Green Crab Experiment Part 8

Treatment Days 18 through 22

Day 18

  • Checked ammonia concentrations in all tanks
    • T1: 1.0
    • T2: 0.25
    • T3: 8.0
    • T4: 1.0
    • T5: 0.25
    • T6: 8.0
  • Cleaned all tanks, performed water change for all tanks, and added 1/2 tsp conditioner to T1, T3, T4, and T6
  • T3: 1 crab on top; T6: 2 crabs on top
  • 2 dead crabs in T6 (1 YG M, 1 YG F)
  • Fed ambient and warm tanks 1/4 tsp, cold tanks 1/8 tsp
  • Time-to-right for seven crabs in each tank
  • Obtained HOBO data
    • yrv_4, yrv_10, yrv_13 low battery but still recording

Day 19

  • Checked ammonia concentrations in all tanks
    • T1: 2.0
    • T2: 1.0
    • T3: 8.0
    • T4: 2.0
    • T5: 1.0
    • T6: 8.0
  • Cleaned all tanks, performed water change for T3 and T6, and added 1/2 tsp conditioner to all tanks
  • Fed ambient and warm tanks 1/4 tsp, cold tanks 1/8 tsp
  • LED light didn’t turn by itself

Day 20

  • Checked ammonia concentrations in all tanks
    • T1: 1.0
    • T2: 0.25
    • T3: 8.0
    • T4: 1.0
    • T5: 0.25
    • T6: 8.0
  • Cleaned all tanks, performed water change for T3 and T6, and added 1/2 tsp conditioner to ambient and warm tanks
  • Fed ambient and warm tanks 1/4 tsp initially, cold tanks 1/8 tsp. Fed an extra 1/4 tsp to ambient and warm tanks since there was no food left in the tanks when I went to clean
  • T6: turbid and bad smell
    • 3 dead crabs: 2 Y/YO males, 1 O female (color on carapace fading after death)
  • LED light didn’t turn by itself

Day 21

  • Checked ammonia concentrations in all tanks
    • T1: 1.0
    • T2: 0.50
    • T3: 8.0
    • T4: 1.0
    • T5: 0.50
    • T6: 8.0
  • Cleaned all tanks, performed water change for all tanks, and added 1/2 tsp conditioner to ambient and warm tanks
  • All food eaten in ambient tanks, food still remaining in warm tanks
  • T3: 1 orange male dead
  • T6: Temperature got too low after cleaning tank (turned heaters off while cleaning to drain water without exposing heater). Turned heaters back on, temperature rising when leaving.

Day 22

  • Protocol for today
    • Performed TTR for all crabs. Sexed, gauged color, measured, and weighed each sampled crab, then labelled each crab with a number. Based on weight (20-30 g), we selected crabs for respirometry.
    • Acclimated three selected crabs for one hour
    • Measured oxygen consumption. The goal was to measure consumption until the chambers reached 75-80% oxygen.
    • Removed crabs from the respirometry chambers. Resealed the chamber and measured background respiration for 20 minutes. Empty chambers and wipe down with 70% ethanol.
    • Use refractometer to get salinity measurement for acclimation tank
    • Obtained HOBO data
    • Notes
    • Usually set up acclimation for one tank while performing TTR for the next tank
    • Recalibrated probes before each respirometry run
    • T6: 1 F YO
    • T6 reading at 22ºC at the beginning of the day
      • Turned both heaters on and off, still reading too low.
      • Finished T3 tank first and then moved T6 crabs to T3 to measure last and retain at a warmer temperature
      • Temperature was too low for one whole day, meaning that the tank never reached the appropriate temperature after I left the day before. Oops.
  • Tank order
    • T3
    • T2
    • T5
    • T1
    • T4
    • T6
  • Salinity
    • T1/T4: 35
    • T2/T5: 34
    • T3/T6: 35
    • Checked ammonia concentrations in all tanks
      • T1: 1.0
      • T2: 0.25
      • T3: 8.0
      • T4: 1.0
      • T5: 0.25
      • T6: 8.0
  • Took down the experimental set-up and cleaned everything!

Going forward

  1. Update protocols
  2. Organize project repository and datasheets
  3. Update methods
  4. Start analysis!
Written on July 26, 2022