Sad but true: Barnacles (critters who spend the majority of their lives with their heads glued to a hard surface) may be getting more action than you are.
Of course, that depends on how you quantify “action.” Barnacles have a fairly short mating season—compared to our non-stop mating season—but they cram a whole lotta nooky into the time they’ve got. Common barnacles (Semibalanus balanoides) get busy—very, very busy—in early November*. Scientists have observed as many as six males copulating with a single female simultaneously, each male inserting his penis up to 10 times within a 100 minute interval. Tetraclita japonica, a common acorn barnacle that mates from late June to early August, is even randier. Researchers counted 11 males copulating with a single female and a total of 582 penis insertions during the female’s eight and a half hour mating bonanza.
Hold on. Before we proceed with our discussion of barnacle sex, there’s something you should know about these crustaceans. Males aren’t always males and females aren’t always females. In other words, barnacles are simultaneous hermaphrodites—always ready to be either male or female. In observing T. japonica, scientists watched one barnacle mate as a female and then, three hours later, as a male, while another mated first as a male and then, a little more than three hours later, as a female. It just so happens that these two barnacles mated with each other twice, once when the first barnacle was a female and again after they changed sexes.
Now back to barnacle sex and the big question: How does it work? Most sessile organisms (critters that spend their lives glued to something else) just shoot their goodies into the water and hope for the best. But barnacles get it on—and even choose their mates—thanks to the magic of the barnacle penis. Actually, it’s not magical at all. It’s just really, really long and covered in chemosensory bristles. The bristles allow functionally male barnacles to “sniff out” attractive barnacles that are acting as females, while the go-go-gadget penis allows barnacles to mate with individuals that aren’t right next to them.
Barnacle penises can be up to ten times the animal’s body length, making barnacles the most well endowed animal in the world (ratio-wise, obviously). Impressive, yes, but such a long schlong is also a liability. They can’t just wave that thing around in the pounding surf without doing some damage. So they don’t. Barnacles on wave-battered shorelines have shorter, fatter (and therefore sturdier) penises than their counterparts in calm intertidal areas. And, barnacles moved from a tranquil shoreline to a wavy one—or vice versa—will adapt their penis shape accordingly.
How do we know so much about the sex lives of plankton-eating critters that glue themselves to rocks, boats and whales? Scientists watch them, they measure them, they move barnacles from one site to another…and when they want to figure out if relaxed penis length is a valid indicator of maximum penis length they use what we believe should be a world-famous methodology known as “artificial inflation of barnacle penises.” Here’s how it works:
…The soma was then cut between the first and second pair of thoracic legs, inserted onto the tapered end of a seawater-filled plastic capillary tube (1.09 mm in outside diameter, 0.38 mm in inside diameter and approx. 25 mm long) and carefully glued in place (Krazy Glue, Elmer’s Products, Columbus, OH) while keeping the penis tissue moist. The capillary tube was then inserted onto the end of a hypodermic needle (0.5 mm in outside diameter and 0.2 mm in inside diameter) and fitted onto a 10 ml plastic syringe filled with seawater. The penis and remaining feeding legs were positioned in seawater under a dissecting microscope. The penis was oriented perpendicular to the field of view, and pressure was applied to the syringe to slowly inflate the penis until (i) the glue failed, (ii) the soma tissue or cuticle ruptured, or (iii) the penis inflated fully. Full inflation was recorded when additional pressure on the syringe failed to extend the penis further and all annulations of the penis cuticle had disappeared. At this point, the penis was photographed again. This process was repeated for approximately 20 individuals per site until we had achieved full penis extension for three individuals from each population. (Neufeld and Palmer 2008)
That’s right. They inflated the penis until (1) the Krazy Glue failed**, (2) the barnacle’s penis exploded or (3) the artificial inflation procedure actually worked.
*Once the mating season ends, the barnacles molt and discard their penises. They grow back—slowly at first, and then rapidly in September and October so the barnacles are ready for action in November.
**and perhaps when the glue failed, the penis shot across the room like a deflating balloon. (This effect isn’t documented in the paper. That’s just how we picture it.)
