The Photosynthetic Sea Slugs, and Horizontal Gene Transfer

The sea slugs known as Elysia chlorotica are certainly a strong contender for my favourite animal.  They are born clear, and they feed on algae for nutrients and energy.  But, they poke little holes in the turgid algae pieces with their tooth, and suck out the individual chloroplasts.  The chloroplasts do not get digested, and instead migrate to the animal’s skin, where the animal has gained the ability to keep the chloroplasts alive inside its animal cells (not in-between, but inside).  The chloroplasts then photosynthesize using sunlight, and produce energy for the slug’s cells.  The chloroplasts make the slug’s skin green, and indeed the slug has evolved to take on a shape which maximizes surface area, in order to harvest as much sunlight as possible.  The adults resemble leaves for this reason!

Watch this video of the little guy sucking out the chloroplasts from a piece of algae:


These slugs were successfully kept alive in excess of a year in a tank with absolutely no caloric input in the water, and with nothing but a UV “grow lamp.”  Their growth was very slow during this time, but this indicates that an animal was capable of living entirely off of photosynthesis!  This is the only animal known to be capable of keeping the chloroplast endosymbiont alive. Continue reading “The Photosynthetic Sea Slugs, and Horizontal Gene Transfer”

Learning to Laugh

As a child, I did not smile or laugh as a response to the emotions I felt.  I would laugh in response to physical stimuli, such as when being tickled, but that was it.  This first presented a problem for me when I was enrolled in dance classes.  Each class had an annual dance recital, and as part of that performance we had to smile.

When I was first asked to smile during practice, I did my best approximation of a toothy smile, learned entirely through observation.  The teacher seemed satisfied by this attempt, but after a while of my consistently smiling in this way, some of the girls in the class told me quite frankly, “You smile weird.”  Indeed I can hardly blame them, my smile was weird.  Almost terrifyingly so.  I would pull back my lips and show both rows of teeth, as big as I could, and for some reason I favoured the right side of my mouth.  I know this from looking at my old dance photos, which I’m now embarrassed to look at what I once thought was a totally normal smile.  In light of this new information, in order to perform the dance correctly, I decided to teach myself how to smile.

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Belize it or not, Steen is not at home

Belize it or not, Steen is not at home, please leave a message at the beep. I must be out, or I’d pick up the phone, where could I be? Belize it or not, I’m not hooooooome!

As promised, here is the post with the film photos from my trip to Belize with Doc. All photos were taken with the Lomography LC-A on Lomography color negative ISO 400 film.

My feets over the side of a sail boat, near Caye Caulker

Continue reading “Belize it or not, Steen is not at home”