Yesterday a really exciting thing happened -- our tarantula molted! We were also really lucky to get to watch close to the entire thing, and I've got both photos and video.

What's molting? It's when they shed their external skeletons. In the process, they also replace internal organs, such as female genitalia and stomach lining, and can even regrow lost appendages. This happens with spideringlings (very young tarantulas) as often as once a month, but an older one like our Rosie will molt every 1 or 2 years. Male tarantulas actually don't molt after they become adults, but Rosie is female so she will!

Science Explorer Mark was doing the morning rounds feeding and taking care of the critters when he found Rosie laying on her back. Mark knew exactly what that meant, since he's had tarantulas before. I went over to have a look and, after I got over a bit of squeamishness, it was pretty fascinating to watch.

Here is Rosie, the tarantula, laying on her back near the beginning of the process.

She's still pretty connected to the top layer, which is the old skeleton. Can you see her fangs? The new ones are on the left, and the old ones are on the right. It's hard to tell in this picture, but the new ones are all shiny and have very red tips, whereas the old ones are darker and looking old and dusty.

First it seemed like she scooted her body away. Then she seemed to be pulling her legs out of the old skeleton. Then she seemed to be pushing the old skeleton off of herself.

Here is a great side view of Rosie (on the left with all of her legs together) pushing the old skeleton off on the right before all of her "new" legs are free. The old legs are the ones sticking up all over the place.

Then once her legs were all out of the old skeleton, she was pushing the entire thing off of her. Here you can see the new legs are black and the old ones are more of a brown colour.

The main event took about 45 minutes to happen. It was pretty slow. After she was mostly out, it seemed to take her another couple of hours to finally get out from under the old skeleton and flip herself over. We are all so sad we missed Rosie turning herself over! But, here she is: old Rosie on the bottom of the picture (the belly is still facing you), and refreshed new Rosie on the top, right side up:

And, here's what Rosie's old skin looks like out of the habitat:

I took more photos, and they're here in the Flickr set with more descriptions.

I also took video! The neatest part about all of this is that Rosie doesn't really move around too much. In fact, until yesterday I'd never seen her move! I'm sure the Science Explorers have since they see her every day and take care of her, but as someone who just pops in to the critter cave occasionally, well Rosie is pretty quiet. So, even though the video below isn't very action packed, it is pretty phenomenal when you know how little these guys move around during the day.

Watch the second video here.

I encourage you to come on by to visit new Rosie and old Rosie! We'll have her old skeleton on display in the critter cave for as long as we can. Kind of appropriate our tarantula turned into "two" during Spooky Science Month, isn't it?

Stay curious,
Collette

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