HOCH, J. (2008). Variation in penis morphology and mating ability in the acorn barnacle, Semibalanus balanoides Journal of Experimental Marine Biology and Ecology, 359 (2), 126-130 DOI: 10.1016/j.jembe.2008.03.002
Hoch, J. (2009). ADAPTIVE PLASTICITY OF THE PENIS IN A SIMULTANEOUS HERMAPHRODITE Evolution, 63 (8), 1946-1953 DOI: 10.1111/j.1558-5646.2009.00668.x
Murata, A., Imafuku, M., & Abe, N. (2001). Copulation by the barnacle Tetraclita japonica under natural conditions Journal of Zoology, 253 (2), 275-280 DOI: 10.1017/S0952836901000243
Neufeld, C., & Palmer, A. (2008). Precisely proportioned: intertidal barnacles alter penis form to suit coastal wave action Proceedings of the Royal Society B: Biological Sciences, 275 (1638), 1081-1087 DOI: 10.1098/rspb.2007.1760
Research Blogging is giving out awards and, quite frankly, we’d really like one. Of course, to get an award, we need to be nominated—and to get nominated, we need you to nominate us (PLEASE).
Research Blogging (THE hub for all blog posts about peer-reviewed research) will be awarding cash prizes in several categories including Blog Post of the Year, Best Expert-Level Blog, Best Lay-Level Blog, Funniest Blog and Best Blogs in Spanish, Portuguese, German and Chinese. Clearly, we don’t qualify for the best blog in Spanish, Portuguese, German or Chinese, but we hope you’ll consider us for a more appropriate category (like Best Lay-Level Blog or Funniest Blog).
The Nitty-gritty: Nominations close on February 11, 2010. To nominate us, click here. You’ll need to provide “two links to exemplary posts and a couple sentences explaining why you think the blog deserves the award.” For your convenience, here’s a list of all our Research Blogging posts:
Altruism-On-Demand: I’ll help, but only if you ask nicely…
Climate Change May Make Fish Commit Predator-Assisted Suicide
On Thursday, scientists rescued a dog from the icy waters of the Baltic Sea…In December, a Portland, Maine “secret Santa” gave 100 strangers $100 apiece…And, so far, Americans have donated $29 million to American Red Cross Haiti relief efforts.
Humans are so darn nice. But how exactly did that happen? That’s what scientists at the Primate Research Institute at Kyoto University in Japan are trying to figure out. To gain insight into the evolution of human altruism (a demonstration of unselfish concern for others), the researchers looked at the altruistic behavior—or lack thereof—of chimpanzees.
The scientists placed two chimps into adjacent, transparent booths with a small window between them. Both chimps had access to a juice box (grape juice, of course), but the chimp in the first booth couldn’t drink the juice because the box was anchored to the wall and the chimp in the second booth couldn’t drink the juice because it was just out of reach. To get the juice, the first chimp needed a straw and the second chimp needed a stick.*
In one set of trials (the authors call these the “mismatched” trials) researchers provided the chimp in the anchored-juice-box booth with the stick, and the chimp in the just-out-of-reach-juice booth with the straw. To get at their treats, the chimps would have to get the tool from their neighbor.
The chimps did play nice, handing over the necessary tool to their neighbor in almost 60% of the trials. But seeing their neighbor in need of help only spurred the chimps to offer the necessary tools in 14% of the tool transfers. In most instances (75%), chimps didn’t hand over the tool until the other chimp asked for it—usually by sticking a hairy arm through the window. (In 10% of the successful tool transfers, a chimp stole the tool from its neighbor.).
In a second set of trials, the scientists gave one chimp a juice box either anchored to the wall or just out of reach, while the other chimp had the tool necessary to get the juice. The tool-holder gave the tool to the juice-drinker 90% of the time, 75% of those transfers occurred after the juice-drinker asked for the tool.
This second set of trials led researchers to claim that the transfers were altruism-on-demand and not a form of barter or I’ll-scratch-your-back-if-you-scratch-mine behavior. In theory, the chimp with the tool and no juice had no reason to expect any form of reciprocation when it handed over the tool to the neighbor, which it did at roughly the same rates as in the mismatched trials. (The researchers acknowledged, however, that this still didn’t rule out the fact that the chimps could be collecting IOUs that would get paid back at some future, yet-to-be-determined time.)
Scientists think that altruism-on-demand may be how humans first started helping each other. It’s a fairly efficient way to make sure your help (which usually costs you something in terms of time and effort) is actually needed. But altruism can be a tricky thing to pin down with absolutes. In similar research done at the Planck Institute in Germany, chimps spontaneously offered to help researchers that were clearly struggling to reach a toy or object. No need to ask for help.
