up with a great Halloween costume. But we’re not the only ones to disguise ourselves as something we’re not. Many animals put on costumes just like we do. Take this gharial crocodile for example (do you see him?), covering himself in parts of his environment to hide.

Other animals, like this tawny frogmouth below, develop physical appearances that help them blend in with their surroundings. When threatened, these birds shut their eyes, erect their feathers and point their beak in such a way to match the color and texture of the tree bark.


Image by C Coverdale at Wikimedia Commons.

Rather than hide, some animals have a physical appearance to disguise themselves as other species that are often fierce, toxic or venomous. This type of mimicry is called Batesian mimicry, named after Henry Walter Bates, the English naturalist who studied butterflies in the Amazon and gave the first scientific description of animal mimicry. This plate from Bates’ 1862 paper, Contributions to an Insect Fauna of the Amazon Valley: Heliconiidae, illustrates Batesian mimicry between various toxic butterfly species (in the second and bottom rows) and their harmless mimics (in the top and third rows).


This plate from Bates’ 1862 paper, Contributions to an Insect Fauna of
the Amazon Valley: Heliconiidae is available on Wikipedia Commons.

The bluestriped fangblenny takes its costume another step further, by changing its shape, colors, and behavior to match the company. This fish changes its colors to match other innocuous fish species that are around so it can sneak up and bite unsuspecting larger fish that would otherwise bite them back! Learn more about them here.

The fish on the far left is a juvenile cleaner wrasse in the act of cleaning another fish. The two fish in
the middle and on the right are both bluestriped fangblennies, one in its cleaner wrasse-mimicking
coloration (middle) and the other not (right). Figure from the Cheney, 2013 article in Behavioral Ecology.

But the Master of Disguise title has got to go to the mimic octopus. This animal can change its color, shape and behavior to look and behave like a wide range of creatures, including an innocuous flounder, a poisonous lionfish, or even a dangerous sea snake! Check it out in action:

Caught in My Web: We Are Primates

Image by Luc Viatour at Wikimedia Commons

If the news cycle these days has you wondering about our own humanity, take a moment to reflect on our primate nature. For this edition of Caught in My Web, let's explore primate behavior in the news.

1. Elizabeth Preston at Discover writes about lemur "stink flirting" in High-Ranking Male Primates Keep Wafting Their Sex Stink at Females, Who Hate It.

2. Janelle Weaver discusses how primates grant favors for their own social benefit at Nature in Monkeys Go Out on a Limb to Show Gratitude.

3. Roxanne Khamsi at NewScientist reports that Envious Monkeys Can Spot a Fair Deal.

4. Writing for The Verge, Angela Chen explains how we discovered that bonobos prefer to befriend bullies in For Bonobos, Nice Guys Finish Last.

5. In Those Lying Apes, Dale Peterson of Psychology Today discusses chimpanzee deception.

Sound familiar?

Mind-Manipulating Slave-Making Ants!

A reposting of an article from October 10, 2012.

An entire colony enslaved by an alien species to care for their young. Slave rebellions quelled by mind manipulation. It sounds like science fiction, right? But it really happens!

Myrmoxenus ravouxi (called M. ravouxi for “short”) is a slave-making ant species in which the queen probably wears a chemical mask, matching the scent of a host species in order to invade their nest without detection. Once inside, she lays her eggs for the host species workers to care for. Armies of M. ravouxi workers then raid these host colonies to steel their brood to become future slave-laborers to serve the needs of the M. ravouxi colony.

A M. ravouxi queen throttling a host queen. Photo by Olivier Delattre.

Enslaved worker ants could rebel: They could destroy the parasite brood or at least not do a good job caring for them. But to selectively harm the parasite brood without harming their own nests’ brood, the host ants would have to be able to tell them apart. Ants learn the smell of their colony in their youth, so any ants born to an already-parasitized colony would likely not be able to tell apart parasite ants from their own species. But what about ants that were born to colonies before they were invaded?

Olivier Delattre, Nicolas Châline, Stéphane Chameron, Emmanuel Lecoutey, and Pierre Jaisson from the Laboratory of Experimental Ethology in France figured that compared to ant species that were never hosts to M. ravouxi colonies, ant species that were commonly hosts of M. ravouxi colonies would be better able to discriminate their own species’ brood from M. ravouxi brood. Host species may even be better at discriminating in general.

The researchers collected ant colonies from near Fontainebleau and Montpellier in France. They collected M. ravouxi colonies and colonies of a species that they commonly parasitize (but were not parasitized at the time): Temnothorax unifasciatus (called T. unifasciatus for “short”). The researchers also collected T. unifasciatus that were parasitized by M. ravouxi at the time. Additionally, they collected colonies of T. nylanderi and T. parvulus, two species that are never parasitized by M. ravouxi. (Sorry guys. All these species go by their scientific names. But really, that just makes them sound all the more mysterious, right?). The researchers took all their ant colonies back to the lab and housed them in specialized plastic boxes (i.e. scientific ant-farms).

