Setters get bigger home, sampled SN growth trial, screened larvae

Lots to do today!

First on the agenda, Grace imaged the screened larvae from 6/19 while Olivia & I set up a tank outside (adjacent to algae greenhouse) as a downweller to hold 180um silos. This is to make room for a new batch of setters inside so I mimimize risk should something go awry with a silo. Olivia then cleaned the 2 setting tanks inside to get ready for new 224 larvae. Details on the outside downwelling setup:

• Heated line @ 14degC flows into the small side (right side in image); 1 800watt immersion heater brings temp up to ~17-18degC.
• Water flows through 1/2” pipe into each silo through a small hole drilled directly into the pipe, fed via gravity
• Water is partially recirculated via a pump back into the small side of the tank to conserve heat and algae
• Algae is dosed via gravity/dripper; directly behind this image is the greenhouse, where a Calwell tank is hooked up to a hose with a dripper, which drips into the small side of the tank.

today.

Screened larval buckets

Monday was the first time I saw high mortality in a couple the 180um groups: SN-6 Low, SN-10 Low, NF-10 Low, and moderate mortality in SN-10 ambient. I saw similar high mortality in the 180um group today, again in the SN group - SN6 Low, SN10 Ambient, and SN10 Low (but notice that the SN6 ambient group looked good). NF10 Low also took a major hit today. Ciliates were visible under the dissecting scope in the SN6 Low, and in the NF10 Low.

Collected new larvae:

Sampled larvae from SN Growth Experiment

Today is day 7 of the growth trial, so I sampled larvae similar to the method Katherine used, with a minor adjustment. I sampleed ~40-50 live larvae from each silo in a consistently random manner. Protocol:

• Lift silo out of tripour, pour some FSW from tripour into the lid of a petri dish
• Place silo in the petri dish lid (it fits perfectly)
• Using a head lamp and plastic pipette, randomly remove larvae from silo, moving into a well-plate.
• Count # larvae under dissecting scope. If more is needed, randomly sample more.
• When necessary remove water from well to make room for more larvae/water mixture
• All larvae were kept live in well plate, placed in fridge to chill/calm down so I could image them tomorrow.
• When finished sampling larvae from the silo, Grace gave them a 1min freshwater bath, then moved them in to their new FSW+algae mix and placed back on the table.

Setup with silo in petri dish lid, pipette, counter and well plate at hand

Looking for larvae with a head lamp- they are small

Freshwater bath

New water ready for silos

Algae counts for water change: