Grats Terry, Megan and Christy!

Our APS DFD gallery of fluid motion video has found its way to the blog at newscientist.com. They did a nice job with the video! http://www.newscientist.com/blogs/nstv/2010/11/fluid-nature-psychedleic-jellfish.html

I know that I promised to post more videos on the blog and website. Now that it is the start of the new year, maybe I will actually find some time to make updates! We do have some new simulations of leaves (or flexible plates) fluttering in the wind. I'm also hoping to get more videos of the jellyfish soon.

New jellyfish flow visualization movie.

After much work Thursday and Friday, we finally got all of the pieces together for our APS DFD gallery of fluid motion entry! You can see the final result here: http://www.youtube.com/watch?v=aNu3ErorsDM

We still need to do some work with the fluorescein, most of the video was over saturated. It's possibly harder to do proper flow visualization with the upside down jellyfish because you can't inject a little cloud of dye for the jellyfish to swim through. Also, the elaborate oral arms do a good job of breaking up the streams of dye.

I'd also like to give a big thanks to Christy Hamlet for making last minute videos of her immersed boundary simulations so that we would have enough footage to complete the video and create a good story line.

I think this video ended up better than our first attempt at the fluids gallery, but we still have some work to do. My goal is to start working on next year's video now (rather than next fall) and perfect all of the techniques.

New jellyfish are here, and sea squirts too!

We finally got in our jellyfish orders and they appear to be happy in our aquaria! We have the tank next to the window so that they are getting both natural and artificial light. We've also added sea squirts to the tank this time around with the hopes that they will keep the algae under control. Stay tuned for some pictures and movies.

Or maybe not

We were contacted last week that there would be no new jellies due to a death in the family of the suppliers. Invertebrate suppliers are usually locally owned, small-scale operations so this is not unexpected. The new shipment looks to arrive around the 27th. We'll be waiting!

New Jellies

We should be getting in some new jellyfish today. Most people are going out of town next week, so it's good we can get them nice and settled before we leave. Megan is doing an outstanding job of taking care of the tanks.

Welcome Megan Gyoerkoe

We have a brand new lab tech, Megan Gyoerkoe!

Megan will be wrangling with the jellyfish for the summer. So far she's been working on removing the algae from the walls of some of the older tanks in preparation for the arrival of some new jellyfish and tunicates. She's done a great job so far, hopefully we'll be able to convince her to stay in the fall!

We're hoping to be able to handle a new shipment some time next week. I'll try to post some pictures of the tanks in their current states.

We're in our new home of Chapman 303 for now and we're enjoying the joys of a sink. It looks like there will be construction going on in Chapman during which we may have to relocate to Phillips again. We're thinking of moving the tanks to the one room we have with a sink, though it may be tight in there. After all of the dust clears (no pun intended) it looks like we will have rooms on the 3rd and 4th floor of Chapman. The aquaria will be in their own room on the third floor and the electronic equipment will have a home on the 4th floor. Things seem to be moving slowly but steadily toward finding a home. The jellies are very excited.

Welcome Walt Rogers

We have a new undergraduate lab technician, Walt Rogers, who is joining us from the Dept. of Marine Sciences. Walt is currently working on redesigning the tanks. He's doing a great job of feeding and maintaining the tanks, and he seems to have some good ideas for tank design.

The algae in the newest tank turned out to actually be a very neat-looking and apparently very toxic blue-green algae. We also had a nice diatom bloom to go with it. Together these two managed to kill all of the jellyfish and most of the snails in the tank. The anemones, serpent star, and crab seem to be okay. We're going to play musical tanks and try to clean everything as we go. I'm not sure whether the live rock has been contaminated, so I'm a little trepidatious about transferring it once the new tank is set up.

It will take a while to get the tanks up and running for jellyfish, so experiments have been put on hold for a while. I don't know what this means for my project, but for now I'm just working on numerical simulations and math modeling. Hopefully once the tanks are up again, I'll be able to get lots of data from the next batch of jellies.

Made it on TV!

We finally made it on TV! Check it out to see our live and mathematical jellyfish: http://watch.discoverychannel.ca/daily-planet/january-2010/daily-planet---january-11-2010/#clip254460

It was quite a challenge to fit everyone into our tiny lab rooms (converted offices). The jellyfish are a little hard to see from the algae bloom as well :) Overall, I think it turned out well despite the limitations, and hopefully we will be moving into a new lab space this summer in Chapman Hall!

Scrubbed and clean

I spent the morning scrubbing salt and cleaning tanks. The mysterious algae in the newest tank seems very persistent. I scrubbed it off the front, so it moved to the back. I scrubbed the back, it moved to the front. And so on. It leaves small green thread-like strands on the tank when I scrub and there is a brown substance that aggregates onto the strands in a few minutes. I scrubbed what I could, hopefully the filters will get some of it. I dropped the light duration in hopes it will starve the algae. We still need to get plexiglass cut for the tops and to work on getting more flow through both compartments.

A new year

It's been a while since our last post! Since the last time we got another stock of jellyfish. There was an algae bloom that I suspect was releasing toxins into the water because even the snails died on that end of the water. The side with the other critters seems okay, so I'm not sure what the difference is. We put another filter on that side and I'm hoping it will clear up.

In the meanwhile, there is one jellyfish from the previous batch that is still kicking, so I'm feeding him and hoping he'll bounce back. All of the other organisms are okay it seems. We switched to a broader spectrum flake food after the arrow crab died, and I think everyone is happier. Apparently we are very good at keeping everything EXCEPT jellyfish alive.....