So why do chimps consider humans more help-worthy than other chimps? Is it another form of altruism or do they look at humans as providers, and so know which side their bread is buttered on? Couldn’t the long-term IOU be enough to explain why the chimps were willing to help out a neighbor when they had no chance of getting juice for themselves?
As with any study involving a concept such as altruism, with its moral and ethical components, it can be really tough to know exactly what it is you’re observing: a good Samaritan or a savvy businessman.
To watch the full video of the trial, click here.
*The second chimp could pick the juice box up and drink out of it like a cup.
Yamamoto, S., Humle, T., & Tanaka, M. (2009). Chimpanzees Help Each Other upon Request PLoS ONE, 4 (10) DOI: 10.1371/journal.pone.0007416
In a recent paper examining the rate of improvement in top performances by track and field athletes and swimmers, Berthelot et al. write:
“The recent progression period in swimming results owes much to the introduction of swimsuits. This new technology, allowed by FINA in 1999, enhances hydrodynamic penetration and largely reduces drag forces.”
The authors conclude that the progression of human performances in these sports may soon reach its limit. Interesting, but what’s more disconcerting to me is that, according to the authors, I spent the majority of my swimming career swimming naked—and I didn’t even know it.
The paper is available here.
Berthelot G, Tafflet M, El Helou N, Len S, Escolano S, et al. (2010) Athlete Atypicity on the Edge of Human Achievement: Performances Stagnate after the Last Peak, in 1988. PLoS ONE 5(1): e8800. doi:10.1371/journal.pone.0008800
Remember the tale of Nemo (the juvenile clownfish that was fish-napped by a dentist) and Marlin (Nemo’s dad)? Marlin braves the open ocean to find Nemo, meeting a whale-speaking blue tang and a few non-piscivorous sharks along the way. Of course, Marlin and Nemo are reunited (it’s a Disney movie), but could a little clownfish really survive such an adventure without getting eaten?
It depends on the conditions. Scientists at James Cook University in Australia found that settlement-stage orange clownfish larvae raised in an aquarium with normal water conditions* had mad predator avoidance skills. To test the larvae’s ability to detect and avoid predators without killing their test subjects, the scientists used a flow chamber with two parallel streams of water moving at identical flow rates. One stream of water came from a tank with clownfish predators and the other came from one with non-predatory fish. When the scientists released the larvae into the flow chamber, the fish (which had never been exposed to predators) immediately swam away from the predator-tainted stream of water.
This innate survival skill is just as critical for an itty-bitty fish looking for a home on a coral reef as it was for an animated fish looking for his son. Ya see, larval fish typically settle on a reef at night during a new moon when there is very little light. They can’t rely on their vision to identify safe places to settle, so they have to sniff out a safe place to park instead.
That sounds easy enough for a critter hard-wired to sniff out and avoid predators…or not. The scientists raised another set of settlement-stage orange clownfish larvae in an aquarium with more acidic water (7.8 pH and 1000 ppm CO2) designed to mimic the conditions that could occur by 2100 under a business-as-usual scenario. These fish didn’t exhibit the mad predator avoidance skills of their normally-raised counterparts. In fact, the larvae raised in the more acidic water displayed stellar predator-assisted suicide skills, swimming towards both streams in the flow channel.
If ocean acidification does occur as predicted and clownfish respond to the increasingly acidic conditions as they did in this experiment, boy, are they screwed. It’ll be a miracle if Nemo’s great-great-great-great-great-great grandchildren survive long enough to claim a spot on a reef, let alone survive a Disney-esque adventure.
Of course, ocean acidification isn’t the only side effect of our little CO2 problem. We’ve got climate change to worry about too. And climate change, as it warms our oceans, may make fish pissy. Who cares about a hot pissy fish? Well hot pissy fish get eaten. And if all the fish are pissy and they all get eaten, well, there goes the neighborhood.
In a recent study, scientists studying personality traits in two species of juvenile damselfish from the Great Barrier Reef found that aggressiveness, boldness and activity rate varied with small changes in water temperature. With just a 1-2°C increase in water temperature, some fish became up to 30 times more aggressive, bold and active while the personality of other fish barely changed. The fish that get pissier in warmer water may be on to something, the scientists theorize. In warmer water, fish have to expend a lot of energy to stay cool, leaving them with less energy to grow. The scientists suggest that the pissier fish may be increasing their rate of food intake to give them enough energy to maintain their growth rate in the warm water.
