Now, a month later, those three tanks look like this:
So, we know I can grow algae.
By this time, I’ve uncovered a few inconsistencies in my experiment. It turns out that light is emitted from a bulb in diagonal directions as well as straight down (no big surprise there) so the middle tank gets considerably more light than those on the ends. This was more obvious at the beginning of May, when the middle tank was a nice dark green but the other two had barely gotten started. I’m hoping that from a zoe’s point of view the food-supply is near infinite in all three tanks, but there may be differences in growth rate. (A store that sells frozen Tetraselmis claims better growth rate with frozen algae over live algae because less energy is spent in foraging. A difference in food density may change the growth rate for similar reasons.)
The other inconsistency is that the middle heated tank is a degree or so warmer than the rightmost. That’s due to laziness — I’m tired of fussing with the thermostat and I can’t get things quite right.
On account of the warm spring, the leftmost tank is warmer than I’d planned, nearly 70 degrees. I’m most interested in whether or not growth is stopped altogether by winter temperatures in the 50’s, but I’ll have to wait until winter to learn about that.
Meanwhile, the eggs look close to hatching. By this time nearly all of the females are carrying eggs, so it’s hard to know which one had them first — this means that I won’t know exactly how long egg development takes, although it seems to be following the expect 5-week course.
I’ve moved a couple of especially eggy females into a bowl where I can more easily collect the larvae when they hatch.