I'm planning on switching to submersible heaters exclusively as they are easier to maintain. Water loss is still a problem. I've been a little remiss in getting the plexiglass tops cut. We're waiting to hear about labspace and it's been very cold outside, so experimentally the jellies are on hold until we can care for them better and be able to take them back and forth to Wilson for dissection, etc.

Tank the second

The current stock of jellyfish is shrinking like the last specimen of the first group. We think this is because we aren't feeding them enough and they are consuming their bell for sruvival. We're considering switching to a several times a day small feeding schedule. I'm still hopeful that at least some of them will bounce back.

The new tank is now filled with water and the filter is up and running. We need to finish transferring the sand. The live rock should be ordered today and will hopefully arrive well before the jellyfish.

In search of swimming fairyflies

I tried to find some of these aerial/aquatic parasitoid wasps this summer (Mymaridae), but was unsuccessful. Some of them can swim and fly by flapping their wings! They are only 0.2 mm long, so I guess I shouldn't feel too bad that I couldn't find them.

It's unclear if there are any in NC too, but a paper from 1918 claims there are some around Ithaca, NY. Maybe I will go to Cornell next summer. The ones that swim parasitize aquatic eggs, like water beetle eggs. If anyone knows where to find these guys, please send me an email.

Tank redesign

The last of our June order of jellyfish has passed, but it seems to have been a natural death. We took the opportunity to redesign the tank with 2 chambers, a biowheel filter, and a protein skimmer. We haven't had any problems with algae blooms since! We also ordered 6 new upside down jellyfish from carolinabiological.com. They seem to be doing very well. Now the last problem to solve is feeding. We have been home growing our own brine shrimp for them a couple of times a week, but this process is rather time consuming. We are going to try to make a mass amount of them and freeze them. Hopefully this approach will work!

In the meantime, Arvind has been measuring the flow velocities around the bell with piv, and hopefully he will have a draft of the paper soon so that we can submit it to the Journal of Experimental Biology. More pictures will be coming soon!

jellyfish are still alive!

As far as I know, our second batch of upside down jellyfish is still alive! This is the 1 month marker. We've also managed to take some data on the flow fields around the bell as they contract using piv (particle image velocimetry). The big problem is controlling the algae in the tank, but we've ordered a protein skimmer (to remove the debris the algae eat). We will need to redesign the tank though with a separate compartment for all of this filtering. 

The brine shrimp hatchery has arrived and I'm looking for the best place to set up. The grow light for the smaller set up seems to be working, but I don't have anything for the hatchery right now. We have no temperature control in the basement, and I think it's a little bit too cold for the shrimp. I have learned through trial and error that temperature is easily as important as light. So I'll need to find a warmer spot or find some way of heating the water.

The tunicates died back about two weeks ago. We thought we had perhaps poisoned them with the algae concentrate we had been using, but now it looks like they are growing back. Perhaps a natural life cycle? We'll see what happens this time. We discovered at least two other species of tunicate in the tank that apparently hitched in on the live rock. No idea on the identifications, but we'll see what we can find. It seems like every time I look into the tunicate tank, there is something new popping up. Very exciting!

After a false start with the first batch of Cassiopeia, we finally have a set of three gulf specimens relatively settled and happy. We're dealing with a golden algae bloom, probably hitchhikers from the jelly transport bags.

The algae cultures are snug in their new foil-lined lair. There are four cultures of distinct algae types and all seem to be growing nicely. Pictures and species names to follow soon!

Starting to put the tanks together

We just got in a 20 gallon and a 29 gallon tank and have started to set up the filtering systems for both. The first animals I'm going to order are some sea squirts, likely Clavelina picta. I've got to figure out how to culture algae to feed them before shipping them to North Carolina (it shouldn't be too hard, I hope). Once they arrive I'll definitely post some pictures!

The next step will be to order some of the upside down jellyfish like the mangrove jellyfish (see picture). Supposedly, they can be kept in normal tanks, but they don't really swim. They pulse their bell to generate currents for feeding. Since they can't see, we will be able to use particle image velocimetry (piv) to quantify the flow fields around the bell without worry of harming them with the laser.

Setting up salt water tanks

Now that we have a few rooms in the basement of Phillips Hall (and I have a little bit of time), we are going to try to set up a couple of salt water tanks. I'd like to try to keep the sea squirt Ciona savigny in the lab and use it to measure fluid flow induced by cilia and contractions through the siphon and body. We're going to try to do this using particle image velocimetry (piv). Hopefully, the flash of the laser will not startle them. It may also be a challenge to keep them alive. They need moving water and a constant supply of food (it is harder than it sounds). If all works out, eventually I'd like to work up to taking measurements of flow rates in their heart and blood vessels.

The next step is going to be to keep some jellyfish alive in the lab. This should be more exciting for students and visitors since they actually swim! The problem is that these animals do not do well with walls. They have a tendency to slam into them and get stuck. Supposedly, cylindrical tanks with a jet that flows around the wall can keep them in the center of the tank and happy. If we can get this to work, we should be able to get spatially and temporally resolved flow fields as they swim. John Dabiri at Caltech has gotten excellent data from these animals already. Hopefully we can reproduce some of the work as an outreach tool. 

 

Welcome to the Math Physiology Group's Blog!

Hopefully this will be a good way to keep group members and friends up to date on what is going on in our new math physiology lab at UNC. I'll post some information soon about our attempts to bring in sea squirts and keep them alive in Phillips Hall Basement!