These 1-2° temperature fluctuations occur naturally throughout the day, but more dramatic fluctuations may occur as the oceans heat up. Toss in an inability to smell a predator and we’re destined for an ocean full of reckless, hyperactive fish. Just what our fisheries need.
*The normal water had a pH of 8.15, the current average pH of ocean water near the surface.
Dixson, D., Munday, P., & Jones, G. (2010). Ocean acidification disrupts the innate ability of fish to detect predator olfactory cues Ecology Letters, 13 (1), 68-75 DOI: 10.1111/j.1461-0248.2009.01400.x
Biro, P., Beckmann, C., & Stamps, J. (2009). Small within-day increases in temperature affects boldness and alters personality in coral reef fish Proceedings of the Royal Society B: Biological Sciences, 277 (1678), 71-77 DOI: 10.1098/rspb.2009.1346
We’ve done our best to keep you entertained and informed this year. We’ve written about scientific research, environmental issues, alternative energy, coolness, weirdness and grossness and here’s what you liked the best*:
50 Ways to Eat Your Lover/Brother/Baby
Overfishing Simplified…Then Complexified
Cool Critter: African Wild Ass
Cattle, corn and finishing school
Fueling the Future…With Urine and Chicken Remnants
What are your favorites?
*This list is based on our WordPress statistics, which are only somewhat accurate. We excluded the two editions of the Scientia Pro Publica Blog Carnival we hosted, our post on Coconut Crabs (we suspect most people are looking for a recipe, not a cool critter) and Tits and Boobies (let’s face it, at least 90% of the people who land on that post aren’t interested in reading about birds).
We’re both biologists, but we didn’t pay much attention to ducks until five mallards moved into our pond last spring. At first, the ducks (three males and two females) kept to themselves, each staking out a little smidgen of our puny pond as its own. They ate—sticking their cute little duck butts up in the air—and paddled around quietly, confirming our perception that ducks are cute, but not all that interesting.
And then things got interesting—and ugly. One of the females disappeared, leaving three males and just one female. The randy males chased the seemingly helpless female around the pond, across the lawn and even into the air. For days, they quacked and pecked at her until they finally tackled her in the water. There was a whole lot of splashing and a frenzy of quacking and flailing wings as the males forced the female underwater. This was what duck researchers call “rape flight”—what most people call “gang rape”—and is apparently quite common for mallards.
After the rapes, the ducks disappeared. We were fairly sure the female was dead, but a month later a female mallard with 12 ducklings started traipsing around in the tall grass by the pond. Was it the rape victim? We have no idea, but recent research from Yale University scientists suggests that the ducklings were not the product of rape.
While other species engage in sperm wars, ducks face off in a war of genitalia. Most birds don’t have penises, but ducks…well, ducks are different. To score in rape flight, male ducks have evolved a foot-long penis capable of going from flaccid to erect in less than half a second. To fight back, female ducks have coevolved a spiraled vagina that prevents the “explosive” erection of undesirable suitors (i.e. rapists). Read all about it here.
Scientists recently discovered that the veined octopus is a tool user. The tool? A coconut shell. The use? Shelter.
The researchers watched octopuses off the coasts of Northern Sulawesi and Bali dig for coconut shells in the mud, clean the shell, then lift the shell and run away with it. When the octopus is ready to hunker down, it flips the shell over and climbs underneath. If an octopus finds two halves of a coconut shell, it climbs into one half and then pulls the other half over itself.
Check out the video here.
Welcome to the Epic edition of Scientia Pro Publica (a.k.a. the edition that almost didn’t happen). What makes this edition epic? Well, we do—we said it would be epic so it’s epic—but more importantly, the awesomeness of the science bloggers in this edition has reached truly epic proportions. Due to a SNAFU with the automated submission form, we only had one submission going into the weekend. A one-post carnival just isn’t “epic” so we begged our fellow science bloggers to re-submit their posts over the weekend. As you can see, they came through with epic awesomeness…
Anthropology/Evolution/Raptors are cool
In Projectile weapons and carnivores, DeLene reports on a Duke University scientist’s theory that projectile weapons (and the ability to throw them) enabled modern humans to out-compete Neanderthals and kill off all of Europe’s large carnivores.
