Monday, November 23, 2009
In the picture below, Jenna is spreading the Geneious love. She is now so skilled in the program that she is sharing her knowledge with others. JD is hanging on her every word. Also, Julie is delighted by ossicles, the calcarious particles in the skin of sea cucumbers. She is preparing slides so the ossicles can be viewed under a microcscope. They are often a diagnostic character in distinguishing species.
John is taking a break from the land snails of Madagascar to ID some snails that were given to us from marine lakes in the Pacific. Not to worry, the 10,000 lots of land snails that recently arrived from Madagascar will not let themselves be forgotten. They have numbers on their side and know that John needs them for his PhD work.
Before we put tissue samples in plates to be sent off and sequenced, it is helpful to have an accurate ID on the specimen, so Gustav called for backup. Harry Lee is an expert malacologist whom Gustav recruited to help us ID to species some of the snail families in our collection.
Jada and Anthony are plating some some her Moorea specimens for sequencing. Not pictured, the actual plates. I think they're hidden behind a bag of subsample vials.
This was Walter's highly anticipated vermetid ID-stravaganza. As you can see it was well attended, even though it was postponed until Thursday due to schedule conflicts. These worm snails can be easily confused, not only between species, but with other families of snails such as the Turritellidae, and even with actual worms, a completely different phylum (Annelida). We are now armed with the necessary arsenal to fend off such mis-IDs.
We have a shortened week due to the Thanksgiving holiday. After gorging ourselves on turkey we'll be ready to spring back into action. Or if not spring, at least sluggishly haul ourselves up to our desks.
Friday, November 20, 2009
For the last few years our lab has been involved in putting ARMS on reefs. These are Autonomous Reef Monitoring Structures. The idea was to come up with a standardized unit to measure reef biodiversity. Each unit consists of PVC plates, spacers, and some wire mesh. The whole thing is anchored to the reef, and left to sit and get settled for a full year.
With Creefs back at Heron island for another season of biodiversity surveying, it was time to pull out the ARMS that had been placed last year. The video is of Shawn removing an ARMS from the bottom, and carefully boxing it and carrying it to the surface.
Taking them apart and sampling them fully is time intensive- and quite a few of the species we have gotten so far have not come from any other method of sampling, including the "Muppet Crab" featured at the bottom of the post.
The ARMS is carefully released from it's box....
The layers are unbolted
The mesh layer is on top.
Then several PVC layers
Everything is brushed carefully and all obvious creatures and plants are removed.
Everything is carefully rinsed and the rinse-water strained for small organisms
And then the specimens are carefully sorted to species in the lab.
And the treasures appear!
Wednesday, November 18, 2009
Enjoy. I sure did.
Monday, November 16, 2009
Take a look at these pictures and see if you can tell who went to Paris with John and who went to France at the Epcot Food and Wine Festival.
Gustav also returned bearing gifts. In addition to several hundred specimens from Moorea (a small sampling of what we will face in December when the whole expedition heads back to Gainesville), Gustav also brought some of his field notes for us to enter into a spreadsheet. We had already begun this task on Sarah's behalf so we knew what we were facing.
If you can read this you're either a huge invert-nerd, a cryptologist, or Gustav. Don't limit yourself, you might be more than one.
A couple more pictures of what we've been up to: Jenna is becoming a genius at Geneious, a software program for aligning DNA sequences.
We aim to sequence to bulk of the species in our ethanol preserved collection in the coming months.
Also, Derek has begun tackling the crab family Portunidae, the swimming crabs. Using a key (and the assistance of Gustav) he has been assigning the correct species name to the specimens which have either been unidentified (or identified only to family level) or misidentified in the past.
Walter Kelly has also been busy identifying our collection of vermetid snails (family Vermetidae) and will be giving a presentation later today which will turn us all into expert vermetid IDers. Ok, maybe it'll take more than a day, but we can dream can't we, and we'll still have Walter around for a while to show us how it's done.
I hope all you field agents are remembering the sunscreen as you languish on various tropical isles!
Thursday, November 12, 2009
Wednesday, November 11, 2009
First impressions of the Southern Great Barrier Reef: Diversity is high, with a few species familiar to us from Polynesia, but most are new. Decapod abundance seems lower in comparison, but that could just be the microhabitats that we dove on yesterday. One thing does appear to occur in serious abundance: parasitism. In the samples from Biocode on Moorea, it is an unusual occurance for us to encounter a parasite on a crustacean or seastar- perhaps one in one hundred. Here in Australia the rate seems much much higher- perhaps one in five.
Here is an externally parasitic snail, Thyca, on the seastar Lincka multiflora
And here is an internally parasitic snail, Stylifer, on the same species of seastar.