On the day of the tests, the scientists removed a single pupa (kind of like an ant-toddler) from one nest and placed it into a different nest of the same species or back in its own nest. They did this for colonies of both non-host species and for colonies of host species T. unifasciatus that were not parasitized at the time. Then they counted how many times the workers bit the pupa (an aggressive behavior) or groomed the pupa (a caring behavior).

Workers from all three species bit the pupa that was not from their colony more than they bit their own colony’s pupa. But the T. unifasciatus (the host species) were even more aggressive to foreign pupa than the other species. And only the T. unifasciatus withheld grooming from the pupa that was not from their colony compared to the one that was from their colony. Although all three species seemed to be able to tell the difference between a pupa from their own nest versus one from another nest, only the species that is regularly enslaved by M. ravouxi decreased care to foreign young. So that is what these ants do when they are not enslaved. How do you think enslaved ants respond to their own species’ young compared to M. ravouxi young?

A 1975 cover of Galaxie/Bis, a French science
fiction magazine, by Philippe Legendre-Kvater.
Image from Wikimedia.

The researchers repeated the study using enslaved T. unifasciatus, placing either a pupa of their own species from a different nest or a M. ravouxi pupa in with their brood. Even though prior to M. ravouxi takeover the T. unifasciatus bit foreign pupa more than their own, after M. ravouxi takeover they didn’t bite foreign pupa of their own species or M. ravouxi pupa very much. Not only that, but they groomed the M. ravouxi pupa more than the pupa of their own species! Ah hah! Mind control!

This, my friends, is the kind of truth that science fiction is made from.

But how might this work? Ants born to an enslaved colony would be exposed to both their own odors and the M. ravouxi odors. Because ants learn the smell of their colony in the first few days after they emerge from their eggs, these enslaved ants would have a broader set of smells that they may perceive as being “within the family”. That would explain why the enslaved T. unifasciatus ants didn’t attack either the foreign-born T. unifasciatus or the M. ravouxi young, but it doesn’t explain why the enslaved ants provided more care to the M. ravouxi than they did to their own species. One possibility is that the M. ravouxi produce more or especially attractive odors to encourage the host workers to take care of them.

There is still more to learn about this system: How exactly may the M. ravouxi be hijacking the pheromonal systems of their host species? How are the host species protecting themselves from exploitation? I guess we’ll have to wait for the sequel.

Want to know more? Check this out:

Delattre, O., Chȃline, N., Chameron, S., Lecoutey, E., & Jaisson, P. (2012). Social parasite pressure affects brood discrimination of host species in Temnothorax ants Animal Behaviour, 84, 445-450 DOI: 10.1016/j.anbehav.2012.05.020

Fatal Attraction: Praying Mantises (A Guest Post)

By Britta Bibbo

We all know the character: an incredibly beautiful woman that seduces the rough-and-tumble action hero, only for him to later find himself chained up over a lava pit with sharks in it! …Or something like that. A “femme fatal” is the idea of a beautiful woman who leads men to their demise. None are more perfect for this role than the female praying mantis. Praying mantis females practice the art of deception through sexual cannibalism. It’s exactly how it sounds: the male is attracted to the female and tries to make some babies, but instead ends up being devoured. Sexual cannibalism hardly seems like a good strategy for keeping the mantis population up, but some argue it’s merely females taking advantage of every scrap of food they can find… even if it’s a loving male.

False garden mantis (Pseudomantis albofimbriata). Image by Donald Hobern from Wikimedia Commons.

When male mantises encounter a female in the wild they only have one thing on the brain, while a female may be more interested in self-preservation. If she hasn’t encountered food for a few days she will be VERY hungry and not all that interested in mating; in many species of mantises it is known that female mantises will eat males, even while having sex! So how do female mantises attract males?

For most insects, females are able to attract males with pheromones, chemicals released from an individual that affect other individuals of the same species. For instance, females can emit pheromones that will be telling of their age, reproductive status, and body condition. Males are able to detect pheromones from great distances and these pheromones play a role in allowing a male to determine how attractive a female could be. Before any sexy time can begin, females have to show that they are open to male advances. Showing a male you’ve never met before that you’re interested can be a difficult task- so females typically emit pheromones that are known as honest signals. These signals accurately convey female interest in mating, as well as her reproductive status, age, and body condition. Because the majority of females are being honest, males don’t have to think twice about their mate’s intentions. This is where female deception comes into play. If a female takes advantage of the lack of male wariness, she could end up with an easy meal. This deception by the females is what scientists know as the Femme Fatale hypothesis. This hypothesis explains that female mantises are naturally selected to deceive male mantises, and exploit them as food. This idea hasn’t had much backing evidence until Dr. Kate Barry of Macquarie University in Sydney, Australia sought to test this hypothesis with the false garden mantis (Pseudomantis albofimbriata).

After considering the test subjects and how the mantises communicate, Kate expected one of three possible outcomes:

1. There will be no pattern between female hunger and male attraction (if female false garden mantises are not femme fatales and false garden mantis pheromones do not communicate feeding-related information).

2. The well-fed females will attract the most males, while hungry females will attract the fewest males (if female false garden mantises are not femme fatales and females are always honest about their quality and willingness to mate).

