And I'm not kidding either...
Case in point: This is a picture of an O. universa. We caught this lovely specimen this past summer on Catalina Island. You can clearly see its thin calcite spines, symbionts around the sphere, and juvenile inside the recently formed adult sphere. This little critter is less than a millimeter wide... with spines perhaps 4 mm. This species is quite photogenic. Really. It has even adorned the cover of Science.
Here is another beauty: this one was caught in a plankton net. It has broken spines (which later re-grew) because the plankton net often beats the forams up a bit. Even those with no spines can recover. This one had a very new final chamber and you can clearly see the juvenile trochospiral shell on the inside and the cytoplasm that is starting to infill the final sphere.
Other foraminifer species are equally beautiful. Especially those deep dwellers... I admit, I'm biased because I've spent a LONG time studying them. Mostly, I have used their geochemistry to infer changes in the earth's climate. More recently, however, I've delved into understanding how they tick... especially these lesser known deep dwelling species that are more difficult to study in laboratory conditions. I guess I like a challenge. The deep dwellers are really quite beautiful too. Take a look below... Really. Go. Look. You won't be disappointed. I'll upload more photos soon.
This foram was captured with a brand new chamber. The chamber wall was so thin that when the foram 'went benthic' within the culture jar, the wall of the new chamber 'stuck' to the jar and was pulled into a deformed shape when the foram tried to move. This is exactly how the final chamber formed, only it added about 20-25 microns of calcite in culture. It has a very thick crust and the final chamber was shaped exactly like you see here...
These are four N. dutertrei in different stages of ontogeny. The upper left specimen would have likely added another chamber. The second from the left would have been a very large specimen had it been given a chance to add more chambers. All four specimens were photographed, transferred into small vials, and then fixed in glutaraldehyde/paraformaldehyde for TEM analysis.
Last year, we brought a CTD with us to Catalina Island for our culture work. It was the first year (that I'm aware of) that a CTD has been used for culture work at Catalina. In the past, a CTD (which stands for conductivity, temperature, depth) wasn't necessary because divers collected the shallow dwelling spinose forams within the mixed layer and at shallow depths (usually less than 6m). I study forams that live MUCH deeper in the water column, far too deep for divers to collect the specimens by hand (25-55+ m). While we still have divers in the water collecting the spinose specimens (we have many collaborators interested in the spinose forams) we are also doing plankton tows to collect deeper dwelling species. The CTD has been very useful in helping us determine the depth at which we should target our tows. Studies have suggested that the depth habitat of N. dutertrei, the species we are culturing, is associated with the depth of the chlorophyll maximum. This year, Ann (Co-PI-Dr. Ann Russell) had a fluormeter added to the CTD so that we could also locate the chlorophyll maximum and target our plankton tow depths. We typically bring the CTD out with us, do a CTD cast, put out two nets (one shallow and one deeper). We then download the data back in the lab and we can compare the abundances of forams collected with the depth of the Chl-Max AND (importantly) use that data to target the depth of our next tow. We typically don't download the data on board because divers are usually on the boat at the same time - which makes for a REALLY wet boat - not a great place for a computer. But, we've found that often the water masses change so quickly here that by the time we go out on another collection, the chlorophyll max may be a bit deeper (or shallower).
What have we learned so far about the deep dwellers and their abundances? Well... sometimes we don't find ANY N. dutertrei in the Chl-max. Abundances are quite low this year and juvenile specimens (those that are ideal for culture) peaked just after the full moon. Two weeks after the full moon, abundances were still high, but the specimens are HUGE. So big, in fact, that they will do nothing in culture except die (too big add chambers). We have a hunch that the next round of very small specimens will peak after the next full moon. O. universa abundances typically track the lunar cycle and this year, that has been the case. Perhaps this will hold true for N. dutertrei. We have found that 'typically' N. dutertrei abundances are correlated with the Chl-Max (though those specimen are fully calcified and at the end of their life cycle) and abundances of juveniles (depth of which varies) may be correlated with a periodic reproductive cycle that may be correlated with the lunar cycle. Sure is a lot of correlated correlations!
Coming up in the next post... new chambers vs. pre-gametogenesis... pictures and more!
Another field season on the lovely Catalina Island has officially begun. Actually, it began over a week ago... and I'm just now getting to my first blog. More will come as we settle into a routine, but it has been SO busy that it has been difficult to find the time to write.
This year, I brought a GoPro... I will eventually rig it up to take fun field pictures like attach it to the plankton net and have the divers take movies of our collection process. Yes, this has been done before, but it's a new season and it's fun do document every year we are out here. This is my first time using a GoPro... it did give a great (and kind of weird) view of us on the boat today. We went out for a plankton tow only - no diving today. We don't dive on the weekends because of the boat traffic due to the mass exodus of weekenders leaving the island and the increased boat traffic. Doing a plankton tow is o.k. though. Today we were attempting to see if we could find more forams by doing multiple discrete tows. We only have one open/close net so we spent a few hours on the water. And had a bit of down time as you can see... It was a great day. I also took a few pics of the lab we work in. Here are a few of my favorites.