Whew, it's finally here! I just got my package of a small Aldrovanda Hungarian Form today. I just dropped it in my small container. Hopefully, from the warm temperatures, that the plant should rapidly start growing again. If it does, I'll be posting some pics soon. Wish me luck!
I hope you have a lot of companion plants ready for them, mostly large monocot plants, (whose roots give off a constant source of carbon dioxide while absorbing the excess nitrogenous matter given off by the Aldrovanda plants), along with some detritus and a healthy population of zooplankon (including Daphna, copepods, small snails, etc.) on which they will feed, and help groom the plants of algae. The water chemistry alone plays a very small factor in the success of getting these Aldrovanda to thrive; the Biology, (with regard to all the complex symbiotic relationships) is the key to getting these plants to thrive. Good luck! - Rich
... not suffering from insanity, but rather enjoying it actually!
That's not unusual. Aldrovanda can have as high as a 95% or more winter fatality rate, plus, with their high sugar content, they make a tasty meal for hungry turtles, ducks, geese and anything else.
Every year, in my Aldrovanda pond, I'm amazed to see them return and repopulate the way they do, often starting out from just a few solitary survivors hidden between some Juncus hummocks or under the canopy of old Carex leaf litter. Nesting mallards and Canadian geese routinely decimate the emerging Aldrovanda turions every Spring season in my pond.
About 10 years ago, when I noticed they first survived my winter, I took in about a hundred dormant turions late in November when they were hardened and about to lose buoyancy and sink into the detritus. I tried several ways of storing them in my refrigerator, some in just damp paper towels, some in damp sphagnum, some in damp peat, and some in a mix of peat, sphagnum and cedar bark mulch. Previous attempts of storing them in water proved disastrous, as they all rotted.
By early April, I still had losses of around 50% or more in all those methods, and that was relatively low. A few turions opened up only to reveal a dead center, just as yours did.
There is some reoccurring speculation that the roots of the large companion monocot plants release some signal to the Aldrovanda to begin to grow, and keep them from rotting over the winter, but no one has yet isolated any such chemical signal, other than a sudden burst of carbon dioxide when the growing season starts, which the Aldrovanda needs for photosynthesis. I suspect that the zooplankton community may have more to do with the survival of the dormant Aldrovanda instead.