Cold Acclimation Green Crab Experiment Part 10

We have experimental animals!

After an unsuccessful run at a local bait shop, Carolyn managed to get crabs from a bait shop in New Bedford! It took 10 gallons of crabs to get enough blue-yellow orange crabs for the experiment. Here’s a quick rundown of what we did each day.


  • Got our first batch of crabs!
  • Sorted by sex and color. We separated out orange to red crabs and then separated our remaining crabs into males and females. We had 56 crabs total that were an acceptable color
    • It’s likely the reason why we have so many red crabs is because the crabs haven’t had their first molt of the season yet
    • We had to be less picky and allow crabs through yellow-orange to use in the experiment. Because they’re going to be kept in colder temperatures, they shouldn’t speed through integument colors quickly. The experiment this year is also shorter so we should be okay.
  • Distributed crabs to tanks
    • Since we only had 56 crabs, I opted to sort crabs into three tanks per temperature treatment. If we get more crabs, we may be able to fill out one more tank per treatment
    • T1: 6: 2F, 4M (2, 4, 7, and 9 died)
    • T2: 6: 1F, 5M (20, 22, and 23 died)
    • T3: 6: 2F, 4M (37, 39, and 42 died)
    • T4: N/A
    • T5: 8: 2F, 6M (73 died)
    • T6: 8: 3F, 5M (93 and 95 died)
    • T7: 7: 1F, 6M (111 and 117 died)
    • T8: N/A
  • Labelled, measured, and sampled leg joints for genotyping
    • Catlin and Heidi will update the version of this spreadsheet in the binder with the collected data next week while I’m out of town. If they have time, I’ll have them update the online spreadsheet too!


  • Walked Catlin through daily crab maintenance
  • TONS of mortality today. It seems like the crabs we got were really bottom-of-the-barrel. We had several deaths in each tank. I updated the metadata spreadsheet with the day each crab died and the survivorship spreadsheet with the number of total live crabs, live females, and live males in each tank.
    • T1: 10: 3F, 6M
    • T2: 9: 3F, 6M
    • T3: 9: 3F, 6M
    • T4: N/A
    • T5: 9: 3F, 6M
    • T6: 10: 3F, 6M
    • T7: 9: 2F, 7M
    • T8: N/A
  • Carolyn purchased even more crabs this morning! Instead of labelling and adding them to tanks, I decided to set them up in a flow-through tank downstairs. These crabs looked even ROUGHER than the ones we got yesterday, and I don’t want any of them dying and then mucking up the static tanks. I had to set up a couple of flow-through tanks for ~50 red and berried crabs for next week’s practice dissections and parasite counts anyways, so what’s one more tank? Catlin and Heidi can take the survivors next week, label them, and assign them to experimental tanks.
  • Found HOBO weights in the Redfield aquarium room and weighed down logger B in each tank! This way, I can capture the (hopefully non-existent) gradient of water temperatures in each tank.
  • While I’m out next week, Catlin and Heidi will do daily crab maintenance and update the metadata, ammonia, and survivorship spreadsheets in the binder! If they have time, I’ll have them update the electronic versions too.

Going forward

  1. Obtain and label more MA crabs
  2. Genotype MA crabs
  3. Develop heart rate protocol
Written on June 7, 2024