Sunday, May 23, 2010

Garden in the Woods

Yesterday I went to a place called "Garden in the Woods" which is in Framingham, MA. It is an educational/recreational site operated by the New England Wildflower Society. It's devoted to native plants but that really means all of the US. A lot of it is specific to New England and they have a spot where you can buy New England plants for your garden but some of the plants are from other parts of the country. It's pretty aptly named because there are a lot of woodsy areas and you'll walk along and bump into a well groomed garden area. So...a garden in the woods. When I went to the Arnold Arboretum I wrote about how it felt a lot like a museum in a lot of ways and less like being in a real natural space. Garden in the Woods has its museum-like qualities as well: there are signs on a lot of the plants with common and Latin names, a lot of the grounds are very well manicured, you have to stay on paths, etc. But like I said there are also a lot of really woodsy areas that make it feel a little more like your standard nature center. Here are some great organisms I found while walking in the woods:

This is a club moss, not a baby conifer. I made reference to them when I wrote about bryophytes. They are primitive, simple plants related to other mosses.
A pink lady slipper orchid. Some people claim these are amazingly beautiful. I think they're a little weird looking. I was much more impressed with this next orchid:

Orchids are often bizarre and they are the most specious group of flowering plants. They often have unique relationships with single insect species pollinators.

I don't know the species of spider or plant but I think this is the coolest shot I got yesterday. It has to be viewed in full screen to be fully appreciated so check it out in the photo gallery. I also made an edited version of this shot but I really can't tell which one I like more. I'll put up both versions in a future post.

This is the flower of the pitcher plant species that lives in the Eastern US. Pitchers are carnivorous plants that have modified leaves that form a "pitcher" which traps insects.

A small frog lying on a very weird flowering plant called the golden club. None of the shots I took directly of the plant came out very well but this little frog was apparently feeling pretty photogenic.

A flame azalea, a Rhododendron species. I did not have the wits or the camera to capture it but I saw a hummingbird pollinating this plant.

New England Wildflower Society has a strong conservation message. They especially promote the use and appreciation of native plants. On the other side of the coin they try to educate about the troubles associated with invasive plant species. Then they lock those species up in invasive plant jail. Twenty years to life for disabling local ecosystems.

And who can resist an ant. Not me.

Aphids Mimicing Fungi

So as I was putting those pictures up from my yard the other day I did some quick research and found a really interesting bit of information about those red Aphids. They are pea aphids, the same species actually as those common green aphids. It appears that there are two forms of this species and the red one has managed to adopt a gene from fungi that allow the insects to synthesize carotenoids.

Carotenoids are bright red pigments and they are usually only found in plants and fungi, not animals. Animals will use carotenoids, often to display their fitness to potential mates, however. Take the cardinal. The male cardinal's color comes from his diet. He has to work hard to obtain foods rich in carotenoids to make his feathers brighter than all the other male cardinals around so when it comes time for the females to pick a mate they will choose him. It's a sign that he's healthy and strong and able to spend a lot of time foraging. So he'll be able to be a good dad and help out when the babies come. Plus he has strong genes and every mom wants their children to have strong genes.

I could only find the abstract for the paper and I'm really tempted to pay for the full article because it leaves some big mysteries. The abstract states that the red color "influences their susceptibility to natural enemies," but I'm wondering if that means birds and other animals are more likely to eat them since they contain coratenoids? Is there some advantage that the abstract does not state? What's the selective advantage? And also how the heck did those fungus genes get in there? Parasitic red fungi? I know that our genome is littered with genes from other things but those are mostly from viruses which makes sense.

So if you have any more knowledge or if you're somebody with maybe a background in genetics and have a better understanding of this stuff, please, drop me a line.

Saturday, May 22, 2010

Friday, May 21, 2010

More Backyard Biodiversity

I know: I've talked about it a lot. But it's the kid in me. I can't resist pointing out how many cool little creatures there are in one tiny plot of city yard.

These are red aphids.
And a little closer up.
See the beetles?
A little closer.
It totally lost its resolution but that gives you an idea of what it looks like.
And a spider guarding her (or possibly his?) eggs. You should really look at this one in the photo gallery, you can really see the spider's many eyes.

Salt Water Aquarium Hobby As a Window into Science Education

I was talking with a visitor at the aquarium a few days ago and he started asking me about maintenance of his salt water tank at home. He said he was having trouble with it but unfortunately this is an area of which I basically have zero knowledge. Even though I stand near salt water tanks for many hours I have not absorbed the intricacies of how to take care of them by osmosis (science pun intended).