3. The hungriest females will attract the most males, while well-fed females will still attract some males (if female false garden mantises are femme fatales and females are dishonest about their quality and willingness to mate when they are hungry).

To test her expectations, Kate gathered juvenile mantises that were close to their adult forms to have many male and female mantises that have no previous mating experience. Once the mantises were adults, females were given different feeding regimens to have a range of hunger. Categories included Good (well-fed), Medium (slightly less fed), Poor (hungry), and Very Poor (very, very hungry). Adult mantises were housed in a circular cage that separated each female individually around the edge, while the males were kept in the center.

Diagram of cage experiment was conducted in. Image by Britta Bibbo.

To allow the males to smell the female pheromones, researchers separated males by special walls that the males could not see through, but could still detect the pheromones given off by a female. The number of males on a female’s side of the cage was used to measure how attractive her pheromones were to the males.

The results of this study concluded that pheromones produced by the females that were very hungry were the most attractive to males. Through deception, the hungriest females are seen as sexier than well-fed, healthy females that are willing to mate! This result is surprising; normally females that are well-fed are seen as “sexier” because they have more nutrients available to them, making them more fertile. Hungry females have fewer nutrients available to them, making them less fertile, and therefore not as “sexy”. These hungry female mantises are advertising themselves as well-fed, fertile, and ready to rock when really, they’re not. Simply put, these results show that males are being catfished, and then consumed. Whether hungry females are actively trying to deceive males or if it’s just coincidental still needs to be looked into, but for now, be thankful for a partner who will see you as more than just a piece of meat!

Literature Cited:

Barry, K. (2014). Sexual deception in a cannibalistic mating system? Testing the Femme Fatale hypothesis Proceedings of the Royal Society B: Biological Sciences, 282 (1800), 20141428-20141428 DOI: 10.1098/rspb.2014.1428

Deception!

If you saw Friday’s video about the device that converts octopus gestures into English, hopefully you caught on that it was a pretty good (and hilarious) April Fool’s prank by Oregon Sea Grant. Although there is not a lot of evidence of animals deceiving one another for fun, deception is pretty common in the animal kingdom. Here are some examples:

1) Male nursery web spiders often court females with gifts of a tasty fly wrapped in silk to appease her while he mates with her. But some stingy sneaks will eat the fly themselves and wrap up the carcass, or worse yet, wrap up some random piece of junk. If she tries to snatch the gift from him, he hangs on and plays dead until she stops running, only to “come back to life” to mate with her then.

2) Cowbird moms lay their eggs in the nests of other species, relieving themselves of parental duties. But they stack the deck in favor of their own chicks: they often push eggs of the host bird out of the nest and color their own eggs to match that of the host. Their eggs hatch sooner and their chicks grow faster than their “siblings”, which the chicks promptly push out of the nest to their death.

This is a picture of begging chicks in a parasitized nest of a chalk-browed mockingbird, taken from a video. The chick with the smaller, redder gape at the top of the image is the cowbird. The other larger gapes belong to the mockingbird's own chicks. Photo by Ros Gloag.

3) Crocodiles have been found to place sticks on their snouts to lure in birds that are collecting nest material.

I’m just a floating log and sticks… Really. Photo by Dinets published in Ethology, Ecology & Evoluton 2013

4) A queen ant wears a chemical disguise to smell like another species, only to sneak into their nest and lay her eggs for this other host species to raise. The queen’s offspring then grow into an army that enslaves their adoptive colony, to serve their needs for life.

A 1975 cover of Galaxie/Bis, a French science fiction magazine,
 by Philippe Legendre-Kvater. Image from Wikimedia.

5) The mimic octopus pretends to be venomous fish and sea snakes so predators will avoid it.

The disguises of the mimic octopus: (a) shows a mimic octopus looking out of its burrow; (b) is a foraging mimic octopus with coloration to blend with the sand; (c) shows a mimic octopus as a sole fish and (d) is an actual sole fish; (e) shows a mimic octopus as a lion-fish and (f) is an actual lion-fish; and (g) shows a mimic octopus as a banded sea-snake and (h) is an actual banded sea-snake. Images from the Norman, 2001 article in Proc. R. Soc. Lond. B.

Octopus Thoughts Interpreted!

This is AMAZING! Scientists have developed a device that translates octopus gestures into English! Here is what this octopus was thinking:

Crocodilians Hunt With Tools!

A crocodile lures in birds with sticks that would make a nice nest.
Photo by Dinets published in Ethology, Ecology & Evoluton 2013.

What would happen to mankind if crocodiles and alligators were to develop enough intelligence that they could hunt with tools? Would we see the rise of new dominant species as in Rise of the Planet of the Apes?

Well, shudder in your boots, people, because we are already there!

This week at Accumulating Glitches I talk about the discovery of how at least two species of crocodilians use tools to lure in prey. Check it out here.

And to learn more, check this out:

Dinets, V., Brueggen, J.C.. and Brueggen, J.D. Crocodilians use tools for hunting, Ethology Ecology & Evolution, (2013). DOI: 10.1080/03949370.2013.858276.

