Wednesday, December 22, 2010
Wednesday, December 15, 2010
Tuesday, December 14, 2010
Saturday, December 11, 2010
Tuesday, November 30, 2010
Friday, November 12, 2010
Thursday, November 4, 2010
I've just been learning about turtle "hibernation," or bromation. Lots of animals apart from those true hibernators can employ periods of deep sleep or vastly reduced metabolic activity. Freshwater turtles that live in parts of the world that freeze over have to go into such a state to survive the cold winter.
What they will do is usually drop to the bottom of a pond or lake. Unless frost line dips below the bottom of the pond the water will remain at 39 degrees F all winter no matter the temperature above because this is the temperature at which water is at its densest. So if it ever cools to below 39 degrees it will begin to float up and away from the turtle.
This might seem extremely cold but the turtle actually does just fine with it. The animal will also, as is the case with most forms of hibernation, lower its metabolism to an extremely low level. Many species' heart rates will fall to one beat about every ten minutes.
What I started wondering is: how do they breathe? Well they have specialized organs in their pharynx and near their anus that have a thin enough membrane that oxygen can be absorbed directly from the water. However, they are still unable to exhale. This means that lactic acid begins to build up in their muscle tissue. To compensate for that (and I think this is the most amazing part) calcium compounds from the shell will dissolve and enter their bloodstream, neutralizing the acid.
It's just wild to think, from a mammal's perspective, that all winter can be spent at the bottom of a lake, completely submerged in near freezing water. Evolution never ceases to amaze me.
Wednesday, November 3, 2010
Monday, October 25, 2010
The Horseshoe Crab Diaries Part Three: In Which Paul Learns Something New and Then Must Tell Everyone
Tuesday, October 12, 2010
Monday, October 4, 2010
I’m going to try something a little different today on the Network. I have limited my topics to either local species, generally accompanied by a photo that I took myself or musings on natural history education in general. Today I’m going to start a series that introduces organisms that are oddities, phylogenetically speaking.
Perhaps my most nerdy passion is learning about phylogeny. Phylogeny is essentially the study of relationships in the tree of life. The organisms I want to take a look at are those that have diverged in interesting ways from their close relatives.
So today’s featured creature: the shipworm. I’ve been thinking a lot about the word worm. It’s one of those words that, speaking technically, carries almost no actual meaning. It’s a descriptor of body type (long and thin) and before biologists were able to start the project of classifying animals based on their actual relationships instead of what they looked like it got used as a label for all sorts of things. So we end up still using the word “worm” today to describe at least four major phyla (annelids, polychaetes, nemerteans and nematodes) and probably more that I’m missing as well as a host of other creatures that aren’t part of any of those groups.
Image courtesy of the US Geological Survey
Like this guy here. The “shipworm.” Folks tell me he’s not a worm at all. He fits the description more or less, though. He’s long and thin. But this animal is actually a bivalve mollusk, meaning his closest relatives are clams, mussels, oysters, scallops etc. and most closely the geoducks and soft shell clams. But this creature has diverged away from the “normal” bivalve physiology by growing into an organism with an elongated body. It retains the two shells of other bivalves but these have been altered into a cutting or boring device at one end of the animal.
Shipworms are so named because they are well known by sailors to bore into ships’ hulls, destroying them in the process. Wood can become so concentrated with the burrows of shipworms that it becomes nothing but an empty husk, brittle to the touch. The family of shipworms has also been dubbed “termites of the sea.”
This behavior of drilling into wood serves two purposes. First is protection. The animal will remain inside its burrow and secrete a calcareous compound to line it. The second is nutritional. These mollusks actually consume the wood and live symbiotically with a bacteria that takes nitrogen from sea water and synthesizes proteins. They also extend their siphons into the water through the open end of the burrow both to breath and to supplement their diet with plankton.
Even though a single piece of wood can become almost completely saturated with shipworm burrows they never make them long enough to interfere with a fellow shipworm. They simply stop growing. So apparently they are not only fascinating but also really great at sharing!
So the next time you pass some drift wood at the beach inspect it more carefully and you may find the little holes left by these bizarre bivalves.
Chesapeake Bay Field Guide: http://www.chesapeakebay.net/shipworm.htm
Grave, B.H. Natural History of Shipworm Teredo Navalis, at Woods Hole,
Thursday, September 30, 2010
I am attempting to semi-triumphantly return to the world of actually posting on my blog. But of course the frustrations of photography tend to get in the way. I need to make time to actually go shoot and then when I do I realize after looking at the images that my camera was set on all the wrong settings. O well, some of them are actually passable.
