Checking on juveniles

Check out Jamestown’s juveniles!:

Sam and I rinsed all screens in heath stack 2 and 1. We did this by filling a tote lid with clean sea water and one person seived with the screen sort of submerged while the other person sprayed with the special nozzle.

H2_T2 before cleaning (48 days since May 9 cleaning):

H2_T2 after cleaning:

I shuffled the heath stack 2 trays around because again there was a difference in the amount of feed.

  • original order (from May 29):
    1. H2_T2 (low density)
    2. H2_T6 (extras)
    3. H2_T1
    4. H2_T7
    5. H2_T5
    6. H2_T3
  • shuffled order:
    1. H2_T3
    2. H2_T5
    3. H2_T7
    4. H2_T1
    5. H2_T6 (extras)
    6. H2_T2 (low density)

counting juveniles

Sam and I attempted to count the juveniles from H2_T2 (low density) by following [the method Matt previously showed me] ( They filled up about 20mL in the graduated cylinder. After counting > 300 and only being ~1/4 the way around the circle, maybe even less, we determined the we should wait until the animals are bigger to do counts.

sizing juveniles

Sam and I took pictures to get sizes on juveniles from H2_T2 and H2_T6. They are around 2-4mm.

H2_T2: H2_T6:

Waterchem Status

One Apex is down and may need servicing

Working Apex currently has:

  • 3 probe sets (pH, temp) for maintaining heath stack 1
  • 3 probe sets for new experiment with animals from heath stack 1

Ideas for pH x temp experiment


  • 2 low pH probe for low pH conicals (high and low temp)
  • Heaters plugged into apex temp probes
  • use heath tray as alternating water source and animals (12 trays total: 4 header trays and 8 rearing trays)
  • cascade set up with screens
  • do discrete measuremnets on all trays


  • for protein assay, Sam’s idea for sampling animals:
    • use whole animal and pool animals from same treatment, split homogenate across multiple assays
  • for respirometry:
    • Sam normalizes by average shell length
      • does this correlate with respiration rate?
      • could do total shell length? maybe that’s essentially the same?
      • 5 animals = enough to elicit signal

Sam’s plans:

  • Outplanting heath stack 1 juveniles in early August