Miss Behavior’s Picks of 2013



Image from freedigitalphotos.net.

2013 is quickly drawing to a close and we find ourselves in a time of reflection and reminiscences of the last twelve months. Science blogging continues to grow and our many talented and experienced science writers are finding themselves joined by a new cohort of young energetic writers bringing new perspectives. This is an exciting international community of passionate thinkers, debaters, and science communicators. These are my picks for The Top 5 Animal Physiology and Behavior Blog Posts of 2013 (not including The Scorpion and the Frog posts and in no particular order).

On the new blog, Viruses 101, Julia Paoli, a high school student and talented science writer discusses a scientific estimate of how many unknown viruses lurk within our fellow mammals in Mammals Harbor At Least 320,000 Undiscovered Viruses.

Natalie Wolchover at Quanta Magazine pondered the value of partial honesty among animals from a game theory perspective in Hunger Game: Is Honesty Between Animals Always the Best Policy?

We all carry communities of microbes within our bodies that have now been found to be involved in our health and behavior in ways we never previously imagined. In Inspiring Science, Sedeer el-Showk talks about research linking differences in our microbiomes to hormone levels and disease resistance in Sex, Hormones, and the Microbiome.

On EveryONE by PLOS Blogs, Alex Theg tells the story of a jumping spider species that uses multiple deceptive tactics. Read about the spiders that use visual mimicry to trick predator spiders and chemical mimicry to trick predator wasps in Ant-Mimicking Spider Relies on a “Double-Deception” Strategy to Fool Different Audiences.

Felicity Muth discusses animal homosexuality in her blog, Not Bad Science. Check out her article Homosexuality in Female Beetles, and What We Can Learn from It.

Merry Christmas and stay curious!

The Mimic Octopus: Master of Disguise

The disguises of the mimic octopus: (a) shows a mimic
octopus looking out of its burrow; (b) is a foraging mimic
octopus with coloration to blend with the sand; (c) shows
a mimic octopus as a sole fish and (d) is an actual
sole fish; (e) shows a mimic octopus as a lion-fish and
(f) is an actual lion-fish; and (g) shows a mimic octopus
as a banded sea-snake and (h) is an actual banded
sea-snake. Images from the Norman, 2001 article
 in Proc. R. Soc. Lond. B.

Different animal species have evolved a number of ways to hide in their environments. One of the most popular tactics is by camouflage, often by matching the background or by having patterns that break up the animal's outline (think: zebras and leopards). Others have evolved to resemble other species that are generally toxic or venomous, in a technique called mimicry. But a few amazing species have been recently discovered to have the ability to alter their mimicry to actively imitate a range of species, depending on their circumstances. The most remarkable of these is the mimic octopus, which shifts its shape and behavior to mimic a number of different species as fluidly as a real-life Mystique from the X-Men.

This week at Accumulating Glitches I talk about the remarkable acts of mimicry by one of our planet's most fascinating species, the mimic octopus. Check it out here.

And to learn more, check these out:

1. Norman, M.D., Finn, J., & Tregenza, T. (2001). Dynamic mimicry in an Indo-Malayan octopus Proc. R. Soc. Lond. B,, 268, 1755-1758 DOI: 10.1098/rspb.2001.1708

2. Hanlon, R.T., Conroy, L., & Forsythe, J.W. (2008). Mimicry and foraging behaviour of two tropical sand-flat octopus species off North Sulawesi, Indonesia Biological Journal of the Linnean Society, 93, 23-38 DOI: 10.1111/j.1095-8312.2007.00948.x

Nature’s Halloween Costumes

Image by Steve at Wikimedia Commons.

It seems like everyone is racking their brains to come up with a great Halloween costume. But we’re not the only ones to disguise ourselves as something we’re not. Many animals put on costumes just like we do. Take this gharial crocodile for example (do you see him?), covering himself in parts of his environment to hide.

Other animals, like this tawny frogmouth below, develop physical appearances that help them blend in with their surroundings. When threatened, these birds shut their eyes, erect their feathers and point their beak in such a way to match the color and texture of the tree bark.


Image by C Coverdale at Wikimedia Commons.

Rather than hide, some animals have a physical appearance to disguise themselves as other species that are often fierce, toxic or venomous. This type of mimicry is called Batesian mimicry, named after Henry Walter Bates, the English naturalist who studied butterflies in the Amazon and gave the first scientific description of animal mimicry. This plate from Bates’ 1862 paper, Contributions to an Insect Fauna of the Amazon Valley: Heliconiidae, illustrates Batesian mimicry between various toxic butterfly species (in the second and bottom rows) and their harmless mimics (in the top and third rows).


This plate from Bates’ 1862 paper, Contributions to an Insect Fauna of
the Amazon Valley: Heliconiidae is available on Wikipedia Commons.

The bluestriped fangblenny takes its costume another step further, by changing its shape, colors, and behavior to match the company. This fish changes its colors to match other innocuous fish species that are around so it can sneak up and bite unsuspecting larger fish that would otherwise bite them back! Learn more about them here.