Futuyma, Douglas J. (1998). Evolutionary Biology 3rd Edition.
Tuesday, September 28, 2010
One thing I am downright baffled by as I continue writing the Mycelial Network is how people who have real jobs maintain their blogs. I guess I’m just lazy. But not today!
It’s officially fall. The moon says so. And the leaves in my neighborhood have already started to change colors. This is one of those events, like that sun rising every morning, that we all expect. But how and why does this occur?
Chemistry of course! Most of us are probably familiar with one of the molecules in tree leaves that gives them their green color: chlorophyll. But tree leaves have other pigments in them as well from two major classes of molecules: carotenoids (I may have ranted about these when I talked about the red aphids. Carotenoids give most red things in nature their color.) and anthocyanins. These compounds aide the work of chlorophyll by absorbing additional wavelengths of light.
A quick note about color for those who’ve forgotten their high school physics: colors are produced by rays of light with different amounts of energy or wavelengths. So red, orange, yellow, etc. each have a very specific amount of energy associated with that color. When white light strikes an object some of those wavelengths are absorbed by the pigments in the object. The colors that are not absorbed are reflected to our eyes and that produces the color we see. For example: a red object is actually absorbing all or most wavelengths of light except for red. The red is then reflected to our eyes and we perceive that color.
So when autumn comes the days start getting shorter and the nights get longer. This begins to trigger trees’ response to get ready for winter. Deciduous trees’ leaves are not capable of surviving frost so they have evolved to drop them off to conserve energy during cold months and months of low sunlight. It’s simply not worth while to try to photosynthesize only a few hours a day. As this happens the chlorophyll begins to degrade but the carotenoids and anthocyanins remain, showing the pigments that were always present in the leaves but were unnoticed due to the presence of chlorophyll. Sometimes leaves simply turn brown and shrivel instead of turning a brilliant red, purple or yellow. This is because the other pigments have also degraded and waste material is building up in the leaves, giving them a brown color.
The range and intensity of the color change can vary greatly depending on weather especially rainfall and sunlight. These processes are still not entirely understood and scientists are working on figuring out the more precise patterns of autumn color change in leaves.
What other fall-related natural history topics would you like to see on the Network? Leave me a note and stay tuned for (hopefully) more from me soon.
University Of Wisconsin: http://scifun.chem.wisc.edu/chemweek/fallcolr/fallcolr.html
Science Made Simple: http://www.sciencemadesimple.com/leaves.html
Tuesday, September 7, 2010
Tuesday, August 24, 2010
I just realized it has been a very long time since I've posted anything. I was going to try to figure out more about this weird possible club moss but I was having trouble and I've been really busy so here's the picture at least. This is another photo from the white mountains.
Friday, August 13, 2010
Monday, August 9, 2010
Sunday, August 8, 2010
Saturday, August 7, 2010
Friday, August 6, 2010
I am very excited to bring you the next post covering my brief trip to the
So if the Ghost Flower (I think that’s the best name) doesn’t gather energy from sunlight like most plants how does it gather usable energy? Well this is the other reason I’m so excited to write about this plant. Instead of employing photosynthesis it taps directly into (any guesses?) the mycelial network!
These plants (there are actually many species of these flowers) are considered to be parasitic on the mycorrhizal fungus of the network but the energy (mostly in the form of carbon) that the plants use to power themselves is coming primarily from the photosynthesis of trees that are tapped into the network. Apparently the drain is so small that the trees, and thus the fungus, are “physiologically unaware” of the energy loss. Perhaps they’re pirates but the amount of energy is at such low levels that it’s almost negligible.
These flowers are found growing in unusually dark places in
Oh, and I’m pretty sure they’re haunted.
Friday, July 30, 2010
Wednesday, July 28, 2010
Last week I was camping in the White Mountains. Despite some rainy (and downright stormy) weather we managed to get some pretty stellar hiking in. I learned a couple things in my attempts to turn some of my experience into posts for the Network. First, I am terrible at shooting mountains. I'm sure I can learn but my familiarity with the very small and my lack of experience shooting them made it a somewhat fruitless attempt. The shot above represents the best of probably about 20 shots and still it doesn't capture the experience of being there in the mountains.
