Today I sampled oyster larvae at 8 days post fertilization out at Point Whitney following broodstock PolyIC spawning.

Overview

We followed the same procedure generally as I detailed on 10 October.

I also exposed the 10K Seed to another round of PolyIC exposure.

Larval sampling and rearing

Today I sampled larvae when Carrie dropped all of the 1K L tanks. We followed similar protocols to the link above for 10 October sampling.

We dropped all of the tanks onto 80 um screens. The larvae were very pigmented and concentrated! All tanks returned similar yields onto the screens.

Larval rearing conditions in these tanks have been consistent (see notebook images below).

We then rinsed the larvae through the following screen sizes:

• 180 um (catch debris)
• 105 um
• 80 um
• 60 um
• 30 um

Larvae were rinsed and we looked at the screens for 105 um and 80 um. Very little larvae were passed through to the 80 um with the bulk on the 105 um. We therefore decided to cull the 80 um and keep the 105+ um larvae for both the control and treated groups.

Here is what the 105 screens looked like:

Here is the 80 um screen:

We looked at the larvae under the scope - they looked great! Larvae were large and the guts were full in both treatments. There may have been some smaller runts in the treated tanks, but there was not a clear difference in size.

Control larvae:

Treated larvae:

Once the larvae were isolated on the 105 um screen, I took samples by scooping concentrated larvae into tubes with 500 uL RNA/DNA shield.

• Tubes 31-45 = Control
• Tubes 46-60 = Treated
• n=15 per treatment

Samples were taken home and put in the freezer.

Sampled from 09:00-09:30.

After sampling, we weighed the larvae by pouring the larvae into a coffee filter and weighing. Point Whitney has established that 4 g of concentrated larvae equal 1 million larvae.

• Control = 198 g * 4 g / million = ~50 million larvae
  • We started with 54 million larvae - survival is ~ 91%! Typical at PW is 60%.
• Treated = 108 g * 4 g / million = 27 million larvae
  • We started with 29 million - survival is ~ 93%!

We have great survival and growth in both treatments.

Larvae were then returned to the 1K tanks. We cleaned and refilled tanks and fitted them with 105 um banjos. Added at 10:00.

• Tank 5 = 13.5 million larvae added (Treated)
• Tank 6 = 13.5 million larvae added (Treated)
• Tank 7 = 16.5 million larvae added (Control)
• Tank 9 = 16.5 million larvae added (Control)
• Tank 10 = 16.5 million larvae added (Control)

Ideal stocking is ~ 13 million, so we are right on track.

I changed the tank assignments for treatments for this next round of rearing.

Carrie will let me know when the next drop will be.

10K seed exposure

I exposed 10K seed to PolyIC solution from last use from 08:30-10:30. I discarded the solution after this use.

