Gigas Larvae Day 2

A bit of a rough start today

There was a miscommunciation about our use of the reservoir tank near the OA system, so the heaters in our tank were unplugged last night. I turned them back on when I arrived and added an additional heater from the oyster totes since they were at temperature. Stuart also metioned that this water may be super saturated with gasses since it’s not passing through a degassing column. I added an airstone to the tank to let it aerate better. I then took two more heaters and placed them in a 100 L tank and 200 L tank with water so the water would heat faster. Since I had to wait for the temperature in the heated reservoir to reach 20 ºC so I could use it to screen larvae, I took the HOBOs from Laura’s oysters, cleaned them and placed them in my larval buckets. While I was waiting, I saw that the temperature in some of my tanks had dropped down to 18 ºC. I wasn’t sure how accurate the temperature gun was, so I added in another thermometer to a tote without a heater, and closed the door of the SeaLab to retain heat in the room. My guess was that the outside air temperature was affecting the tank temperature. I may need to take the time to insulate the totes. To bring things back to temperature quiclky, I changed the heater setpoint to 28ºC for a brief period of time.

Once the reservoir water hit 20ºC, we started screening! We filled buckets with water from the 100 L tank, since it was at 24ºC. We then would move water at 19ºC from the 200 L tank to the 100 L tank so it could warm faster. Because those tanks had water with a lot of filth through it, we poured the water through a 100 L screen before putting it in the larval bucket. We used a 48 micron screen to catch larvae, then placed it in a tripour with 500 mL of seawater. I sampled 300 µL of the larvae for counting and imaging in triplicate and placed it in a well-plate. I fixed the oysters with Lugol’s and put the plates in the fridge for tomorrow. I also took 300 µL of sample and placed it in an eppendorf tube for either epigenetic or proteomic testing. I pipetted an 80% ethanol solution into the tubes, centrifuged the sample and ethanol, then pipetted out supernatant to rinse out any salts. There was some white stuff at the bottom of my tubes, so I hope this is actually larvae. I need to talk to Laura to see if this was the way she did it, or if she had a more efficient system.

Finally, I fed the oysters a mix of C.iso, Chagra and 609. I topped off the volume in my buckets before I fed, which was a mistake! I forgot to account of the additional volume from feeding — something I won’t do again. Because adding in food made most of the water levels pass the holes in the buckets, I quickly added in tubes, clamps and elbows to prevent water and larvae from flowing out of the bucket.

For tomorrow:

  • Feed
  • Image oysters
  • Ask Joth about heater
  • Move AVTECH to SeaLab
  • Start setting up OA systems
  • Start scoping out setting tanks
Written on August 1, 2017