Invertebrates in the news #1 - Bdelloid rotifers & Corynactis viridis

To keep you entertained about invertebrates when we are not in the field, I will write regularly about invertebrates that made the news recently. On the menu today: a summary of a story published today about rotifers and a video of a tiny sea anemone.

How do bdelloid rotifers do without sex?

There are less than 1% of all animal species that don't use sex at all to reproduce. And, for most of them it seems that they gave it up fairly recently. This suggests that, in the long run, species that do not use sex to reproduce end up extinct. By not reproducing sexually, species accumulate deleterious mutations, and cannot exchange mutations that could help them to adapt to changes in their environment -- such as new diseases.

Bdelloid rotifers are an exception, as it seems that they have been reproducing strictly asexually for tens of millions of years. A study published today in the journal Science by Wilson & Sherman sheds some light on the cause of this exception.

Bdelloid rotifers are microscopic animals that live in any kind of moist habitat all around the globe. In addition to their mode of reproduction, bdelloid rotifers are also exceptional in their ability to stay alive out of the water for up to 9 years (at any of their life stages). This ability might be one of the factors explaining why they do well without sex.

The authors of the study showed that staying out of the water for a few weeks reduced drastically the number of individuals killed by a pathogenic fungus. By staying dry for an extended period of time, they can get rid of the the fungus and reduce the selective pressure that these pathogens impose to these asexual rotifers.

More info on the ScienceNOW website and in the original paper.

Video of Corynactis viridis

Have a look at this video of this small sea anemone feeding on plankton. Note how it can change the shape of its tentacles and its mouth (in the center). This video has been filmed under fluorescent light and is played 1200 times faster.

'Corynactis viridis' from MORPHOLOGIC on Vimeo.

Welcome 2010

New year, new semester, and we are all back in Gainesville. And we have already had visitors. Carole Marshall is here looking at our collection of specimens from the Lake Worth/Peanut Island area. She has been diligently photographing shells from our dry collection. We have over 3500 from that area so she has had her work cut out for her.

Harry Lee came back to reprise his role of expert IDer, this time applying his skills to the snail family Terebridae.

We realized that with these new IDs, this will probably be the next group slated for subsampling and plating. A little recon revealed that many of these specimens are small and/or tightly retracted. I think next time we might suggest to Gustav a nice slug family that we should subsample. Dorididae anyone? Well, small and retracted isn't so bad right, at least they're not bivalves, those might present a real challenge. Oh right...

We've been doing the bivalves. I was manning the photo station yesterday when Nat saw me photographing the lovely Lioconcha pictured above. What does its pattern remind you of? If you said "a phylogeny" then you might need to spend a little less time with Geneious (I'm looking at you Nat).

It's true, we're still hooked on Geneious. Below, Jenna is giving Nate an adamant lesson, but they both look pleased with his Geneious-learning acumen.

Now that the semester has started again, the Cuke Team will be reassembled. Julie was previously pictured doing some solo work on ossicle slides, but now she will have company. You last saw JD working with Jenna at Geneious, but that was merely in order to add to his skills as a Cuke Team member. Here he and Laura cuke it up, preparing still more ossicle slides of the sea cucumber family Synaptidae.

Also, Sarah is back from Moorea, but she just can't seem to let go. She has spent much of her time lately compiling the field data into a spreadsheet that can be imported into the Biocode database. The massive collection effort in Moorea is part of the large, three-year Biocode project which aims to document the entire diversity of the island. All the data must be in exactly the right format and Sarah has spent countless hours staring at error messages trying to make it so. She seems so happy, it must be just like being back in the islands!

Art just got back from Ecuador, but I can tell that he was missing work while he was on vacation because he dove right back into drawing Alpheid details. Art has several new species that's he's in the process of describing for publication. It must be keeping him pretty busy because the packages arriving from Amazon.com have slowed to a trickle.

New for 2010, division uniform? Either that or Jenna, Sarah, and I are psychic. There's no other possible explanation for the teal shirts we all decided to wear on the same day this week.

Happy New Year everyone!

:) Mandy

Goodbye Derek!

I realize that it has been far too long since the last HQ update but in my defense, we have only recently returned from break, and our computers underwent some IT voodoo that rendered them problematic for a few days. Only one short week into the new year and we lost Derek. We knew it was coming, and we are excited for him about his internship on Dauphin Island, but we'll miss him nonetheless. Today, in his honor, we listened to the internet radio station he created and his favorite song "Party in the USA." Feel free to play "It's so hard to say goodbye to yesterday" while you look at the pictures below.

We briefly shared Derek with Invert Paleo, but even before then Derek dove in to help them with their tray delivery.

Ok, so Derek is wearing the same sweater in all the pictures below. They weren't all taken on the same day, it's just cold in the range! Here he is sorting through an incoming collection, or is it specimens to plate? I can't be sure.

Pictured below is part of Derek's adventure IDing portunid crabs. He looks happy, this one must have keyed out nicely.

And this is from his last day, still diligently working on the photographs of the specimens that will be sent away for DNA sequencing.

I did not get any pictures of the goodbye potluck that we had, maybe because I was too busy eating. We might have lost Derek, but the others of us who were scattered far and wide (Moorea, Ecuador, Oregon, China) have begun making their way back to us. François is the last holdout, extending his holiday until the last possible minute, and maybe just a little beyond. I know they have calendars in France, François! 2010 here we come!