We have several experiments and projects running at the same time, but a few notes on the Pisaster work - a much crazier project than I knew when we started planning it...
One thing that is crazy: we have in custody 22 (now 21) of the Pisaster from the FHL field domain, about 1km of coastline, and of course everybody here is quite interested in making sure we return all of these seastars healthy to the rocks they came from. (We are down to 21 because one was injured and we put it back rather than stressing it out). So there is considerable ethical debt here: I worry all my waking hours about their health, even as I am intending to stress them out in the heated flow tanks pictured above.
The stress is to see how different genotypes respond to stress, and we can learn a lot. But the stress itself is... stressful. Getting this tank setup involves a lot of accidental near-electrocutions (thank goodness for GFCI outlets), tubing that gets trapped and expands into blocked-up sausages of sea water, days where the tanks drift up in temperature higher than we want, or suddenly get flooded with fresh seawater and they are colder than we want. So, if I were to do this again, I would have shipped my $1500 flow-through heater that has a lot more horsepower than the aquarium heaters we are using.
Then the seastars themselves, we have to maintain their unique identity throughout this experiment. But guess what? They all look very much alike. Here they are almost all purple, we have a cohort that are mostly very similar sizes. We have measured their arms but that is a somewhat variable thing depending on their hydration and health status, among other things. So, we caged them for the temperature trials. But one of them jammed an arm through the Vexar and got stuck, and then (they aren't smart) started twirling itself trying to get loose, nearly ripping its arm off. I freed it just in time.
The students are doing a great job keeping an eye on the whole precarious system, and fortunately we only have another week or so before we can start the remaining behavioral and tissue trials and return these gorgeous brainless deuterostomes to the wild. I will be relieved, and hopefully we will learn something interesting from it all.