The fish on the far left is a juvenile cleaner wrasse in the act of cleaning another fish. The two fish in
the middle and on the right are both bluestriped fangblennies, one in its cleaner wrasse-mimicking
coloration (middle) and the other not (right). Figure from the Cheney, 2013 article in Behavioral Ecology.

But the Master of Disguise title has got to go to the mimic octopus. This animal can change its color, shape and behavior to look and behave like a wide range of creatures, including an innocuous flounder, a poisonous lionfish, or even a dangerous sea snake! Check it out in action:

Hiding in Plain Sight



The fish on the far left is a juvenile cleaner wrasse in the act of cleaning another fish. The two fish in the middle and on the right are both bluestriped fangblennies, one in its cleaner wrasse-mimicking coloration (middle) and the other not (right). Figure from the Cheney, 2013 article in Behavioral Ecology.

Sometimes the best place to hide is right under everybody's nose. If you look like you are innocuous and you belong there, every so often you can get away with trouble.

The bluestriped fangblenny, a coral reef fish in Australia and Indonesia, takes this mimicry strategy to a whole new level. The bluestriped fangblenny doesn't simply look like another species, but it can change its look to resemble any of three different species, depending on who happens to be around! When surrounded by olive-colored damselfish, they take on an olive hue. When surrounded by yellow anthias, they turn orangey-yellow. But their most impressive costume is that of the black and blue striped juvenile cleaner wrasse. And when they are not around a species they mimic, they revert to a brown shade and hide.

This week at Accumulating Glitches I talk about how the bluestriped fangblenny uses mimicry of juvenile cleaner wrasse to sneak up on an bite their predators! Check it out here.

And to learn more, check these out:

1. Cheney, K.L. (2013). Cleaner fish coloration decreases predation risk in aggressive fangblenny mimics Behavioral Ecology, 24 (5), 1161-1165 DOI: 10.1093/beheco/art043

2. Cheney, K.L., Skogh, C., Hart, N.S., & Marshall, N.J. (2009). Mimicry, colour forms and spectral sensitivity of the bluestriped fangblenny, Plagiotremus rhinorhynchos Proceedings of the Royal Society B, 276, 1565-1573 DOI: 10.1098/rspb.2008.1819

The Real Catfish of Lake Tanganyika

Photo of Manti Te'o by Shotgun Spratling
and Neon Tommy at Wikimedia

Poor Manti Te’o may just be the most gullible schlub on the planet. For those of you that haven’t heard the story, the Notre Dame linebacker and runner-up for the 2012 Heisman Trophy led his team to the BCS National Championship Game, despite (or perhaps inspired by) the tremendous personal losses he has suffered this season. Last September, Te’o learned first of the death of his grandmother, and then within hours learned of the death of his girlfriend, Lennay Kekua. But after months of grieving and playing his heart out, Te’o began to receive phone calls from his “dead” girlfriend, telling him she missed him. Totally freaky, right? Notre Dame hired investigators to look into the undead girlfriend and they discovered that not only is Kekua not dead, she was never alive. The girl never existed. And what of Te’o’s relationship with her? According to Te’o, he never actually met her in person: Their entire long-term relationship took place online and over the phone, so he never realized that her entire persona was a fraud. He was completely and totally catfished.

He was what?

The top definition of catfish at Urban Dictionary reads:

“A catfish is someone who pretends to be someone they're not using Facebook or other social media to create false identities, particularly to pursue deceptive online romances.

Did you hear how Dave got totally catfished last month?! The fox he thought he was talking to turned out to be a pervy guy from San Diego!”

The term apparently originates with the 2010 documentary, Catfish, about a young man who falls in love with a woman on Facebook… who turns out to be someone else. Ew. But why the term catfish? A story in the movie explains that when cod are shipped from North America to Asia, their inactivity can result in mushy meat. Fishermen discovered that putting catfish in the cod tanks will keep the cod active and preserve meat quality. Like catfish for cod, the guy philosophizes, people that have deceptive identities keep idle people active. (The producers of the documentary now produce an MTV series by the same name about this online phenomenon).

But it’s not like real catfish can imitate others… Or do they?

Three poisionous Lake
Tanganyikan catfish. Figure from
Jeremy's 2010 Evolution paper.

A 2010 paper by Jeremy Wright at the University of Michigan at Ann Arbor documents the first known case of mimicry in catfish. There are several types of mimicry in the animal world. In this case, Jeremy was investigating functional Müllerian mimicry, a phenomenon in which two or more poisonous species mimic each other's predator-deterring warning signals (as opposed to Batesian mimicry, where a non-poisonous animal looks like a poisonous one). It may seem excessive to have both poison and warning coloration, but poison only helps after you’ve been bit. If your predators are smart enough to learn from experience, you can benefit from having more poisonous buddies around that look just like you so that if a predator bites just one of you it will then learn to avoid all of you. Sometimes it pays to look just like everyone else.

But just because you look like everyone else doesn’t mean that it is because you’re imitating others. I mean, maybe that’s just the way you look. So how do you know if a bunch of animals that look like one another are using functional Müllerian mimicry?