Sunday, July 18, 2010
Friday, July 16, 2010
Another local species! And an arthropod to boot! How lucky you are!
This is the caterpillar of the monarch butterfly, known for its relatively long migrations across parts of North and
Thursday, July 15, 2010
The Atlantic ribbed mussel is a common mussel species found on much of the shoreline of the eastern
Mussels are bivalves (meaning two shells) which are a family of mollusks. This puts them into relationship with snails, octopuses, squids and cuttlefish (in addition to a few other smaller families). Like all other bivalves (clams, oysters) these ribbed mussels have a muscular “foot” with which they are capable of crawling through the sediment. They typically will remain in one spot, however, unless their ecosystem changes drastically enough.
In fact mussels have the habit of holding themselves fast to stable objects such as grasses, rocks, other bivalves as well as docks and other man-made objects. They do this with something called “byssal” or “byssus” threads, strong, sticky threadlike structures secreted from their foot. This is what keeps mussel “clumps” held together and is both a strategy for keeping safe from predators (their shells aren’t as thick and hard as their cousins the clams) as well as for preventing themselves from being swept away by waves and tides. This also puts them in a mutualistic (symbiotic) relationship with marsh grass. The grass provides the mussel with an anchor to attach to and the mussels provide fertilizer in the form of waste products.
These mussels are typically found in marshy areas with just their very tops poking out of the mud. I found these in West Dennis on
This is a hilarious quote from the
Edible yes. Pleasant, no.
The Assateague Naturalist: http://www.assateague.com/ribbed-m.html
The EOL: http://www.eol.org/pages/449853
The Chesapeake Bay Field Guide: http://www.edc.uri.edu/restoration/html/gallery/invert/ribbed.htm
Tuesday, July 13, 2010
The exhibit is fantastic and has all the elements of a great children’s museum play space. It’s outdoors, which is awesome, and contains weatherproof costumes of different animals such as a spotted salamander. There’s also music involved in the form of an underground marimba.
As always the artwork is phenomenal. Here’re a couple examples:
a star nosed mole!
But the best part? Latin names!
This really made my day and represents a philosophy that I share that it’s never too early to introduce folks to real hard science. Even if they don’t really understand what those funny words mean they are getting primed just by seeing them. Later in life many enthusiastic PCM players will still have those fond memories of playing in Underland and reading those Latin words. Not only will they be more ready to understand their real meaning, having been exposed to them early, but this will bring them back to what can only be a magical and fun experience: playing at the PCM. I can only imagine that will help to fill science learning later in life with memories of play and exploration. Just fantastic.
Look forward to a couple of new posts about local fauna.
Tuesday, July 6, 2010
Yesterday morning, as I got my bike out to ride to work, I came upon this snake lounging on the stone steps coming down from our back yard. I didn’t have time to leisurely shoot this reptile because, well, I had to get to work, so the pictures aren’t amazing. But at least I documented another vertebrate. I think that’s two!
So T. sirtalis sirtalis, the Eastern Garter Snake is a subspecies of the Common Garter Snake. The term subspecies gets a little hard to define (considering species is hard to define) but it’s basically another distinction under species. There’s not a whole lot to say about them: they’re little snakes that live in most parts of the
One somewhat interesting thing about these snakes is that they give live birth. This is called viviparity and when I was in grad school I found that there’s actually a whole lot of squamate reptiles (snakes and lizards) that do this. I think a lot of people assume that mammals are the only ones who give live birth but sharks and reptiles also employ this strategy. It’s evolved a good number of times over the last few hundred million years.
Friday, June 25, 2010
Thursday, June 24, 2010
This post was going to be titled “Not For the Faint of Heart” but I didn’t actually capture the image that was going to headline it. I was out for a walk yesterday looking for things to shoot (Bang! Bang!) when I cam across a dead bird full of green flies. I watched them seethe for a bit, brought my camera up, lowered it, watched a bit longer, walked away and then walked back. I had decided I wanted to shoot it but as I came back I disturbed the flies and they alighted.
Why didn’t I just shoot them? They were animals. And as I first came upon them they were undisturbed. I really could have had a fantastic image of them. But I kept thinking about reactions to an image I have of a dead bird. It’s not particularly beautiful and was unfortunately killed by my pet cat and not from something (more) natural. But most people hate it. So I decided not to capture another dead bird.