Understanding the pattern behind these differences is the trick. Part of it may be that diversity begets diversity, creating what Phillipe Bouche has called "the russian dolls of biodiversity." This is where one organism may have a commensal organism living with it, that commensal may have a parasite, and that parasite may have a parasite. We certainly see it with coral, where one species of coral may host many symbionts and each of these may have their own set of commensals and parasites. By increasing the number of species of structural species (corals in this case, but could just as easily be trees in a rainforest) by one, we increase the over-all diversity by many.
This Pink Coral Guard Crab (Trapezia serenei) is a good example. It lives exclusively in one family of corals. If you look at the carapace, you can see that it is asymetrical. In this case that is indicative of a Boporid- a crustacean parasite on crustaceans that has infected the crab.
Tuesday, November 10, 2009
The island is absolutely alive with birds. During the day, noddies, egrets, rails, and plovers go about their business with cacaphonous ablomb. Now that the sun is setting, the shearwaters are arriving in droves, crash landing into people and buildings, then running to their nests in burrows in the sandy soil. It is new and amazing, though I am told that after a few weeks, you relish the comparative silence to be found underwater.
Our first dive will be tomorrow, so tonight we are setting up our equipment. We are here as part of the CReefs program to explore and document tropical marine biodiversity. As with Biocode, the efforts revolve around bringing in taxonomic and systematic experts to quantify as many taxa as possible during the short time we have here. FLMNH is represented by three people: Francois Michonneau, an expert in Holothurians, Rob Lasley who works on crabs, and myself, working on coral symbionts.
What can you find in the photo above? Many of the organisms that our group studies are cryptic- hidden in their environment. Sometimes a trained eye can spot them- a slightly different texture, motion slightly out of sync with the rest of the setting- but most of the time we swim right past, just like everything else. When people think of the biodiversity of a coral reef, most think of colorful fish, or the corals. Yet the real bulk of diversity, and some of the most amazing creatures are the little things, the hidden things.
An interesting idea to think about is the coloration of reef creatures. Out of their habitat, some appear very colorful- almost psychedelic. But when placed on the reef with it's complex colors and shapes, they disappear. A good example of this is the shrimp Saron, photo below.
Both crabs and shrimps are very good at hiding, and several families of each group have specialized in crypsis, or camoflaouge. The family Majidae, or 'spider crabs' are a great example. Some members of this group are known as 'decorator crabs' because they gather material from the world around them and attach it to their shell and legs in order to hide.
Others, such as the shrimp family Crangonidae, rely on the coloration of the body itself to provide the protection. Can you find the shrimp in the photo below?
So how are you doing with that photo at the top? Here's a photo of the Leucosid crab that is in sand. See it now?
Thursday, November 5, 2009
It turns out that it belongs to a group of nemertean worms that are active predators on crustaceans such as crabs. The original discovery of the group was made in Panama where a researcher studying the behavior of fiddler crabs repeatedly saw crabs suddenly freak out, making erratic motions. When he waded through the mud to get the crabs, they had been emptied- sucked dry. It turns out that a nemertean was lurking in the sand. When it detected the shadow of a crab passing overhead, it would harpoon it with a sharp stylet borne on its proboscis, enabling delivery of a dose of neurotoxin.
The worm secretes, through the same hole, digestive enzymes into the prey, rapidly liquifying the internal tissues. It then sucks out the resulting soup, leaving nothing but the exoskeleton sitting on the mud.
Now we know they are in Moorea. Crabs be warned!
Wednesday, November 4, 2009
Arthur Anker, a Postdoctoral Researcher with the FLMNH Invertebrate Zoology department, has a knack for finding the unnoticed things, the creatures that everyone else somehow misses. Here in Moorea, French Polynesia, Art has specialized in the muddy, mucky habitats that most marine biologists wouldn't stick a toe in. Art, however, thrives here, and has brought back a steady stream of new records, new species, and just plain amazing animals that don't seem to live anywhere else. Tools of the trade include a "Yabbie Pump" for pumping small animals from shrimp burrows, a range of fine dipnets, and the patience to work in two feet of muddy water for most of the day.
A few of Art's finds follow, but many more can be found on his flickr stream.
Tuesday, November 3, 2009
Pteropods for example, are highly modified gastropods, or snails- some of which have given up their shells in trade for a 'flying' lifestyle, with two beating fins or wings. Salps are the open ocean forms of ascidians ("sea squirts") that use the powerful water pumping system evolved originally for filter feeding, for 'jet propulsion' in the open waters.
The system truly belongs to the jellies- both the Medusae ("jellyfish") and the Ctenophores ("comb jellies"). In the deep water, without obstacles to bump into, the jellies have taken on a diversity of form unrivaled in the blue. Some are 'traditional' and have a rounded body with hanging tentacles. Others are not so conservative, and resemble nothing so much as actively moving lotus blossoms, fanning open 'petals' as they drop and recoil tentacles in an effort to catch even smaller members of this world.