Jeremy studied a number of similarly-colored, poisonous and closely-related catfish species in the African Great Lake, Lake Tanganyika. All of these Tanganyikan catfish species (from the Synodontis genus) have dark spots on a yellowish background and dark fins with white borders. Could this be because of functional Müllerian mimicry?

Jeremy put a bunch of largemouth bass each into their own tank. Largemouth bass are predators that use their vision to find and eat most any fish that will fit in their mouths. But these bass were from Michigan, so they’d never had any experience with a poisionous, spotted Synodontis catfish. A clear barrier divided each tank in half and the bass was placed on one side of the divider, and a bite-sized fish was put on the other. The bite-sized fish was either a spotted and poisonous Synodontis multipunctata catfish, a spotted and poisonous Synodontis petricola catfish, or a not-spotted and not-poisonous minnow. He then counted how many times the bass struck the plastic divider in 5 minutes as a measure of how much that bass wanted to eat the bite-sized fish. After the 5 minutes were up, Jeremy removed the divider and watched to see if the bass ate the bite-sized fish. For each bass, he did this every day for 5 days, giving each bass the same species of bite-sized fish every day, so it could learn from its past experiences.

A naïve largemouth bass excited to eat a bitesized, but poisonous Synodontis petricola catfish.

A naïve largemouth bass gets to try to eat a bitesized, but poisonous Synodontis petricola catfish… and it doesn’t go so well for him.

A no-longer naïve largemouth bass gives his best death stare to a bitesized, but poisonous Synodontis petricola catfish. Videos provided by Jeremy Wright.

On the first day with the bite-sized fish, all the bass struck at the divider equally regardless of whether it was a spotted poisonous catfish or a minnow. But after their first bite, the bass given spotted poisonous catfish quickly lost their interest in them even though the bass given minnows continued to vigorously strike at them every day. When Jeremy later gave them a different species of bite-sized fish, those previously given a spotted poisonous catfish avoided both species of spotted poisonous catfish, but readily ate the minnows. So the bass had learned. Spotted catfish: bad! Minnows: yum! And the spotted catfish look was transferable between the two species… the hallmark of functional Müllerian mimicry. Further analysis of the venom revealed that these catfish species were all equally poisonous: Painful, but not deadly.

Online catfish like Lennay Kekua are usually like these real-life spotted poisonous catfish: painful, but not (usually) deadly. And they typically have facebook pages and twitter accounts full of sexy photos and superficial chatter. If we’re smart, we can learn to avoid them. Do you know if all your “friends” on social media sites are who they say they are?

Want to know more? Check this out:

Wright, J. (2011). CONSERVATIVE COEVOLUTION OF MÜLLERIAN MIMICRY IN A GROUP OF RIFT LAKE CATFISH Evolution, 65 (2), 395-407 DOI: 10.1111/j.1558-5646.2010.01149.x

Your Picks of 2012

This has been a wild first year for The Scorpion and the Frog. I have enjoyed sharing the world of animal physiology and behavior research with you. But even more, I have enjoyed hearing from you about your experiences, thoughts and perspectives.

I gathered data on page visits, comments, and social media attention for The Scorpion and the Frog posts and have determined your top five posts of the year. Here are Your Favorite The Scorpion and the Frog Posts of 2012 (in no particular order).

1. The “Love Hormone” Pageant pits six hormones against one another in a contest for the title of the “Love Hormone”. The "Love Hormone" of 2012 focuses on the big winner (as determined by reader votes), Dopamine!

2. Scientists put the philosophical question, “What Do Animals Think of Their Dead?” to the test. Their results may surprise you!

3. In Snakes Deceive to Get a Little Snuggle, we learn about boy snakes pretending to be sexy girl snakes, all in the hopes of a good cuddle.

4. Male nursery web spiders give silk-wrapped gifts to the girls that catch their eyes. But why waste a perfectly good present when a piece of junk in clever packaging will do? Sex, Lies and Spider Silk tells the story of these deceptive gift-givers.

5. Don’t Challenge a Fruit-Eating Bat to a Drinking Contest. Just don’t. Here’s why.

Thank you for your support and participation over the year. Next year should be full of new wacky animal stories. (And if you’d like to see my 2012 picks for my favorite animal physiology and behavior blog posts at other sites, click here).

Mind-Manipulating Slave-Making Ants!

An entire colony enslaved by an alien species to care for their young. Slave rebellions quelled by mind manipulation. It sounds like science fiction, right? But it really happens!

Myrmoxenus ravouxi (called M. ravouxi for “short”) is a slave-making ant species in which the queen probably wears a chemical mask, matching the scent of a host species in order to invade their nest without detection. Once inside, she lays her eggs for the host species workers to care for. Armies of M. ravouxi workers then raid these host colonies to steel their brood to become future slave-laborers to serve the needs of the M. ravouxi colony.

A M. ravouxi queen throttling a host queen. Photo by Olivier Delattre.