But as I was walking away the first time I thought about how similar this scene was to every other scene of organisms gathering resources, organisms getting energy from their environment. I resolved to capture that just as I would a honey bee landing on a flower. As I walked away the second time, having failed to get my image, I thought more about how we impose our own morality on nature, how we anthropomorphize even a pile of flies. There was no right or wrong in that dead bird. It was just a pack of organic compounds waiting to be reacquired by the ecosystem. The flies were merely obliging.
Niche theory, in biology, states that when there are resources, when energy is bound up somewhere in the ecosystem, eventually an organism should come along in evolutionary history to take advantage of that source of energy. We see this in the small changes of cichlid fishes’ pharyngeal jaws (jaws within jaws, see this x-ray of a moray eel), we see it in the rise of pollinating insects (once flowers appeared so did creatures that took advantage of them) and we see it in flies and other animals like burying beetles that use the cadavers of vertebrates as energy sources.
Probably something in us roots for the vertebrate and is sickened to see it crawling with arthropods (I've mentioned our innate nauseated response to creepy crawlies probably being an adaptive response to finding them in spoiled food). But there’s certainly nothing “moral” about the process. It’s just another niche to be exploited by another intrepid organism.
Tuesday, June 22, 2010
Sunday, June 6, 2010
Friday, June 4, 2010
Quite a while back when I was dealing with the natural history of arthropods you can find in your house I was asked to treat the housipede or house centipede. Finally, here it is. I don’t have a shot of this creature because I don’t see them to0 much and when I do it’s only for a second. They, like silverfish, move creepily quickly. But for those who aren’t familiar or haven’t heard the term housipede before you can check out the shots on the encyclopedia of life: http://www.eol.org/pages/1033083
House centipede is a term used to describe levels of taxonomic specificity all the way down to the species Scutigera coleoptrata and all the way up to the family Scutigeromorpha. To imagine that there’s an entire tribe of these creepy beasts running (yeah, running) around in our basements is slightly unsettling. This all started with my encounter with a spider and me singing the praises of finding wildlife indoors but the housipede is another flat, many-legged crawling critter I’d prefer stay outside.
The housidpede is indeed a member of the arthropod group of centipedes. Its first pair of legs has been modified into fangs for dealing with its prey. This is typical of centipedes. All (all) centipedes bite. It’s just a matter of how painful a bite they can deliver that classifies them as harmful to humans or not. (A quick tangent: I really like to make this clarification with jellies. All jellies sting but certain kinds, like the moon jellies that are common in
Housipedes (or the specific species S. coleoptrata) are thought to be native to the
I know you’re all probably sick of hearing about the oil spill in the
Directly related to that, each time I have a conversation with a visitor at work it goes directly back to the animals. I try to link it to personal consumption, reducing ones own use of petroleum products but it has seemed (this is my personal experience) that the words don’t hit home. I’m glad they care about the kemp’s ridley sea turtles and other charismatic creatures of the Gulf. But if they aren’t able to see that their own actions are directly linked with the spill…well I’m just not sure we’re making progress.
And lastly, I was going to write about children and conservation this morning and how, for the most part, it is easy to recruit younger folks into the movement. Children have a seemingly innate love of animals and that can easily be translated into passion (though possibly blind passion) for environmentalism. With this issue (the spill) I’m not sure it works that way at all. Children are only consumers of fossil fuels indirectly through their parents. Sure we could encourage (and often do) that they talk with their parents about these issues but ultimately the grown ups are the ones making the big decisions about what car to buy and what house to buy and how to heat the home and, much more importantly, what stuff and what food to buy. I don’t have the heart to advocate that a child not buy a plastic action figure. I know. I hate plastic. I hate useless stuff. But children love action figures. Heck, I still have a hard time resisting them. For whatever bizarre reason the Star Wars, Comic Book, LOTR nerd has a hard time being confronted with plastic reproductions of his/her favorite characters. Honestly a child’s happiness is worth a little more plastic in the world. It’s a though scale to weigh.
OK, that’s my oil spill rant. You won’t be hearing any more about it from me. I get the inclination through the Marine Educator’s listserv and coworkers that some have had slightly more positive educational experiences using this ugliness as a teachable moment. Stories, please!
And I’ll try to bring you something a little more cheery by the end of the day. Even if it’s just a photo.