Experiment log: experiment week!

IT’S EXPERIMENT WEEK. This year I did a much better job of recording data and the students helped me with data entry. Things went relatively smoothly (shocking), and the following documents reflect what was done:

• metadata with updated death dates (molting mortality and/or dissections)
• time-to-right
• survivorship
• ammonia

2024-06-24

• Time point 0
  • Me, Sara, and Heidi
  • All crabs should be around 14ºC
  • T1 14 separated in a different tank while recovering from molting. Moved it to T1 for TTR measurements…where it was promptly eaten. RIP 14.
  • Time-to-right performed for all crabs, dissections performed on a subset of 2 crabs per tank
  • Fed remaining crabs 1/4 tsp of Hikari Crab Cuisine
• Between time point 0 and 1
  • After measurements, heaters were added to the intended 5ºC tanks (T5-7)
  • Room set to 0ºC
    • For several hours I thought the room was at 2ºC and that I couldn’t ratchet the set point lower. After bringing Dion down to Redfield and walking him through my problems, I realized that there was a dash a little too far away from the set point…meaning that the set point was actually at -2ºC instead of 2ºC. I moved the set point back up to 0ºC.
• Time point 1
  • Me, Heidi, and Catlin
  • I started the measurements for time point 1 TTR while I thought the room was at 2ºC because I figured that the water temperature would not have reached 0ºC anyways. This time point reflects the transitional ramp down to either 0ºC or 5ºC.
  • Selected a subset of crabs to follow for the course of the experiment. This included all female crabs and the least orange males
  • Time-to-right for selected subset, dissections performed on a different subset of 2 crabs per tank

2024-06-25

• Time point 2
  • Me, Heidi, and CC-CREW volunteer Colby
  • Checked HOBO loggers for tanks.
    • Everything looked good (cold tanks around ~1ºC, slightly less cold tanks at 5ºC). I noticed that T5 was slightly too cold, so I moved the heater set point from 5ºC to 5.3ºC to see if I could get it to be roughly the same temperature as the other two 5ºC tanks

    

  Figures 1-12. Temperature recorded by HOBO loggers in treatment tanks

  • Low battery warning for 7A
  • Time-to-right for designated subset
  • One crab from the designated subset was sampled, along with one random male
  • Fed remaining crabs 1/4 tsp of Hikari Crab Cuisine
• Time point 3
  • Me, Heidi, and CC-CREW volunteers Colby and Phoebe
  • Time-to-right for designated subset
  • One crab from the designated subset was sampled, along with one random male

2024-06-26

• Time point 4
  • Me and Sara
  • Checked HOBO loggers
    • Low battery warning for 1B
    • T5 was still too cold, and T6 was now too warm? Clearly I manipulated the wrong temperature control box yesterday! I fixed it by bringing the set point for T6 back down to 5ºC and increasing the set point for T5 up to 5.3ºC

    

    Figures 13-24. Temperature recorded by HOBO loggers in treatment tanks

  • Time-to-right for designated subset
  • One crab from the designated subset was sampled, along with one random male
  • Fed remaining crabs 1/4 tsp of Hikari Crab Cuisine

2024-06-28

• Time point 5
  • Me, Catlin, and Heidi
  • Checked HOBO loggers
    • Temperature in the 0ºC tanks was now closer to 2ºC. I wonder how much of this has to do with the room’s capacity for cooling, with T3 having the warmest temperature. Is that why those crabs were flipping more than the others?

    

    Figures 25-36. Temperature recorded by HOBO loggers in treatment tanks

  • Time-to-right and dissections for all crabs!
• Cleaned the cold room, tanks, air stones, and filters!

Some notes for the WA experiment

• I really don’t know when or how we can add heart rate measurements to the first four time points of the experiment since there isn’t any down time. It’ll certainly take longer to complete each time point which may lead to some longer and more intense days.
• In an ideal world, the subset for TTR should have an even balance of genotypes! Not really a concern with this experiment, but it would be important for the WA crabs
• The room could be set even lower than 0ºC to allow the tanks to get colder. Although, they already weren’t flipping at 1-2ºC, likely because they enter a torpor at 4ºC. I think I should analyze the TTR data before making any decisions for the WA crabs.

Going forward

1. Set up WA crabs
2. Genotype WA crabs
3. Finish genotyping MA crabs
4. Qubit and re-extract crabs with no gel bands
5. Develop lipid assay protocol
6. Develop heart rate protocol
7. Run WA experiment!