Enslaved worker ants could rebel: They could destroy the parasite brood or at least not do a good job caring for them. But to selectively harm the parasite brood without harming their own nests’ brood, the host ants would have to be able to tell them apart. Ants learn the smell of their colony in their youth, so any ants born to an already-parasitized colony would likely not be able to tell apart parasite ants from their own species. But what about ants that were born to colonies before they were invaded?

Olivier Delattre, Nicolas Châline, Stéphane Chameron, Emmanuel Lecoutey, and Pierre Jaisson from the Laboratory of Experimental Ethology in France figured that compared to ant species that were never hosts to M. ravouxi colonies, ant species that were commonly hosts of M. ravouxi colonies would be better able to discriminate their own species’ brood from M. ravouxi brood. Host species may even be better at discriminating in general.

The researchers collected ant colonies from near Fontainebleau and Montpellier in France. They collected M. ravouxi colonies and colonies of a species that they commonly parasitize (but were not parasitized at the time): Temnothorax unifasciatus (called T. unifasciatus for “short”). The researchers also collected T. unifasciatus that were parasitized by M. ravouxi at the time. Additionally, they collected colonies of T. nylanderi and T. parvulus, two species that are never parasitized by M. ravouxi. (Sorry guys. All these species go by their scientific names. But really, that just makes them sound all the more mysterious, right?). The researchers took all their ant colonies back to the lab and housed them in specialized plastic boxes (i.e. scientific ant-farms).

On the day of the tests, the scientists removed a single pupa (kind of like an ant-toddler) from one nest and placed it into a different nest of the same species or back in its own nest. They did this for colonies of both non-host species and for colonies of host species T. unifasciatus that were not parasitized at the time. Then they counted how many times the workers bit the pupa (an aggressive behavior) or groomed the pupa (a caring behavior).

Workers from all three species bit the pupa that was not from their colony more than they bit their own colony’s pupa. But the T. unifasciatus (the host species) were even more aggressive to foreign pupa than the other species. And only the T. unifasciatus withheld grooming from the pupa that was not from their colony compared to the one that was from their colony. Although all three species seemed to be able to tell the difference between a pupa from their own nest versus one from another nest, only the species that is regularly enslaved by M. ravouxi decreased care to foreign young. So that is what these ants do when they are not enslaved. How do you think enslaved ants respond to their own species’ young compared to M. ravouxi young?

A 1975 cover of Galaxie/Bis, a
French science fiction magazine,
by Philippe Legendre-Kvater.
Image from Wikimedia.

The researchers repeated the study using enslaved T. unifasciatus, placing either a pupa of their own species from a different nest or a M. ravouxi pupa in with their brood. Even though prior to M. ravouxi takeover the T. unifasciatus bit foreign pupa more than their own, after M. ravouxi takeover they didn’t bite foreign pupa of their own species or M. ravouxi pupa very much. Not only that, but they groomed the M. ravouxi pupa more than the pupa of their own species! Ah hah! Mind control!

This, my friends, is the kind of truth that science fiction is made from.

But how might this work? Ants born to an enslaved colony would be exposed to both their own odors and the M. ravouxi odors. Because ants learn the smell of their colony in the first few days after they emerge from their eggs, these enslaved ants would have a broader set of smells that they may perceive as being “within the family”. That would explain why the enslaved T. unifasciatus ants didn’t attack either the foreign-born T. unifasciatus or the M. ravouxi young, but it doesn’t explain why the enslaved ants provided more care to the M. ravouxi than they did to their own species. One possibility is that the M. ravouxi produce more or especially attractive odors to encourage the host workers to take care of them.

There is still more to learn about this system: How exactly may the M. ravouxi be hijacking the pheromonal systems of their host species? How are the host species protecting themselves from exploitation? I guess we’ll have to wait for the sequel.

Want to know more? Check this out:

Delattre, O., Chȃline, N., Chameron, S., Lecoutey, E., & Jaisson, P. (2012). Social parasite pressure affects brood discrimination of host species in Temnothorax ants Animal Behaviour, 84, 445-450 DOI: 10.1016/j.anbehav.2012.05.020

Snakes Deceive to Get a Little Snuggle

A lone red-sided garter snake.
Photo by Tracy Langkilde.

The red-sided garter snake is a small snake species with the largest and most northern distribution of all reptiles in North America. These northern ranges can get quite cold for any animal, let alone a reptile. Like most reptiles, they are ectotherms, meaning they regulate their body temperature largely by exchanging heat with their environment. If an animal gets almost all of its body heat from a cold environment, its body is also going to be cold… So what is a poor red-sided garter snake to do?

Red-sided garter snakes that live in the northern end of their range in Manitoba, Canada spend their cold-season (6-8 months of it) hibernating in underground dens called hibernacula. Tens of thousands of snakes may share a winter den and every spring, they emerge to mate and eat and do all the other fun things that snakes do when they’re awake. (If you would like to witness the spectacular sight that is the emergence of the garter snakes, it is occurring this month in the world-famous snake-watching Interlake region of Manitoba).

A whole lotta red-sided garter snakes in a spring-mating
frenzy. Photo by Tracy Langkilde.