Though I couldn't help this man and though he didn't seem particularly interested in the natural history of cuttlefish (of course to my chagrin) it did get me thinking...people who decide to try keeping salt water tanks engage in their own science education in a way a lot of people don't and perhaps this hobby could or should be promoted. He was using words like nitrates and bacteria and was very clearly aware of what was going on in the water. Even if he didn't have a firm grasp of exactly what those things were he was using a vocabulary that the average American doesn't have. He also had a different perspective on things the average person does know about: Most people seem to be firmly rooted in the idea that bacteria is always a horrible thing, lurking, waiting to make us and our children sick.

There are issues with sustainability but I am a believer in using aesthetics and appreciation to cultivate both learning and stewardship. If we as science and environmental educators encourage people to practice the hobby responsibly perhaps more people will make a first step towards developing more sound knowledge of ecosystems. Once I learn how complex it is to take care of a little 40 gallon salt water tank it makes the cognitive leaps towards a firm understanding of the complexity of real ecosystems less difficult. Once I come to appreciate the beauty of the fish or invertebrates I keep at home the more likely I am to care about the ones in the wild. Or so my theory goes. Thoughts?

Saturday, May 15, 2010

A True Bug?

I think this is an insect in the order Hemiptera which are collectively known as true bugs. I found it while walking in the Blue Hills today. I don't know exactly what it is but thought it was one of the better photos I've taken in a while.

Wednesday, May 12, 2010

Plethodon cinereus

Finally! More local wildlife! We find these little guys, the eastern red back (or backed depending on who you ask) salamanders under bricks in our yard through late spring and summer. They were out pretty early this year and I took this photo a few weeks ago. They aren’t the easiest critters to shoot because their little legs are so tiny that they often get lost in the dirt. But they don’t move much when exposed…maybe they’re afraid of giants.

They are widely found in eastern North America: West to Missouri, South to North Carolina, and north to southern Quebec. They have no aquatic larval phase, very unusual for an amphibian, and so have colonized much of the eastern woodlands. Apparently 94% of amphibian biomass in New Hampshire is made of eastern red back salamanders. Not that amphibians are everywhere or particularly hardy creatures but I’m sure there are a fair number of frogs and toads living in NH woodlands.

They are an important part of the ecosystem both as a predator of vast amounts of invertebrate species including centipedes and larval insects and also as a food source for snakes, mammals and birds.

One thing I was wondering, which finally prompted me to do the research for this post, was how they would fair with this strange weather we’re having. It was quite warm for a while and they came out and now it is cold again, even freezing. But unlike many other amphibian species they do not seem to estivate or hibernate. During winter they stop shedding and have special body chemistry that keeps them from freezing. They will burrow underground and feed on insect eggs. Any time it gets warm enough, even in the middle of winter, they will come out to scavenge. So I guess they little guys are probably fine and have just burrowed back beneath the garden. One more headcount in the yard’s biodiversity.


Animal Diversity Web: University of Michigan Museum of Zoology

The Horseshoe Crab Diaries: Pt. 1 in Which Paul Asks an Expert About Their Eyes

Two nights ago I had a chance, along with several colleagues, to go out to dinner with Bill Sargent who was speaking that night at the Aquarium's Lowell Lecture series. Mr. Sargent is currently a consultant for NOVA, an author and has been the director of the Baltimore Aquarium, a professor and a researcher at Wood's Hole. He was talking about how climate change has affected the community on Cape Cod and so most of our conversation revolved around climate change and how to communicate these issues to the public.

About halfway through dinner, though, one of the senior educators who was there with us turned to me and said "Oh, by the way, Bill is also an expert on horseshoe if you have any questions..." As I have alluded (read: expressed firmly and directly) I love horseshoe crabs. I also spend a lot of time with them at work. And the one thing that has continued to irk me is that no one can seem to give me a straight answer about how many eyes they have. So I asked: "Can you tell me how many eyes they have?"

Apparently the true number is 9. Most sources I have read fall into two camps: that they have ten and that they have some unknown number higher than ten. But Bill seemed sure: they have nine. So they would be: two compound eyes, the most recognizable eyes, lateralized on their shells, three "simple" eyes towards the front of their shell (children often think this is the HSC's nose...of course these animals have no nose at all...but they do taste with their feet like many other arthropods), one "eyespot" on the end of the telson (tail) and three "vestigial eyes" on the ventral side (bottom) of their shells. These final eyes were the ones I was the most skeptical about. Really? Why would they need eyes on the bottom of their shell when that part of the body is facing into sediment most of the time?