Eric Michael Johnson of The Primate Diaries writes that Ardipithecus is not a missing link! He says that referring to Ardipithecus as a “missing link” (as many media outlets have done) is “like referring to a medical breakthrough in the treatment of lung disease by using Galen’s view that it caused a “reduction of phlegmatic humours” in the chest.”
Did you know that most raptors kill their prey by constriction? This is just one of the cool things I learned from John Beetham’s post about how raptor talons fit their prey. Apparently, some raptors kill their prey by striking them at high speed and some merely hold their prey still (while the prey is alive) as they pluck and eat it. One more cool raptor fact: falcons have a tooth-like projection on their beaks.
Conservation and Management
Jeremy tells us how not to manage overfishing in Law of unintended consequences, coconut edition. To give fishermen an alternative source of income (and hopefully reduce pressure on the country’s reef fish), the government of Kiribati subsidized the coconut oil industry. It didn’t work out the way the government planned…
Mike introduces us to a new way to count birds in Counting Birds: will microphones replace nets? He reports that ecologists have developed a system that uses birdsong to estimate the size of bird populations.
Gunnar Engblom reports that DNA from Darwin’s expedition may help save the critically endangered Floreana Mockingbird in Floreana Mockingbird Restoration.
In A New Look, I wrote about our new doormat and how it’s (kinda) protecting North Atlantic right whales and (sorta) helping Maine lobstermen.
Marine Science
DeLene writes about a recent study that examined the effects of ocean acidification on shelled marine organisms in Acid ocean test looks to the past. Under the experimental conditions, some critters responded predictably (with thinner shells), while others perplexed researchers by growing thicker shells in the more acidic seawater.
In lighter marine science news, Christina takes us on a virtual aquarium tour (that includes dogfish sex) in Fishy Fridays and Heather describes the mysteries of hydrothermal vents.
Plants/Agriculture
GrrlScientist writes about the discovery of the world’s smallest orchid species—the petals of the teeny tiny flower are only one cell thick, making the flower transparent—while Jeremy, from Agricultural Biodiversity asks: Do farmers know how to save seeds?
Chemistry/Biochemistry
Using a picture of a duck and a picture of a cat, S. Gould explains how Fourier transformations can be used to determine structures in protein crystallography in Lab Rat guide to Fourier Transformations. In a completely unrelated post, Lab Rat writes about using microbes to make second generation biofuels.
Heather explains that processing DNA is more complicated than the CSI team makes it look in A (hopefully) comprehensible explanation of something complicated…or why DNA is hard to read.
Medicine Past and Present
Romeo Vitelli has a new toy—a vintage Davis & Kidder Patent Magneto-Electric Machine for Nervous Diseases. According to Dr. Vitelli, the machine was quite popular in its day. It was used for medical purposes (to treat asphyxia, asthma, angina, impotence, constipation, “critical periods or turn of life in females” and diabetes) and for fun (at “phosphene parties” a group of people joined hands in a circle while touching the machine). Learn more in Singing the body electric.
In honor of Celiac Awareness Month (October), Eric R. Olson shares a profile of celiac disease. Many celiac patients choose to forgo formal testing for the condition…which brings us to Bora Zivkovic’s post about the importance of storytelling in medicine. In Lisa Sanders at UNC, we learn that physicians who interview a new patient correctly diagnose them after just an interview 75-80% of the time.
Reviews
It’s hard to stay up-to-date on the latest books about science and the environment. My co-blogger, Peter, recently reviewed Cradle to Cradle, a book that’s been out since 2002. His verdict: read it or stuff it in your favorite scientist’s stocking.
That’s it for the epic edition. The next edition of Scientia Pro Publica will be hosted by Bob O’Hara (assisted by GrrlScientist) at the hibernating blog, Deep Thoughts and Silliness on December 21. We’ll keep you posted on the status of the automatic submission form, but email submissions are always welcome (ScientiaBlogCarnival@gmail.com).
Attention Science Bloggers: We’re having issues with the automated blog carnival submission form. So…instead of using that “handy submission form,” please send an email with the link(s), your name and a brief summary of your post to ScientiaBlogCarnival@gmail.com. And if you submitted something using the automated form, please re-submit it via email. Thank you!