When a snake first emerges from its groggy hibernation state its body is cold and movements are sluggish, which puts it at a high risk of predation from animals like crows and weasels. Females are generally at less risk of predation at this time because emergence-time is also sexy-time for this species and females generally find themselves in the middle of a writhing ball of already-warmed-up male suitors (appropriately called a mating ball). For the female, this both increases her body temperature faster (which will allow her to move faster sooner) and provides any would-be predators with many other snakes to choose from.

Female red-sided garter snakes produce a male-attracting pheromone (a chemical released by an animal that affects the physiology and/or behavior of other individuals of the same species). Researchers Rocky Parker and Robert Mason at Oregon State University found that the amount of pheromone females produce increases as the females hibernate from fall to spring. This pheromone is a blend of saturated and unsaturated methyl ketones (molecules responsible for many natural odors and flavors) and males are more strongly attracted to the unsaturated components. The chemical composition of the female pheromone also changes from fall to spring, such that female spring pheromones are dominated by these highly attractive unsaturated pheromone components. Presumably, the sexier the pheromone, the more suitors are attracted and the more benefits a recently-emerged female can acquire.

It seems that this smell-sexy-and-create-mating-ball strategy is a useful solution for recently-emerged females, but what about recently-emerged males? Parker and Mason collected courting male red-sided garter snakes and brought them into the lab. Then they either implanted them with estrogen (a sex hormone strongly involved in female sexual physiology and behavior) or did not (as a control group). Males with estrogen implants produced more pheromones, had higher ratios of unsaturated pheromone components to saturated pheromone components, and were more attractive to courting males. When the researchers removed the estrogen implants from some of the males, they became less attractive again. So in the lab, estrogen treatment of males makes them produce more female-like pheromones that other courting males respond to. This shows that males are capable of using this smell-sexy-and-create-mating-ball strategy, but do they use it in nature?

This graph shows the amount of courtship
received by females, "she-males", and "he-males"
when either cold or hot. Figure from Shine,
Langkilde and Mason's Behavioral Ecology
and Sociobiology Paper (2012).

Robert Mason at Oregon State University and Rick Shine and Tracy Langkilde at the University of Sydney, Australia collaborated to explore this relationship between temperature and male production of female-like pheromones. It turns out, male red-sided garter snakes in nature can and do produce female-like pheromones when they emerge from their den. Shine, Langkilde and Mason collected some of these males that were being courted by other males (the researchers refer to them as “she-males”). They also collected some males that were courting females (they called them “he-males”) and some females. They then exposed the snakes to different temperatures for 15-minute intervals and tested their attractiveness to other courting males. 

This graph shows the amount of courtship received
by "she-males" when cooled (open circles) and
heated (filled circles) for 15-minute intervals.
Figure from Shine, Langkilde and Mason's Behavioral
Ecology and Sociobiology Paper (2012).

 The researchers found that females were courted the most, “he-males” the least, and “she-males” were courted an intermediate amount. Interestingly, “she-males” only attracted courtship when they were cold (and their chances of survival could be improved by a mating ball) and their attractiveness shifted with every 15-minute shift in temperatures. How did they do this? 15 minutes is probably not enough time for a hormonal change to alter the pheromone composition enough to change attractiveness so drastically.

An important clue comes from the composition of the pheromones themselves. Remember that red-sided garter snake pheromones are a blend of saturated and unsaturated methyl ketones and males are more strongly attracted to pheromones that have a high ratio of unsaturated components to saturated components. Well, saturated and unsaturated fats respond differently to cold: Unsaturated fats (like cooking oil) remain a liquid at cooler temperatures, whereas saturated fats (like margarine) become solid. Solids are less volatile than liquids, which makes them not smell as much. Shine, Langkilde and Mason hypothesize that the ratio of unsaturated to saturated ketones is lower in “she-males” than in females. In the cold, the high amount of saturated components of the “she-male” pheromone is turned off, which raises the ratio of unsaturated to saturated ketones, making them attractive. As the snake warms up, the saturated components of the “she-male” pheromone is turned on, which lowers the ratio of unsaturated to saturated ketones, making them unattractive.

Remarkably, male red-sided garter snakes can change their pheromones to mimic or not mimic females in response to brief changes in temperature. How cool is that?

Want to know more? Check these out:

1. Shine, R., Langkilde, T., & Mason, R. (2012). Facultative pheromonal mimicry in snakes: “she-males” attract courtship only when it is useful Behavioral Ecology and Sociobiology, 66 (5), 691-695 DOI: 10.1007/s00265-012-1317-4

2. Parker, M., & Mason, R. (2012). How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes Journal of Experimental Biology, 215 (5), 723-730 DOI: 10.1242/jeb.064923

3. Parker, M., & Mason, R. (2009). Low Temperature Dormancy Affects the Quantity and Quality of the Female Sexual Attractiveness Pheromone in Red-sided Garter Snakes Journal of Chemical Ecology, 35 (10), 1234-1241 DOI: 10.1007/s10886-009-9699-0

4. For an awesome blog about social snakes from a researcher’s perspective, go to http://blog.socialsnakes.org/ (or http://www.public.asu.edu/~mamarell/ for more information)