Well, he had an answer for that too: Allegedly the ancestors to the HSC would spend a lot of time swimming upside down. They used their lateralized compound eyes for directing themselves and orienting towards the bottom but they needed eyes on the bottom because that is where their mouths are and they were hunting surface-dwelling insects. Now, after millions of years of evolution, they are barely functional...but I guess they still get counted.

Sources tell me that they use the three simple eyes to detect levels of UV light which helps them stay in tune with the phases of the moon. They mate and lay eggs at the biggest full moon of the year in late may or early June and so they need to know when that is. Mr. Sargent, though, believes that they actually have a full year long internal biological clock with which they keep time. Because they spend so much time deep under the waves and even buried under the muck they really don't pick up most of the changes of the moon. That actually makes a lot of sense. Perhaps the simple eyes are there for back-up or resetting the clock should it falter.

I was so excited to talk horseshoe crabs with someone who knows so much about them. Hopefully I'll inadvertently stumble into more meetings with people like Bill.

Saturday, May 8, 2010

Friday, May 7, 2010

Fothergilla gardenii

A photo of a pretty flower's a nice day and I haven't posted a photo in a while.

Bathynomus giganteus

Bathynomus giganteus, the giant isopod, is quickly becoming one of my favorite arthropods. We have a few molts (the exoskeleton left behind when an arthropod sheds) at the aquarium and I love taking them out to tell people about the crazy creatures that live deep under the waves.

Many of us are familiar with isopods that we find in our yards: pill bugs or rolly-pollies as they are colloquially known are one of the only crustaceans to completely leave an aquatic habitat. There are terrestrial crabs but all of them have a marine larval phase. To my knowledge there are no other crustaceans that can live so far inland. But the pill bug's cousin, Bathynomus is truly giant by comparison and not long ago I was shown this great video illustrating the creature's size and eating habits: it is a truly important part of the sea-bottom ecosystem as it feeds on the decaying remains of large animals. Enjoy!

Wednesday, May 5, 2010

Food Aversion and Chemoreception

I’ve been meaning to look into the evolution of taste and food aversions in response to a question about why someone would dislike eating cucumber, a vegetable that is completely lacking in PTC, the compound found in Brussels sprouts, broccoli and other famously disgust-inducing foods. Frustratingly the two biology text books and the one cognitive science text book in my house have very little information on the senses of smell and taste. I think this is for a few reasons. First, the chemoreceptive senses, taste and smell, are still somewhat poorly understood by science. Second, we tend to favor vision and hearing because these are our “primary” senses which we use to understand our world. Our cognitive world is dominated by vision and audition in a way that makes our chemoreceptive senses seem almost like different things all together.

So the best answer I could come up with for why you would dislike a food that was not bitter is that you have been conditioned. You probably don’t even remember the incidents of conditioning as they more than likely happened in childhood and may have been subtle correlations between food and unpleasant sensations. I know for a fact though that many people are unable to eat foods that they ate when they had a cold, for example. So I imagine that it’s entirely possible to develop a life-long aversion through conditioning. Unfortunately I could find exactly zero information on food texture aversions. I imagine this could also have something to do with aversions to foods that do not contain PTC.

So even though I wasn’t able to find much on anything other than bitter molecule detection at the root of food aversion evolution what I did find was some interesting biological tidbits related to taste and smell. Taste and smell are essentially the same sense in that they are both examples of chemoreception or the detection of molecules and chemicals in our environments. The difference for us is that taste occurs in solutions and smell occurs when we detect molecules floating in the air. But for aquatic creatures there really is no distinction. Because every molecule they come into contact with is in solution they are both tasting and smelling at the same time. Also, for the most part, this is happening constantly. Skates, for example, have nasal passages above their mouths where water is constantly flowing. This allows them to continually monitor what’s in the water.

Another interesting chemoreception fact is that most insects and other arthropods do most of their chemoreception with their legs. This is one of my favorite facts that I share with people about the horseshoe crab but it extends to most other arthropods. They also tend to blur the line between tasting and smelling as they tend to have only one mode of chemoreception. Some can sense with antennae as well as legs and often will have specialized the use of their antennae to things like pheromones or other specific molecules. But the fly, for example, and the horseshoe crab do all their food selecting with their feet.

Hopefully I will find time to write more soon because I have some pretty good photos and want to share some info about salamanders and…more on horseshoe crabs. Let me tell you how amazing they are. Very!