Probe measurements

tank	date	time	temp.C	pH.nbs	sal.psu	initials	notes
5K_1	10/7/24	12:00	25.6	8.25	NA	carrie	PolyIC-larvae-control
5K_2	10/7/24	12:00	25.9	8.27	NA	carrie	PolyIC-larvae-treated
5K_1	10/8/24	09:00	22.9	8.28	NA	carrie	PolyIC-larvae-control
5K_2	10/8/24	09:00	23.6	8.2	NA	carrie	PolyIC-larvae-treated
5K_1	10/8/24	16:00	26.7	NA	NA	carrie	PolyIC-larvae-control
5K_2	10/8/24	16:00	27.2	NA	NA	carrie	PolyIC-larvae-treated
5K_1	10/9/24	16:00	27.4	8.29	NA	carrie	PolyIC-larvae-control
5K_2	10/9/24	16:00	28.2	8.32	NA	carrie	PolyIC-larvae-treated
5K_1	10/9/24	09:00	23.6	8.4	NA	ash	PolyIC-larvae-control
5K_2	10/9/24	09:00	25.4	8.42	NA	ash	PolyIC-larvae-treated
5K_1	10/10/24	08:30	23.2	8.07	30.9	ash	PolyIC-larvae-control
5K_2	10/10/24	08:30	23.2	8.06	30.97	ash	PolyIC-larvae-treated
1K_5	10/10/24	10:30	30.5	7.85	30.89	ash	PolyIC-larvae-control
1K_6	10/10/24	10:30	30.7	7.84	30.92	ash	PolyIC-larvae-control
1K_7	10/10/24	10:30	29.9	7.81	30.99	ash	PolyIC-larvae-control
1K_8	10/10/24	10:30	29.9	7.81	31	ash	PolyIC-larvae-treated
1K_9	10/10/24	10:30	29.5	7.85	30.84	ash	PolyIC-larvae-treated
1K_5	10/15/24	08:30	28	7.83	31.01	ash	PolyIC-larvae-control
1K_6	10/15/24	08:30	28.2	7.8	31.1	ash	PolyIC-larvae-control
1K_7	10/15/24	08:30	28.2	7.8	31.04	ash	PolyIC-larvae-control
1K_8	10/15/24	08:30	28.3	7.8	30.99	ash	PolyIC-larvae-treated
1K_9	10/15/24	08:30	28.2	7.81	31.05	ash	PolyIC-larvae-treated
outdoor_tray	10/15/24	09:00	12.5	7.64	30.45	ash	top
outdoor_tray	10/15/24	09:00	12.4	7.6	30.51	ash	middle
outdoor_tray	10/15/24	09:00	12.4	7.58	30.52	ash	bottom
upweller	10/15/24	09:00	14	7.79	30.06	ash	broodstock
upweller	10/15/24	09:00	13.8	7.81	30.11	ash	efforts BED
dock	10/15/24	09:00	13.5	7.82	30.2	ash	seed
1K_5	10/11/24	09:00	27.6	8.36	NA	carrie	PolyIC-larvae-control
1K_6	10/11/24	09:00	27.8	8.35	NA	carrie	PolyIC-larvae-control
1K_7	10/11/24	09:00	27.2	8.34	NA	carrie	PolyIC-larvae-control
1K_8	10/11/24	09:00	27.4	8.33	NA	carrie	PolyIC-larvae-treated
1K_9	10/11/24	09:00	27.5	8.34	NA	carrie	PolyIC-larvae-treated
1K_5	10/12/24	09:00	27.4	8.27	NA	carrie	PolyIC-larvae-control
1K_6	10/12/24	09:00	27.9	8.27	NA	carrie	PolyIC-larvae-control
1K_7	10/12/24	09:00	27.6	8.26	NA	carrie	PolyIC-larvae-control
1K_8	10/12/24	09:00	27.4	8.25	NA	carrie	PolyIC-larvae-treated
1K_9	10/12/24	09:00	27.6	8.24	NA	carrie	PolyIC-larvae-treated
1K_5	10/13/24	09:00	28.2	8.23	NA	carrie	PolyIC-larvae-control
1K_6	10/13/24	09:00	28	8.24	NA	carrie	PolyIC-larvae-control
1K_7	10/13/24	09:00	27.6	8.22	NA	carrie	PolyIC-larvae-control
1K_8	10/13/24	09:00	27.5	8.21	NA	carrie	PolyIC-larvae-treated
1K_9	10/13/24	09:00	27.8	8.25	NA	carrie	PolyIC-larvae-treated
1K_5	10/14/24	09:00	29.2	8.21	NA	carrie	PolyIC-larvae-control
1K_6	10/14/24	09:00	29.4	8.2	NA	carrie	PolyIC-larvae-control
1K_7	10/14/24	09:00	29.1	8.2	NA	carrie	PolyIC-larvae-control
1K_8	10/14/24	09:00	29.1	8.17	NA	carrie	PolyIC-larvae-treated
1K_9	10/14/24	09:00	29.1	8.2	NA	carrie	PolyIC-larvae-treated

Fluorometry measurements ranged from 10-20 in early rearing and increased to 20-30 in later rearing.

Flow was 1.4-1.8 in all tanks.

Notebook images